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20 pages, 4594 KiB

Open AccessArticle

Potential of Ca-Complexed in Amino Acid in Attenuating Salt Stress in Sour Passion Fruit Seedlings

by Antônio Gustavo de Luna Souto, Angela Maria dos Santos Pessoa, Sarah Alencar de Sá, Nayana Rodrigues de Sousa, Emerson Serafim Barros, Francimar Maik da Silva Morais, Fagner Nogueira Ferreira, Wedson Aleff Oliveira da Silva, Rafael Oliveira Batista, Daniel Valadão Silva, Rita Magally Oliveira da Silva Marcelino, Hans Raj Gheyi, Geovani Soares de Lima, Rosa Maria dos Santos Pessoa and Mailson Monteiro do Rêgo

Plants 2024, 13(20), 2912; https://doi.org/10.3390/plants13202912 - 17 Oct 2024

Viewed by 686

Abstract

Salt stress results in physiological changes that inhibit plant growth and development. Ca-complex sources are used as a potential salt stress attenuator. This study was carried out with the aim of verifying the effects of Ca-complex sources in reducing the effects of saline [...] Read more.

Salt stress results in physiological changes that inhibit plant growth and development. Ca-complex sources are used as a potential salt stress attenuator. This study was carried out with the aim of verifying the effects of Ca-complex sources in reducing the effects of saline water stress on the physiological aspects of sour passion fruit seedlings. The experiment was carried out in a randomized block design with a 2 × 2 × 3 factorial scheme, consisting of two cultivars of sour passion fruit (BRS GA1 and BRS SC1), two levels of water salinity (electrical conductivity of 0.5 and 4.0 dS m⁻¹) and three sources of Ca-complex (without, organic acids and amino acids). The traits measured at 60 days after sowing were gas exchange, chlorophyll indices, chlorophyll fluorescence, electrolyte leakage, and relative water content in the leaf limb. Under moderate water salinity, the application of Ca-complex in amino acids promoted increases of 49.84% and 43.71%, respectively, in the efficiency of water use and carboxylation. The application of complex sources increased the stability of cell membranes, reducing electrolyte leakage, providing higher relative water content in seedlings irrigated with moderately saline water. From the results, we conclude that Ca-complex sources have potential as modulators of moderately saline water stress in sour passion fruit seedlings. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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24 pages, 5019 KiB

Open AccessArticle

Application Techniques and Concentrations of Ascorbic Acid to Reduce Saline Stress in Passion Fruit

by Edmilson Júnio Medeiros Caetano, André Alisson Rodrigues da Silva, Geovani Soares de Lima, Carlos Alberto Vieira de Azevedo, Luana Lucas de Sá Almeida Veloso, Thiago Filipe de Lima Arruda, Allesson Ramos de Souza, Lauriane Almeida dos Anjos Soares, Hans Raj Gheyi, Mirandy dos Santos Dias, Lucyelly Dâmela Araújo Borborema, Vitória Dantas de Sousa and Pedro Dantas Fernandes

Plants 2024, 13(19), 2718; https://doi.org/10.3390/plants13192718 - 28 Sep 2024

Viewed by 539

Abstract

Salinity restricts the growth of irrigated fruit crops in semi-arid areas, making it crucial to find ways to reduce salt stress. One effective strategy is using eliciting substances like ascorbic acid. In this context, the objective of this study was to evaluate the [...] Read more.

Salinity restricts the growth of irrigated fruit crops in semi-arid areas, making it crucial to find ways to reduce salt stress. One effective strategy is using eliciting substances like ascorbic acid. In this context, the objective of this study was to evaluate the effects of application methods and concentrations of ascorbic acid on the morphophysiology and production of sour passion fruit irrigated with saline water. The experiment was organized using a factorial randomized block design (3 × 3 × 2) with three application methods (soaking, spraying, and soaking and spraying), three concentrations of ascorbic acid (0, 0.8, and 1.6 mM) and two levels of electrical conductivity of irrigation water—ECw (0.8 and 3.8 dS m⁻¹). Foliar spraying of ascorbic acid at a concentration of 0.8 mM mitigated the effects of salt stress on the relative water content of leaves, the synthesis of photosynthetic pigments, gas exchange, and total production of sour passion fruit when irrigated with ECw of 3.8 dS m⁻¹. Plants grown with water of 0.8 dS m⁻¹ and under foliar application of 0.8 mM of ascorbic acid achieved the maximum growth in stem diameter and the greatest volume of pulp in the fruits. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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16 pages, 3384 KiB

Open AccessArticle

Impact of Nickel Toxicity on Growth, Fruit Quality and Antioxidant Response in Zucchini Squash (Cucurbita pepo L.)

by Oumayma Labidi, Rim Kouki, Saida Hidouri, Hana Bouzahouane, Isabel Caçador, Rosa M. Pérez-Clemente and Noomene Sleimi

Plants 2024, 13(17), 2361; https://doi.org/10.3390/plants13172361 - 24 Aug 2024

Viewed by 903

Abstract

The impact of trace metal elements (TMEs) on plants is one current pollution problem, the severity of which is increasing with industrial development, population growth and inappropriate agricultural practices. The latter can have irreversible effects on ecosystems, including species extinction, trophic chain contamination [...] Read more.

The impact of trace metal elements (TMEs) on plants is one current pollution problem, the severity of which is increasing with industrial development, population growth and inappropriate agricultural practices. The latter can have irreversible effects on ecosystems, including species extinction, trophic chain contamination and altered human health, particularly in the case of consumed plants such as zucchini squash (Cucurbita pepo L.). This study aims to investigate the effects of nickel on various physiological and biochemical parameters of zucchini growth, with a particular focus on how this toxic metal impacts the quality of fruit that is consumed by humans. To achieve this, plants aged 45 days were grown for one month on solid media loaded with different concentrations of Ni (0, 100, 300 and 500 µM). The results showed that exposure of plants to Ni resulted in significantly altered growth and higher accumulation of Ni in the shoots (1314 µg·g⁻¹ DW) than in roots and fruits. Concerning non-enzymatic antioxidants, the results showed that Ni toxicity significantly increased total polyphenols, especially in shoots at 300 µM Ni, while flavonoid content decreased in the roots and shoots in response to Ni treatment. Our results also show that nickel tolerance in C. pepo is ensured by a combination of several mechanisms such as an increase in the content of proline. This species can survive and tolerate, to different degrees, toxic cations at concentrations up to 500 µM but with visible symptoms of toxicity such as chlorosis of the leaves. Indeed, based on thresholds of hyperaccumulation, we can qualify Cucurbita pepo as a hyperaccumulator species of nickel. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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18 pages, 5987 KiB

Open AccessArticle

Postponed Application of Phosphorus and Potassium Fertilizers Mitigates the Damage of Late Spring Coldness by Improving Winter Wheat Root Physiology

by Hao Fang, Jinwei Huang, Xiatong Zhu, Muhammad Ahmad Hassan, Jin Ren, Jingyao Huang, Baoqiang Zheng, Xiang Chen, Feifei Lin and Jincai Li

Plants 2024, 13(16), 2311; https://doi.org/10.3390/plants13162311 - 20 Aug 2024

Cited by 1 | Viewed by 972

Abstract

Late spring coldness (LSC) is the main limiting factor threatening wheat yield and quality stability. Optimal nutrient management is beneficial in mitigating the harms of LSC by improving wheat root physiology. This study proposed a nutrient management strategy that postponed the application of [...] Read more.

Late spring coldness (LSC) is the main limiting factor threatening wheat yield and quality stability. Optimal nutrient management is beneficial in mitigating the harms of LSC by improving wheat root physiology. This study proposed a nutrient management strategy that postponed the application of phosphorus (P) and potassium (K), effectively strengthening wheat’s defense against LSC. This experiment used the winter cultivar “Yannong19” (YN 19) as plant material for two consecutive years (2021–2022 and 2022–2023). Two fertilizer treatments were used: traditional P and K fertilizers application (R1: base fertilizer: jointing fertilizer = 10:0) and postponed P and K fertilizers application (R2: base fertilizer: jointing fertilizer = 5:5); wheat plants at the anther connective formation stage shifted to temperature-controlled phytotrons for normal (T0, 11 °C/4 h) and low temperatures (T1, 4 °C/4 h; T2, −4 °C/4 h) as treatments of LSC. The results showed that under low temperature (LT) treatment, compared with R1, the R2 treatment increased the concentrations of osmotic adjustment substances (soluble sugars and soluble protein contents by 6.2–8.7% and 3.0–8.9%), enhanced activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase activities by 2.2–9.1%, 6.2–9.7% and 4.2–8.4%), balanced the hormone concentrations (increased IAA and GA₃ contents by 2.8–17.5% and 10.4–14.1% and decreased ABA contents by 7.2–14.3%), and reduced the toxicity (malondialdehyde, hydrogen peroxide content and O₂·⁻ production rate by 5.7–12.4%, 17.7–22.8% and 19.1–19.1%) of the cellular membranes. Furthermore, the wheat root physiology in R2 significantly improved as the root surface area and dry weight increased by 5.0–6.6% and 4.7–6.6%, and P and K accumulation increased by 7.4–11.3% and 12.2–15.4% compared to R1, respectively. Overall, the postponed application of P and K fertilizers enhanced the physiological function of the root system, maintained root morphology, and promoted the accumulation of wheat nutrients under the stress of LSC. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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18 pages, 10474 KiB

Open AccessArticle

Genome-Wide Identification and Molecular Evolutionary History of the Whirly Family Genes in Brassica napus

by Long Wang, Zhi Zhao, Huaxin Li, Damei Pei, Qianru Ma, Zhen Huang, Hongyan Wang and Lu Xiao

Plants 2024, 13(16), 2243; https://doi.org/10.3390/plants13162243 - 13 Aug 2024

Viewed by 887

Abstract

Whirly transcription factors are unique to plants, playing pivotal roles in managing leaf senescence and DNA repair. While present in various species, their identification in Brassica napus L. (B. napus) and their differences during hybridization and polyploidy has been elusive. [...] Read more.

Whirly transcription factors are unique to plants, playing pivotal roles in managing leaf senescence and DNA repair. While present in various species, their identification in Brassica napus L. (B. napus) and their differences during hybridization and polyploidy has been elusive. Addressing this, our study delves into the functional and evolutionary aspects of the Whirly gene family during the emergence of B. napus, applying bioinformatics and comparative genomics. We identified six Whirly genes in B. napus. In Brassica rapa L. (B. rapa), three Whirly genes were identified, while four were found in Brassica oleracea L. (B. oleracea). The results show that the identified Whirly genes not only have homology but also share the same chromosomal positions. Phylogenetic analysis indicates that Whirly genes in monocots and dicots exhibit high conservation. In the evolutionary process, the Whirly gene family in B. napus experienced events of intron/exon loss. Collinearity insights point to intense purifying selection post-duplication. Promoter regions housed diverse cis-acting elements linked to photoresponse, anaerobic initiation, and methyl jasmonate responsiveness. Notably, elements tied to abscisic acid signaling and meristem expression were prominent in diploid ancestors but subdued in tetraploid B. napus. Tissue-specific expression unveiled analogous patterns within subfamily genes. Subsequent qRT-PCR analysis spotlighted BnAWHY1b’s potential significance in abiotic stress response, particularly drought. These findings can be used as theoretical foundations to understand the functions and effects of the Whirly gene family in B. napus, providing references for the molecular mechanism of gene evolution between this species and its diploid ancestors. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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24 pages, 5001 KiB

Open AccessArticle

Fish Waste—A Novel Bio-Fertilizer for Stevia (Stevia rebaudiana Bertoni) under Salinity-Induced Stress

by Zahra Mahdavi, Behrouz Esmailpour, Rasul Azarmi, Sima Panahirad, Georgia Ntatsi, Gholamreza Gohari and Vasileios Fotopoulos

Plants 2024, 13(14), 1909; https://doi.org/10.3390/plants13141909 - 11 Jul 2024

Viewed by 1284

Abstract

Currently, different strategies, including the application of bio-fertilizers, are used to ameliorate the adverse effects posed by salinity stress as the major global problem in plants. Fish waste is suggested as a novel bio-fertilizer to mitigate the effects of biotic and abiotic stresses. [...] Read more.

Currently, different strategies, including the application of bio-fertilizers, are used to ameliorate the adverse effects posed by salinity stress as the major global problem in plants. Fish waste is suggested as a novel bio-fertilizer to mitigate the effects of biotic and abiotic stresses. In this investigation, an experiment was conducted to investigate the effects by applying different concentrations (0, 5, 10, and 15% (v/v)) of fish waste bio-fertilizer on stevia plants grown under salt stress conditions (0, 20, 40, and 60 mM of NaCl). Results showed that salinity negatively affected growth parameters, the photosynthetic pigments, the relative water content, and the chlorophyll fluorescence parameters while increased the activity of antioxidant enzymes, total phenol, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), proline, and total carbohydrates compared with control samples. On the other hand, the application of fish waste bio-fertilizer mitigated the effects of salinity stress by enhancing growth and mitigating stress-relative markers, especially at the highest salinity level (60 mM). Overall, fish waste bio-fertilizer could be considered a sustainable, innovative approach for the alleviation of salinity stress effects in plants and, in addition, fish waste bio-fertilizer did not cause more salinity issues, at least with the applied doses and experiment time, which is an imperative aspect. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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23 pages, 2225 KiB

Open AccessArticle

Exogenous Sodium Nitroprusside Affects the Redox System of Wheat Roots Differentially Regulating the Activity of Antioxidant Enzymes under Short-Time Osmotic Stress

by Alsu Lubyanova and Chulpan Allagulova

Plants 2024, 13(14), 1895; https://doi.org/10.3390/plants13141895 - 9 Jul 2024

Viewed by 746

Abstract

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity [...] Read more.

Nitric oxide (NO) is a multifunctional signalling molecule involved in the regulation of plant ontogenesis and adaptation to different adverse environmental factors, in particular to osmotic stress. Understanding NO-induced plant protection is important for the improvement of plant stress tolerance and crop productivity under global climate changes. The root system is crucial for plant survival in a changeable environment. Damages that it experiences under water deficit conditions during the initial developmental periods seriously affect the viability of the plants. This work was devoted to the comparative analysis of the pretreatment of wheat seedlings through the root system with NO donor sodium nitroprusside (SNP) for 24 h on various parameters of redox homeostasis under exposure to osmotic stress (PEG 6000, 12%) over 0.5–24 h. The active and exhausted solutions of SNP, termed as (SNP/+NO) and (SNP/−NO), respectively, were used in this work at a concentration of 2 × 10⁻⁴ M. Using biochemistry and light microscopy methods, it has been revealed that osmotic stress caused oxidative damages and the disruption of membrane cell structures in wheat roots. PEG exposure increased the production of superoxide (O₂^•−), hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and the levels of electrolyte leakage (EL) and lipid peroxidation (LPO). Stress treatment enhanced the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), the excretion of proline, and the rate of cell death and inhibited their division. Pretreatment with (SNP/+NO) decreased PEG-induced root damages by differently regulating the antioxidant enzymes under stress conditions. Thus, (SNP/+NO) pretreatment led to SOD, APX, and CAT inhibition during the first 4 h of stress and stimulated their activity after 24 h of PEG exposure when compared to SNP-untreated or (SNP/−NO)-pretreated and stress-subjected plants. Osmotic stress triggered the intense excretion of proline by roots into the external medium. Pretreatment with (SNP/+NO) in contrast with (SNP/−NO) additionally increased stress-induced proline excretion. Our results indicate that NO is able to mitigate the destructive effects of osmotic stress on the roots of wheat seedlings. However, the mechanisms of NO protective action may be different at certain periods of stress exposure. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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24 pages, 12478 KiB

Open AccessArticle

Use of Proline to Induce Salt Stress Tolerance in Guava

by Smyth Trotsk de Araújo Silva, Geovani Soares de Lima, Vera Lúcia Antunes de Lima, Jackson Silva Nóbrega, Saulo Soares da Silva, Jean Telvio Andrade Ferreira, Maila Vieira Dantas, Iara Almeida Roque, Lauriane Almeida dos Anjos Soares, Rafaela Aparecida Frazão Torres, Cassiano Nogueira de Lacerda, Hans Raj Gheyi, Luderlândio de Andrade Silva and Valéria Fernandes de Oliveira Sousa

Plants 2024, 13(14), 1887; https://doi.org/10.3390/plants13141887 - 9 Jul 2024

Viewed by 889

Abstract

Guava is a fruit tree with high potential in the semi-arid region of northeast Brazil. However, qualitative and quantitative water scarcity is a limiting factor for the expansion of irrigated agriculture. Thus, it is necessary to use techniques to mitigate the effects of [...] Read more.

Guava is a fruit tree with high potential in the semi-arid region of northeast Brazil. However, qualitative and quantitative water scarcity is a limiting factor for the expansion of irrigated agriculture. Thus, it is necessary to use techniques to mitigate the effects of salt stress, such as foliar application of proline. The objective of this study was to evaluate the effect of foliar application of proline as a mitigator of salt stress effects on the morphophysiology of guava cv. Paluma. The experiment was carried out under field conditions at the ‘Rolando Enrique Rivas Castellón’ Experimental Farm in São Domingos, PB, Brazil, using a randomized block design in a 5 × 4 factorial scheme referring to five levels of electrical conductivity of irrigation water, ECw (0.8, 1.5, 2.2, 2.9, and 3.5 dS m⁻¹) and four concentrations of proline (0, 8, 16, and 24 mM). Salinity above 0.8 dS m⁻¹ compromised gas exchange, photosynthetic pigment synthesis, photochemical efficiency, and growth of guava plants at 360 days after transplanting. Foliar application of proline at a concentration of 24 mM mitigated the effect of salt stress on the relative water content, stomatal conductance, and carotenoid contents in plants irrigated with 3.6 dS m⁻¹ water. Meanwhile, a proline concentration of up to 18 mM resulted in higher transpiration, CO₂ assimilation rate, instantaneous carboxylation efficiency, and absolute growth rate in stem diameter under ECw of 0.8 dS m⁻¹. Proline concentration of up to 24 mM increased the biosynthesis of photosynthetic pigments and the relative growth rate in stem diameter of guava in the period from 190 to 360 days after transplanting. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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23 pages, 3703 KiB

Open AccessArticle

High Concentrations of Se Inhibited the Growth of Rice Seedlings

by Ying Liu, Jiayu Ma, Feng Li, Xiang Zeng, Zhengwei Wu, Yongxiang Huang, Yingbin Xue and Yanyan Wang

Plants 2024, 13(11), 1580; https://doi.org/10.3390/plants13111580 - 6 Jun 2024

Viewed by 1104

Abstract

Selenium (Se) is crucial for both plants and humans, with plants acting as the main source for human Se intake. In plants, moderate Se enhances growth and increases stress resistance, whereas excessive Se leads to toxicity. The physiological mechanisms by which Se influences [...] Read more.

Selenium (Se) is crucial for both plants and humans, with plants acting as the main source for human Se intake. In plants, moderate Se enhances growth and increases stress resistance, whereas excessive Se leads to toxicity. The physiological mechanisms by which Se influences rice seedlings’ growth are poorly understood and require additional research. In order to study the effects of selenium stress on rice seedlings, plant phenotype analysis, root scanning, metal ion content determination, physiological response index determination, hormone level determination, quantitative PCR (qPCR), and other methods were used. Our findings indicated that sodium selenite had dual effects on rice seedling growth under hydroponic conditions. At low concentrations, Se treatment promotes rice seedling growth by enhancing biomass, root length, and antioxidant capacity. Conversely, high concentrations of sodium selenite impair and damage rice, as evidenced by leaf yellowing, reduced chlorophyll content, decreased biomass, and stunted growth. Elevated Se levels also significantly affect antioxidase activities and the levels of proline, malondialdehyde, metal ions, and various phytohormones and selenium metabolism, ion transport, and antioxidant genes in rice. The adverse effects of high Se concentrations may directly disrupt protein synthesis or indirectly induce oxidative stress by altering the absorption and synthesis of other compounds. This study aims to elucidate the physiological responses of rice to Se toxicity stress and lay the groundwork for the development of Se-enriched rice varieties. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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12 pages, 2635 KiB

Open AccessArticle

Growth, Productivity, Yield Components and Seasonality of Different Genotypes of Forage Clover Lotus corniculatus L. under Varied Soil Moisture Contents

by Sahara Xolocotzi-Acoltzi, Aurelio Pedroza-Sandoval, Gabino García-De los Santos, Perpetuo Álvarez-Vázquez and Isaac Gramillo-Ávila

Plants 2024, 13(10), 1407; https://doi.org/10.3390/plants13101407 - 18 May 2024

Viewed by 1128

Abstract

This study aimed to evaluate the response to water deficit of different ecotypes and a variety of Lotus corniculatus on growth, productivity, and yield components, through seasonal times. A randomized block experimental design in a 2 × 5 factorial arrangement with three replicates [...] Read more.

This study aimed to evaluate the response to water deficit of different ecotypes and a variety of Lotus corniculatus on growth, productivity, and yield components, through seasonal times. A randomized block experimental design in a 2 × 5 factorial arrangement with three replicates was used. The first variation factor was soil moisture contents: field capacity (FC) was 26.5% ± 1.5, and water deficit (WD) was 85% of FC (22.5% ± 1.5); the second variation factor was the ecotypes identified with the codes 255301, 255305, 202700 and 226792 and of the variety Estanzuela Ganador. The best responses in plant cover and weight of accumulated fresh biomass were obtained in the ecotype 202700 under WD, with values of 1649.0 cm² and 583.7 g plant⁻¹, and 1661.2 cm² and 740.1 g plant⁻¹ in ecotype 255305 under FC. The leaf clover was the main component of yield during the summer and autumn seasons. Ecotype 226792 was tolerant to low temperatures during the winter season with better leaf development. Ecotype 202700 is the best option for forage clover production when water is limited, and ecotype 255305 when water is not resource-limited, but these preliminary conclusions need to be confirmed in field studies. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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27 pages, 2480 KiB

Open AccessArticle

Isolation and Characterization of Plant-Growth-Promoting, Drought-Tolerant Rhizobacteria for Improved Maize Productivity

by Victor Funso Agunbiade, Ayomide Emmanuel Fadiji, Nadège Adoukè Agbodjato and Olubukola Oluranti Babalola

Plants 2024, 13(10), 1298; https://doi.org/10.3390/plants13101298 - 8 May 2024

Cited by 5 | Viewed by 2309

Abstract

Drought is one of the main abiotic factors affecting global agricultural productivity. However, the application of bioinocula containing plant-growth-promoting rhizobacteria (PGPR) has been seen as a potential environmentally friendly technology for increasing plants’ resistance to water stress. In this study, rhizobacteria strains were [...] Read more.

Drought is one of the main abiotic factors affecting global agricultural productivity. However, the application of bioinocula containing plant-growth-promoting rhizobacteria (PGPR) has been seen as a potential environmentally friendly technology for increasing plants’ resistance to water stress. In this study, rhizobacteria strains were isolated from maize (Zea mays L.) and subjected to drought tolerance tests at varying concentrations using polyethylene glycol (PEG)-8000 and screened for plant-growth-promoting activities. From this study, 11 bacterial isolates were characterized and identified molecularly, which include Bacillus licheniformis A5-1, Aeromonas caviae A1-2, A. veronii C7_8, B. cereus B8-3, P. endophytica A10-11, B. halotolerans A9-10, B. licheniformis B9-5, B. simplex B15-6, Priestia flexa B12-4, Priestia flexa C6-7, and Priestia aryabhattai C1-9. All isolates were positive for indole-3-acetic acid (IAA), siderophore, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, ammonia production, nitrogen fixation, and phosphate solubilization, but negative for hydrogen cyanide production. Aeromonas strains A1-2 and C7_8, showing the highest drought tolerance of 0.71 and 0.77, respectively, were selected for bioinoculation, singularly and combined. An increase in the above- and below-ground biomass of the maize plants at 100, 50, and 25% water-holding capacity (WHC) was recorded. Bacterial inoculants, which showed an increase in the aerial biomass of plants subjected to moderate water deficiency by up to 89%, suggested that they can be suitable candidates to enhance drought tolerance and nutrient acquisition and mitigate the impacts of water stress on plants. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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15 pages, 6621 KiB

Open AccessArticle

Effect of Secondary Paper Sludge on Physiological Traits of Lactuca sativa L. under Heavy-Metal Stress

by Marija Yurkevich, Arkadiy Kurbatov and Elena Ikkonen

Plants 2024, 13(8), 1098; https://doi.org/10.3390/plants13081098 - 14 Apr 2024

Cited by 1 | Viewed by 974

Abstract

To eliminate the negative effect of soil contamination with heavy metals on plant growth and crop yield, different methods and techniques are the subject of discussion and study. In this study, we aimed to evaluate the effect of secondary pulp and paper-mill sludge [...] Read more.

To eliminate the negative effect of soil contamination with heavy metals on plant growth and crop yield, different methods and techniques are the subject of discussion and study. In this study, we aimed to evaluate the effect of secondary pulp and paper-mill sludge application to soil on the response of the main physiological processes such as the growth, photosynthesis, and respiration of lettuce (Lactuca sativa L.) plants to soil contamination with Pb. For the pot experiment, Pb was added to sandy loam soil at concentrations of 0, 50, and 250 mg Pb(NO₃)₂ per kg of the soil, and secondary sludge was added to a 0, 20, or 40% sludge solution during each plant watering. The Pb-mediated change in plant biomass allocation, decrease in the photosynthetic rate, increase in leaf respiration rate, and the degree of light inhibition of respiration were closely associated with increases in both root and shoot Pb content. For the Pb-free soil condition, secondary sludge application contributed to the allocation of plant biomass towards a greater accumulation in the shoots than in the roots. Although stomatal opening was not affected by either Pb or sludge, sludge application increased photosynthetic CO₂ assimilation regardless of soil Pb content, which was associated with an increase in the electron-transport rate and carboxylase activity of Rubisco. Soil contamination with Pb significantly increased the ratio of respiration to photosynthesis, reflecting a shift in the carbon balance toward carbon losses in the leaves, but sludge application modified the coupling between the processes with a decrease in the proportion of respiratory carbon losses. The sludge-mediated recovery of the physiological processes of L. sativa reflected an increase in plant tolerance to soil contamination with heavy metals, the formation of which is associated with plant and soil adjustments initiated by secondary sludge application. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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13 pages, 7358 KiB

Open AccessArticle

The Physiological Response of Apricot Flowers to Low-Temperature Stress

by Jingjing Gao, Wenbo Guo, Qingwei Liu, Meige Liu, Chen Shang, Yuqin Song, Ruijie Hao, Liulin Li and Xinxin Feng

Plants 2024, 13(7), 1002; https://doi.org/10.3390/plants13071002 - 31 Mar 2024

Cited by 1 | Viewed by 1578

Abstract

The growth and development of apricot flower organs are severely impacted by spring frosts. To better understand this process, apricot flowers were exposed to temperatures ranging from 0 °C to −8 °C, including a control at 18 °C, in artificial incubators to mimic [...] Read more.

The growth and development of apricot flower organs are severely impacted by spring frosts. To better understand this process, apricot flowers were exposed to temperatures ranging from 0 °C to −8 °C, including a control at 18 °C, in artificial incubators to mimic diverse low-temperature environments. We aimed to examine their physiological reactions to cold stress, with an emphasis on changes in phenotype, membrane stability, osmotic substance levels, and antioxidant enzyme performance. Results reveal that cold stress induces significant browning and cellular damage, with a sharp increase in browning rate and membrane permeability below −5 °C. Soluble sugars and proteins initially rise as osmoprotectants, but their content decreases at lower temperatures. Proline content consistently increases, suggesting a protective role. Antioxidant enzyme activities, including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX), exhibit a complex pattern, with initial increases followed by declines at more severe cold conditions. Correlation and principal component analyses highlight the interplay between these responses, indicating a multifaceted adaptation strategy. The findings contribute to the understanding of apricot cold tolerance and inform breeding efforts for improved crop resilience. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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20 pages, 6376 KiB

Open AccessArticle

Ability of Different Growth Indicators to Detect Salt Tolerance of Advanced Spring Wheat Lines Grown in Real Field Conditions

by Muhammad Mubushar, Salah El-Hendawy, Yaser Hassan Dewir and Nasser Al-Suhaibani

Plants 2024, 13(6), 882; https://doi.org/10.3390/plants13060882 - 19 Mar 2024

Viewed by 1358

Abstract

Plant growth indicators (GIs) are important for evaluating how different genotypes respond to normal and stress conditions separately. They consider both the morphological and physiological components of plants between two successive growth stages. Despite their significance, GIs are not commonly used as screening [...] Read more.

Plant growth indicators (GIs) are important for evaluating how different genotypes respond to normal and stress conditions separately. They consider both the morphological and physiological components of plants between two successive growth stages. Despite their significance, GIs are not commonly used as screening criteria for detecting salt tolerance of genotypes. In this study, 36 recombinant inbred lines (RILs) along with four genotypes differing in their salt tolerance were grown under normal and 150 mM NaCl in a two-year field trial. The performance and salt tolerance of these germplasms were assessed through various GIs. The analysis of variance showed highly significant variation between salinity levels, genotypes, and their interaction for all GIs and other traits in each year and combined data for two years, with a few exceptions. All traits and GIs were significantly reduced by salinity stress, except for relative growth rate (RGR), net assimilation rate (NAR), and specific leaf weight (SLW), which increased under salinity conditions. Traits and GIs were more correlated with each other under salinity than under normal conditions. Principal component analysis organized traits and GIs into three main groups under both conditions, with RGR, NAR, and specific leaf area (SLA) closely associated with grain yield (GY) and harvest index, while leaf area duration (LAD) was closely associated with green leaf area (GLA), plant dry weight (PDW), and leaf area index (LAI). A hierarchical clustering heatmap based on GIs and traits organized germplasms into three and four groups under normal and salinity conditions, respectively. Based on the values of traits and GIs for each group, the germplasms varied from high- to low-performing groups under normal conditions and from salt-tolerant to salt-sensitive groups under salinity conditions. RGR, NAR, and LAD were important factors determining genotypic variation in GY of high- and low-performing groups, while all GIs, except leaf area duration (LAR), were major factors describing genotypic variation in GY of salt-tolerant and salt-sensitive groups. In conclusion, different GIs that reveal the relationship between the morphological and physiological components of genotypes could serve as valuable selection criteria for evaluating the performance of genotypes under normal conditions and their salt tolerance under salinity stress conditions. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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17 pages, 10597 KiB

Open AccessArticle

Transcriptome Profiling of a Salt Excluder Hybrid Grapevine Rootstock ‘Ruggeri’ throughout Salinity

by Pranavkumar Gajjar, Ahmed Ismail, Tabibul Islam, Md Moniruzzaman, Ahmed G. Darwish, Ahmed S. Dawood, Ahmed G. Mohamed, Amr M. Haikal, Abdelkareem M. El-Saady, Ashraf El-Kereamy, Sherif M. Sherif, Michael D. Abazinge, Devaiah Kambiranda and Islam El-Sharkawy

Plants 2024, 13(6), 837; https://doi.org/10.3390/plants13060837 - 14 Mar 2024

Viewed by 1303

Abstract

Salinity is one of the substantial threats to plant productivity and could be escorted by other stresses such as heat and drought. It impairs critical biological processes, such as photosynthesis, energy, and water/nutrient acquisition, ultimately leading to cell death when stress intensity becomes [...] Read more.

Salinity is one of the substantial threats to plant productivity and could be escorted by other stresses such as heat and drought. It impairs critical biological processes, such as photosynthesis, energy, and water/nutrient acquisition, ultimately leading to cell death when stress intensity becomes uncured. Therefore, plants deploy several proper processes to overcome such hostile circumstances. Grapevine is one of the most important crops worldwide that is relatively salt-tolerant and preferentially cultivated in hot and semi-arid areas. One of the most applicable strategies for sustainable viticulture is using salt-tolerant rootstock such as Ruggeri (RUG). The rootstock showed efficient capacity of photosynthesis, ROS detoxification, and carbohydrate accumulation under salinity. The current study utilized the transcriptome profiling approach to identify the molecular events of RUG throughout a regime of salt stress followed by a recovery procedure. The data showed progressive changes in the transcriptome profiling throughout salinity, underpinning the involvement of a large number of genes in transcriptional reprogramming during stress. Our results established a considerable enrichment of the biological process GO-terms related to salinity adaptation, such as signaling, hormones, photosynthesis, carbohydrates, and ROS homeostasis. Among the battery of molecular/cellular responses launched upon salinity, ROS homeostasis plays the central role of salt adaptation. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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14 pages, 2055 KiB

Open AccessArticle

Interactive Effects of Temperature, Water Regime, and [CO₂] on Wheats with Different Heat Susceptibilities

by Rong Zhou, Benita Hyldgaard, Lamis Abdelhakim, Thayna Mendanha, Steven Driever, Davide Cammarano, Eva Rosenqvist and Carl-Otto Ottosen

Plants 2024, 13(6), 830; https://doi.org/10.3390/plants13060830 - 13 Mar 2024

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Abstract

Plants’ response to single environmental changes can be highly distinct from the response to multiple changes. The effects of a single environmental factor on wheat growth have been well documented. However, the interactive influences of multiple factors on different wheat genotypes need further [...] Read more.

Plants’ response to single environmental changes can be highly distinct from the response to multiple changes. The effects of a single environmental factor on wheat growth have been well documented. However, the interactive influences of multiple factors on different wheat genotypes need further investigation. Here, treatments of three important growth factors, namely water regime, temperature, and CO₂ concentration ([CO₂]), were applied to compare the response of two wheat genotypes with different heat sensitivities. The temperature response curves showed that both genotypes showed more variations at elevated [CO₂] (e[CO₂]) than ambient [CO₂] (a[CO₂]) when the plants were treated under different water regimes and temperatures. This corresponded to the results of water use efficiency at the leaf level. At e[CO₂], heat-tolerant ‘Gladius’ showed a higher net photosynthetic rate (P_n), while heat-susceptible ‘Paragon’ had a lower P_n at reduced water, as compared with full water availability. The temperature optimum for photosynthesis in wheat was increased when the growth temperature was high, while the leaf carbon/nitrogen was increased via a reduced water regime. Generally, water regime, temperature and [CO₂] have significant interactive effects on both wheat genotypes. Two wheat genotypes showed different physiological responses to different combinations of environmental factors. Our investigation concerning the interactions of multi-environmental factors on wheat will benefit the future wheat climate-response study. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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18 pages, 6173 KiB

Open AccessArticle

Comparison of Growth and Physiological Effects of Soil Moisture Regime on Plantago maritima Plants from Geographically Isolated Sites on the Eastern Coast of the Baltic Sea

by Katrīna Anna Ozoliņa, Astra Jēkabsone, Una Andersone-Ozola and Gederts Ievinsh

Plants 2024, 13(5), 633; https://doi.org/10.3390/plants13050633 - 25 Feb 2024

Cited by 1 | Viewed by 1666

Abstract

The aim of the present study was to evaluate the morphological and physiological responses of P. maritima plants from five geographically isolated sites growing in habitats with different conditions to different substrate moisture levels in controlled conditions. Plants were produced from seed and [...] Read more.

The aim of the present study was to evaluate the morphological and physiological responses of P. maritima plants from five geographically isolated sites growing in habitats with different conditions to different substrate moisture levels in controlled conditions. Plants were produced from seed and cultivated in a greenhouse at four relatively constant soil moisture regimes: at 25, 50, and 75% soil water content and in soil flooded 3 cm above the surface (80% F). The two morphological traits that varied most strikingly among P. maritima accessions were the number of flower stalks and the number of leaves. Only plants from two accessions uniformly produced generative structures, and allocation to flowering was suppressed by both low moisture and flooding. Optimum shoot biomass accumulation for all accessions was at 50 and 75% soil moisture. The Performance Index Total was the most sensitive among the measured photosynthesis-related parameters, and it tended to decrease with an increase in soil water content for all P. maritima accessions. The initial hypothesis—that plants from relatively dry habitats will have a higher tolerance against low soil water levels, but plants from relatively wet habitats will have a higher tolerance against waterlogged or flooded soil—was not proven. The existence of three ecotypes of P. maritima within the five accessions from geographically isolated subpopulations on the eastern coast of the Baltic Sea at the level of morphological responses to soil water content can be proposed. P. maritima plants can be characterized as extremely tolerant to soil waterlogging and highly tolerant to soil flooding and low soil water content. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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25 pages, 20094 KiB

Open AccessArticle

Synergistic Influence of Arbuscular mycorrhizal Fungi Inoculation with Nanoparticle Foliar Application Enhances Chili (Capsicum annuum L.) Antioxidant Enzymes, Anatomical Characteristics, and Productivity under Cold-Stress Conditions

by Eman G. Sayed, S. F. Desoukey, Abeer F. Desouky, Mervat F. Farag, Ragab I. EL-kholy and Samah N. Azoz

Plants 2024, 13(4), 517; https://doi.org/10.3390/plants13040517 - 14 Feb 2024

Cited by 3 | Viewed by 1666

Abstract

In this study, we aimed to evaluate the effects of Arbuscular mycorrhiza fungus (AMF) inoculation, foliar application of zinc oxide and selenium nanoparticles (ZnO-NPs and Se-NPs), and their combined interactions on the growth and productivity of chili pepper under cold-stress conditions. Two field [...] Read more.

In this study, we aimed to evaluate the effects of Arbuscular mycorrhiza fungus (AMF) inoculation, foliar application of zinc oxide and selenium nanoparticles (ZnO-NPs and Se-NPs), and their combined interactions on the growth and productivity of chili pepper under cold-stress conditions. Two field experiments were successfully conducted during the winter seasons of 2021 and 2022 in an experimental field at the Faculty of Agriculture, Cairo University, Giza, Egypt. The results showed that, under cold stress, the combination of AMF inoculation and ZnO-NPs + Se-NPs as a foliar spray increased the average fruit weight by 92.4% and 98.7%, and the number of fruits by 34.6% and 54.8 compared to control treatment in the 2021 and 2022 seasons, respectively. Additionally, the combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) significantly increased the total marketable yield by 95.8% and 94.7% compared to the control, which recorded values of 2.4 and 1.9 kg m⁻² in the 2021 and 2022 seasons, respectively. Furthermore, the combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) showed the highest total content of ascorbic acid and capsaicin in chili fruits compared to the other treatments. The combination of AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) stimulated the accumulation of peroxidase (POD) and nitrogen glutamate dehydrogenase (GDH) while decreasing hydrogen peroxide (H₂O₂) and lipid peroxidation (MDA) contents. SDS analysis revealed that the application of ZnO-NPs, Se-NPs, AMF + ZnO-NPs, and AMF + ZnO-NPs + Se-NPs induced the emergence of new protein bands and reconstitution of those damaged by cold stress. Regarding histological structure, the combination of AMF inoculation and ZnO-NPs + Se-NPs as a foliar spray showed an enhancement in the thickness of grana thylakoids and increased the number of chloroplasts. Intriguingly, the findings showed that AMF and a mixture of nanoparticles (ZnO-NPs + Se-NPs) could offer guidance for increasing plant development and productivity under cold-stress conditions. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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16 pages, 2622 KiB

Open AccessArticle

Beneficial Effect of Exogenously Applied Calcium Pyruvate in Alleviating Water Deficit in Sugarcane as Assessed by Chlorophyll a Fluorescence Technique

by Mirandy dos Santos Dias, Francisco de Assis da Silva, Pedro Dantas Fernandes, Carlos Henrique de Azevedo Farias, Robson Felipe de Lima, Maria de Fátima Caetano da Silva, Vitória Régia do Nascimento Lima, Andrezza Maia de Lima, Cassiano Nogueira de Lacerda, Lígia Sampaio Reis, Weslley Bruno Belo de Souza, André Alisson Rodrigues da Silva and Thiago Filipe de Lima Arruda

Plants 2024, 13(3), 434; https://doi.org/10.3390/plants13030434 - 1 Feb 2024

Cited by 1 | Viewed by 1220

Abstract

The growing demand for food production has led to an increase in agricultural areas, including many with low and irregular rainfall, stressing the importance of studies aimed at mitigating the harmful effects of water stress. From this perspective, the objective of this study [...] Read more.

The growing demand for food production has led to an increase in agricultural areas, including many with low and irregular rainfall, stressing the importance of studies aimed at mitigating the harmful effects of water stress. From this perspective, the objective of this study was to evaluate calcium pyruvate as an attenuator of water deficit on chlorophyll a fluorescence of five sugarcane genotypes. The experiment was conducted in a plant nursery where three management strategies (E1—full irrigation, E2—water deficit with the application of 30 mM calcium pyruvate, and E3—water deficit without the application of calcium pyruvate) and five sugarcane genotypes (RB863129, RB92579, RB962962, RB021754, and RB041443) were tested, distributed in randomized blocks, in a 3 × 5 factorial design with three replications. There is dissimilarity in the fluorescence parameters and photosynthetic pigments of the RB863129 genotype in relation to those of the RB041443, RB96262, RB021754, and RB92579 genotypes. Foliar application of calcium pyruvate alleviates the effects of water deficit on the fluorescence parameters of chlorophyll a and photosynthetic pigments in sugarcane, without interaction with the genotypes. However, subsequent validation tests will be necessary to test and validate the adoption of this technology under field conditions. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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18 pages, 2795 KiB

Open AccessArticle

Water-Retaining Polymer and Planting Pit Size on Chlorophyll Index, Gas Exchange and Yield of Sour Passion Fruit with Deficit Irrigation

by Antônio Gustavo de Luna Souto, Edinete Nunes de Melo, Lourival Ferreira Cavalcante, Ana Paula Pereira do Nascimento, Ítalo Herbert Lucena Cavalcante, Geovani Soares de Lima, Rafael Oliveira Batista, Hans Raj Gheyi, Reynaldo Teodoro de Fátima, Evandro Franklin de Mesquita, Gleyse Lopes Fernandes de Souza, Guilherme Romão Silva, Daniel Valadão Silva, Francisco de Oliveira Mesquita and Palloma Vitória Carlos de Oliveira

Plants 2024, 13(2), 235; https://doi.org/10.3390/plants13020235 - 15 Jan 2024

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Abstract

Water availability is a limiting factor for the cultivation of sour passion fruit. Soil management techniques and the use of water-retaining polymers can increase soil water retention, reducing the frequency of irrigation in the crop. In this context, the objective of the research [...] Read more.

Water availability is a limiting factor for the cultivation of sour passion fruit. Soil management techniques and the use of water-retaining polymers can increase soil water retention, reducing the frequency of irrigation in the crop. In this context, the objective of the research was to evaluate the gas exchange, the chlorophyll index, and the yield of the sour passion fruit cv. BRS GA1 as a function of irrigation depths, pit volumes, and doses of water-retaining polymer. The experiment was carried out in randomized blocks, in plots subdivided in a 2 × (2 × 5) arrangement, with irrigation depths of 70 and 100% of the crop evapotranspiration (ETc) as the main plot, the subplots with the volumes of pit of 64 and 128 dm³, and doses of the water-retaining polymer of 0, 0.5, 1.0, 1.5, and 2.0 g dm⁻³. The interaction of irrigation depths × pit volumes × doses of water-retaining polymer influences chlorophyll indexes, gas exchange, and water productivity, with positive impacts on yield of the sour passion fruit. The water depth of 70% of ETc increased the yield of sour passion fruit, in pits of 64 dm³. The application of doses of up to 1.1 g dm⁻³ of the water-retaining polymer and irrigation with water of 70% of ETc is recommended, and a dose of 2.0 g dm⁻³ of the water-retaining polymer in a pit volume of 128 dm³, associated with an irrigation depth of 100% ETc causes stress in sour passion fruit plants due to excess water. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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16 pages, 1649 KiB

Open AccessArticle

Exploring the Differential Impact of Salt Stress on Root Colonization Adaptation Mechanisms in Plant Growth-Promoting Rhizobacteria

by Lorena del Rosario Cappellari, Pablo Cesar Bogino, Fiorela Nievas, Walter Giordano and Erika Banchio

Plants 2023, 12(23), 4059; https://doi.org/10.3390/plants12234059 - 3 Dec 2023

Cited by 2 | Viewed by 2065

Abstract

Salinity inhibits plant growth by affecting physiological processes, but soil microorganisms like plant growth-promoting rhizobacteria (PGPR) can alleviate abiotic stress and enhance crop productivity. However, it should be noted that rhizobacteria employ different approaches to deal with salt stress conditions and successfully colonize [...] Read more.

Salinity inhibits plant growth by affecting physiological processes, but soil microorganisms like plant growth-promoting rhizobacteria (PGPR) can alleviate abiotic stress and enhance crop productivity. However, it should be noted that rhizobacteria employ different approaches to deal with salt stress conditions and successfully colonize roots. The objective of this study was to investigate the effect of salt stress on bacterial survival mechanisms such as mobility, biofilm formation, and the autoaggregation capacity of three plant growth-promoting strains: Pseudomonas putida SJ04, Pseudomonas simiae WCS417r, and Bacillus amyloliquefaciens GB03. These strains were grown in diluted LB medium supplemented with 0, 100, 200, or 300 mM NaCl. Swimming and swarming mobility were evaluated in media supplemented with 0.3 and 0.5% agar, respectively. Biofilm formation capacity was quantified using the crystal violet method, and the autoaggregation capacity was measured spectrophotometrically. In addition, we evaluated in vitro the capacity of the strains to ameliorate the effects of saline stress in Mentha piperita. The study found that the GB03 strain exhibited enhanced swarming mobility when the salt concentration in the medium increased, resulting in a two-fold increase in the halo diameter at 300 mM. However, high concentrations of NaCl did not affect the swimming mobility. In contrast, swimming motility was reduced in WCS417r and SJ04 under salt stress. On the other hand, exposure to 300 mM NaCl resulted in a 180% increase in biofilm formation and a 30% rise in the percentage of autoaggregation in WCS417r. Conversely, the autoaggregation percentage of the strains SJ04 and GB03 remained unaffected by saline stress. However, for GB03, biofilm formation decreased by 80% at 300 mM. Simultaneously, inoculation with the three evaluated strains alleviated the detrimental effects of salinity on plant growth. Under 150 mM salt stress, all strains showed increased fresh weight, with GB03 and WCS417r improving by 40% and SJ04 exhibiting the most remarkable effect with a 70% rise compared to non-inoculated plants. Despite their different strategies for mitigating salt stress, the application of these strains presents a promising strategy for effectively mitigating the negative consequences of salt stress on plant cultivation. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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17 pages, 2082 KiB

Open AccessArticle

The Effects of Irrigation Water Salinity on the Synthesis of Photosynthetic Pigments, Gas Exchange, and Photochemical Efficiency of Sour Passion Fruit Genotypes

by Francisco Jean da Silva Paiva, Geovani Soares de Lima, Vera Lúcia Antunes de Lima, Weslley Bruno Belo de Souza, Lauriane Almeida dos Anjos Soares, Rafaela Aparecida Frazão Torres, Hans Raj Gheyi, Luderlândio de Andrade Silva, Francisco Vanies da Silva Sá, Valeska Karolini Nunes Oliveira de Sá, Smyth Trotsk de Araújo Silva, Reynaldo Teodoro de Fátima, Pedro Dantas Fernandes and Alan Keis Chaves de Almeida

Plants 2023, 12(22), 3894; https://doi.org/10.3390/plants12223894 - 18 Nov 2023

Cited by 2 | Viewed by 1497

Abstract

The objective of this study was to evaluate the synthesis of photosynthetic pigments, gas exchange, and photochemical efficiency of sour passion fruit genotypes irrigated with saline water under the conditions of the semi-arid region of Paraíba state, Brazil. The experiment was conducted at [...] Read more.

The objective of this study was to evaluate the synthesis of photosynthetic pigments, gas exchange, and photochemical efficiency of sour passion fruit genotypes irrigated with saline water under the conditions of the semi-arid region of Paraíba state, Brazil. The experiment was conducted at the experimental farm in São Domingos, PB. A randomized block design was adopted, in a 5 × 3 factorial scheme, with five levels of electrical conductivity of irrigation water—ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m⁻¹)—and three genotypes of sour passion fruit (Gigante Amarelo—‘BRS GA1’; Sol do Cerrado—‘BRS SC1’; and Catarina—‘SCS 437’. The increase in the electrical conductivity of irrigation water negatively affected most of the physiological characteristics of the sour passion fruit at 154 days after transplanting. Significant differences were observed between sour passion fruit genotypes when its tolerance was subjected to the salinity of irrigation water. There was an increase in the percentage of damage to the cell membrane with the increase in the electrical conductivity of irrigation water, with maximum values of 70.63, 60.86, and 80.35% for the genotypes ‘BRS GA1’, ‘BRS SC1’, and SCS 437’, respectively, when irrigated with water of 3.5 dS m⁻¹. The genotype ‘BRS Sol do Cerrado’ showed an increase in the synthesis of photosynthetic pigments when irrigated with water of 3.5 dS m⁻¹, with maximum values estimated at 1439.23 μg mL⁻¹ (Chl a); 290.96 μg mL⁻¹ (Chl b); 1730.19 μg mL−1 (Chl t); and 365.84 μg mL⁻¹ (carotenoids). An increase in photosynthetic efficiency parameters (F₀, Fm, and Fv) of the genotype ‘BRS Gigante Amarelo’ was observed when cultivated with water with high electrical conductivity (3.5 dS m⁻¹). Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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18 pages, 5084 KiB

Open AccessArticle

Foliar Application of Melatonin Positively Affects the Physio-Biochemical Characteristics of Cotton (Gossypium hirsutum L.) under the Combined Effects of Low Temperature and Salinity Stress

by Yuanyuan Fu, Lang Xin, Abdoul Kader Mounkaila Hamani, Weihao Sun, Hongbo Wang, Abubakar Sunusi Amin, Xingpeng Wang, Anzhen Qin and Yang Gao

Plants 2023, 12(21), 3730; https://doi.org/10.3390/plants12213730 - 31 Oct 2023

Cited by 8 | Viewed by 1780

Abstract

Low temperature and soil salinization during cotton sowing and seedling adversely affect cotton productivity. Exogenous melatonin (MT) can alleviate the damage caused to plants under non-biological stress; thus, applying MT is a means to improve the growth condition of crops under stress. However, [...] Read more.

Low temperature and soil salinization during cotton sowing and seedling adversely affect cotton productivity. Exogenous melatonin (MT) can alleviate the damage caused to plants under non-biological stress; thus, applying MT is a means to improve the growth condition of crops under stress. However, achieving this goal requires a thorough understanding of the physiological regulatory mechanisms of MT on cotton seedlings under low temperature and salinity stress. This study could bring new knowledge on physio-biochemical mechanisms that improve the tolerance of cotton seedlings to combined effects of low temperature and salt stress using an exogenous foliar application of MT. The phytotron experiment comprised two temperature levels of cold stress and control and five MT treatments of 0, 50, 100, 150, and 200 μM and two salinity levels of 0 and 150 mM NaCl. Compared with the control treatments (non-salinity stress under cold stress and control), the combined stress of salt and low temperature reduced cotton seedlings’ biomass and net photosynthetic rate (P_n), aggravated the membrane damage, reduced the potassium (K⁺) content, and increased the sodium (Na⁺) accumulation in the leaves and roots. Under NaCl stress, exogenously sprayed 50–150 μM MT increased the biomass and gas exchange parameters of cotton seedlings under salt and low temperature combined with salt stress, reduced the degree of membrane damage, and regulated the antioxidant enzyme, ion homeostasis, transport, and absorption of cotton seedlings. The pairwise correlation analysis of each parameter using MT shows that the parameters with higher correlation with MT at cold stress are mainly malondialdehyde (MDA), peroxidase (POD), and catalase (CAT). The highest correlation coefficient at 25 °C is observed between the K⁺ and Na⁺ content in cotton seedlings. The conclusion indicates that under salt and low-temperature stress conditions, exogenous application of MT primarily regulates the levels of P_n, superoxide dismutase (SOD), andPOD in cotton seedlings, reduces Na⁺ and MDA content, alleviates damage to cotton seedlings. Moreover, the most significant effect was observed when an exogenous application of 50–150 μM of MT was administered under these conditions. The current study’s findings could serve as a scientific foundation for salinity and low-temperature stress alleviation during the seedling stage of cotton growth. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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The Role of Plant Ubiquitin-like Modifiers in the Formation of Salt Stress Tolerance

by Siarhei A. Dabravolski and Stanislav V. Isayenkov

Plants 2024, 13(11), 1468; https://doi.org/10.3390/plants13111468 - 25 May 2024

Viewed by 1309

Abstract

The climate-driven challenges facing Earth necessitate a comprehensive understanding of the mechanisms facilitating plant resilience to environmental stressors. This review delves into the crucial role of ubiquitin-like modifiers, particularly focusing on ATG8-mediated autophagy, in bolstering plant tolerance to salt stress. Synthesising recent research, [...] Read more.

The climate-driven challenges facing Earth necessitate a comprehensive understanding of the mechanisms facilitating plant resilience to environmental stressors. This review delves into the crucial role of ubiquitin-like modifiers, particularly focusing on ATG8-mediated autophagy, in bolstering plant tolerance to salt stress. Synthesising recent research, we unveil the multifaceted contributions of ATG8 to plant adaptation mechanisms amidst salt stress conditions, including stomatal regulation, photosynthetic efficiency, osmotic adjustment, and antioxidant defence. Furthermore, we elucidate the interconnectedness of autophagy with key phytohormone signalling pathways, advocating for further exploration into their molecular mechanisms. Our findings underscore the significance of understanding molecular mechanisms underlying ubiquitin-based protein degradation systems and autophagy in salt stress tolerance, offering valuable insights for designing innovative strategies to improve crop productivity and ensure global food security amidst increasing soil salinisation. By harnessing the potential of autophagy and other molecular mechanisms, we can foster sustainable agricultural practices and develop stress-tolerant crops resilient to salt stress. Full article

(This article belongs to the Special Issue Mitigation Strategies and Tolerance of Plants to Abiotic Stresses)

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