Potential Roles of Three ABCB Genes in Quinclorac Resistance Identified in Echinochloa crus-galli var. zelayensis
, Yongli Guo 1,2, Xudong Liu 1,2, Yuan Gao 1,2, Yu Sun 1,2, Liyao Dong 1,2 and Jun Li 1,2,*
Round 1
Reviewer 1 Report
In this manuscript, the authors elucidated the potential role of three ABCB genes in quiclorac resistance identified in Echinochloa crus-galli. The authors used the previously isolated susceptible biotype JNNX-S and resistant biotype SSXB-R. Resistant lines had significantly longer root lengths than susceptible lines after quinclorac or NPA treatment. IAA content after quinclorac or NPA treatment was higher in susceptible plants. Then, the authors isolated three partial ABCB genes (EcABC1, EcABCB4, and EcABCB19), since ABCBs are involved in IAA influx and efflux in Arabidopsis thaliana. No mutation was found on partial genes between susceptible and resistant biotypes. However, qRT-PCR showed that different gene expression patterns between susceptible and resistant biotypes. Finally, they elucidated the susceptibility of Arabidopsis ABCB mutants toward quinclorac.
I have several concerns that the authors should address in order to improve this manuscript.　
Major points
The authors isolated the partial ABCB genes from E crus-galli. I strongly encouraged to isolate full length cDNAs to rule out the possibility there are mutations outside of the partially amplified sequence. Also, please give detail how did you find ABCB genes from E crus-galli genome. In addition, please provide detailed information about the ABCB gene, such as how many ABCB genes are in the E. crus-galli genome and the homology to Arabidopsis thaliana ABCB genes. Adding a phylogenetic tree might make it easier to see the relationship between E. crus-gall other plant ABCB genes.
The authors showed that differential gene expression patterns of EcABCB gene between susceptible and resistance biotypes. However, the function of these ABCB has not been elucidated. Therefore, it is uncertain whether EcABCBs have the same function as AtABCBs. Thus, it is difficult to get insights from the qRT-PCR results. Therefore, I think the authors generate transgenic Arabidopsis expressing EcABCB genes and compare the quinclorac susceptibility between transgenic and WT Arabidospsis.
This manuscript investigates the ABCBs involved in quinclorac resistance in E. crus-galli. Therefore, it is not very important to investigate the quinclorac susceptibility of AtABCB mutants of Arabidopsis thaliana. Therefore, to complete the story, EcABCB-expressing transgenic Arabidospsis should be created as described above and their quinclorac susceptibility should be examined.
Quantification of IAA using ELISA is not familiar to me. To show the method is appropriate, give detail of ELISA used in this study such as specificity to IAA.
Minor points
L41
Spell out IAA
L50
Italicize “Arabidopsis thaliana”
L79-84
Give detailed information of previously isolated susceptible and resistant biotypes so the readers do not have to read the reference paper.
L88
Add final concentration of DMSO.
L98
Indole-3-acetic acid (IAA) -> IAA
L110
Spell out TWQ
L161
Please specify the p-value when you considered it to be significant.
Table S3
Add the PCR efficiency of each primer set.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear authors, find my comments in the attached file.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The article by Yuanlin et al. reported the potential roles of three ABCB genes in quinclorac resistance in Echinochloa crus-galli var. zelayensis. They explored a new mechanism of resistance to quinclorac. Overall, the topic was interesting, the experiments were properly designed, the analyses were sound, and the manuscript was well organized and presented. There are only a few minor technical errors in the manuscript: lines: 190, 193, 198 and 242.
Sincerely, I suggest that the editor, after minor revision, accepts manuscript under the title:
,, Potential roles of three ABCB genes in quinclorac resistance identified in Echinochloa crus-galli var. zelayensis’’ and approve its publication in the journal Agronomy.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
