Abstract
Soil salinity is one of the major threats to agricultural productivity worldwide. Salt stress exposure alters root and shoot growth rates, thereby affecting overall plant performance. While past studies have extensively documented the effect of salt stress on root elongation and shoot development separately, here we take an innovative approach by examining the coordination of root and shoot growth under salt stress conditions. Utilizing a newly developed tool for quantifying the root:shoot ratio in agar-grown Arabidopsis seedlings, we found that salt stress results in a loss of coordination between root and shoot growth rates. We identify a specific gene cluster encoding domain-of-unknown-function 247 (DUF247), and characterize one of these genes as Salt Root:shoot Ratio Regulator Gene (SR3G). Further analysis elucidates the role of SR3G as a negative regulator of salt stress tolerance, revealing its function in regulating shoot growth, root suberization, and sodium accumulation. We further characterize that SR3G expression is modulated by WRKY75 transcription factor, known as a positive regulator of salt stress tolerance. Finally, we show that the salt stress sensitivity of wrky75 mutant is completely diminished when it is combined with sr3g mutation. Together, our results demonstrate that utilizing root:shoot ratio as an architectural feature leads to the discovery of new stress resilience gene. The study’s innovative approach and findings not only contribute to our understanding of plant stress tolerance mechanisms but also open new avenues for genetic and agronomic strategies to enhance crop environmental resilience.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
mri23{at}cornell.edu, hs995{at}cornell.edu, huyf19{at}lzu.edu.cn, mdalqahtani{at}pnu.edu.sa, ejc35{at}cornell.edu, ronell.sicat{at}kaust.edu.sa, minwang{at}ucdavis.edu, ly76{at}cornell.edu, rachid.aithaddou{at}kfupm.edu.sa, li_bo{at}lzu.edu.cn, gdrakakaki{at}ucdavis.edu, an425{at}cornell.edu, map25{at}cornell.edu, arthur.korte{at}uni-wuerzburg.de, lukasz.jaremko{at}kaust.edu.sa, christa.testerink{at}wur.nl, mark.tester{at}kaust.edu.sa
We have addressed the comments raised by the reviewers during the eLife peer revision, including rephrasing some of the significance of our findings, adding statistical analysis, and ensuring that supplemental figures are correctly labeled.