Leaf senescence is a developmental process designed for nutrient recycling and relocation to maximize growth competence and reproductive capacity of plants. Thus, plants integrate developmental and environmental signals to precisely control senescence. To genetically dissect the complex regulatory mechanism underlying leaf senescence, we identified an early leaf senescence mutant, rse1. RSE1 encodes a putative glycosyltransferase. Loss-of-function mutations in RSE1 resulted in precocious leaf yellowing and up-regulation of senescence marker genes, indicating enhanced leaf senescence. Transcriptome analysis revealed that salicylic acid (SA) and defense signaling cascades were up-regulated in rse1 prior to the onset of leaf senescence. We found that SA accumulation was significantly increased in rse1. The rse1 phenotypes are dependent on SA-INDUCTION DEFICIENT 2 (SID2), supporting a role of SA in accelerated leaf senescence in rse1. Furthermore, RSE1 protein was localized to the cell wall, implying a possible link between the cell wall and RSE1 function. Together, we show that RSE1 negatively modulates leaf senescence through an SID2-dependent SA signaling pathway.
Bibliographical noteFunding Information:
We thank Kee Hoon Sohn (POSTECH) for providing sid2-1 and pad4-1 seeds and Sunghyun Hong (IBS) for helpful discussion. Funding. This work was supported by the Institute for Basic Science (IBSR013-G2 and in part by IBS-R013-D1) and a grant from National Research Foundation (2019R1A2C3007376), and in part by start-up funds from DGIST to JK.
© Copyright © 2020 Lee, Kim, Lee, Jeon, Kwak and Kim.
All Science Journal Classification (ASJC) codes
- Plant Science