Integrated transcriptomic and metabolomic analysis provides insight into the regulation of leaf senescence in rice

Jiao Xue,Xiaofei Wang,Zhiqiang Fang,Wei Liu,Zhanhua Lu,Shiguang Wang,Dongbai Lu,Xiuying He

doi:10.1038/s41598-021-93532-x

Jiao Xue, Xiaofei Wang + Show 6 more

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https://doi.org/10.1038/s41598-021-93532-x

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Abstract

Leaf senescence is one of the most precisely modulated developmental process and affects various agronomic traits of rice. Anti-senescence rice varieties are important for breeding application. However, little is known about the mechanisms underlying the metabolic regulatory process of leaf senescence in rice. In this study, we performed transcriptomic and metabolomic analyses of the flag leaves in Yuenong Simiao (YN) and YB, two indica rice cultivars that differ in terms of their leaf senescence. We found 8524 genes/204 metabolites were differentially expressed/accumulated in YN at 30 days after flowering (DAF) compared to 0 DAF, and 8799 genes/205 metabolites were differentially expressed in YB at 30 DAF compared to 0 DAF. Integrative analyses showed that a set of genes and metabolites involved in flavonoid pathway were significantly enriched. We identified that relative accumulation of PHENYLALANINE AMMONIA-LYASE (PAL), CINNAMATE 4-HYDROXYLASE (C4H), 4-COUMAROYL-COA LIGASE (4CL), CHALCONE SYNTHASE (CHS) and CHALCONE ISOMERASE (CHI) in YN30/0 was higher than that in YB30/0. Three flavonoid derivatives, including phloretin, luteolin and eriodictyol, showed lower abundances in YB than in YN at 30 DAF. We further revealed a MYB transcription factor, which is encoded by OsR498G0101613100 gene, could suppress the expression of CHI and CHS. Our results suggested a comprehensive analysis of leaf senescence in a view of transcriptome and metabolome and would contribute to exploring the molecular mechanism of leaf senescence in rice.

Highlights

Leaf senescence is one of the most precisely modulated developmental process and affects various agronomic traits of rice
The leaf senescence database currently contains more than 180 senescence-associated genes (SAGs) experimentally identified in r ice[8]; these SAGs are involved in chloroplast degradation, hormones and transcription factors associated with photosynthesis, the energy metabolism pathway, nitrogen mobilization and so on
Given that the leaf colour change from green to yellow is a notable indicator of senescence of plants, we performed detailed physiological, biochemical and molecular assays to determine whether Yuenong Simiao (YN) has anti-senescence traits

Summary

Introduction

Leaf senescence is one of the most precisely modulated developmental process and affects various agronomic traits of rice. Little is known about the mechanisms underlying the metabolic regulatory process of leaf senescence in rice. In the process of breeding, whether the process of functional leaves turning from green to yellow is stable and smooth in the late-mature stage of rice is a concern of breeders. This stage is accompanied by the degradation of chlorophyll, pigment deposition and rapid changes in metabolite content. The leaf senescence database currently contains more than 180 SAGs experimentally identified in r ice[8]; these SAGs are involved in chloroplast degradation, hormones and transcription factors associated with photosynthesis, the energy metabolism pathway, nitrogen mobilization and so on. The biochemical basis and molecular regulatory mechanisms underlying these processes in rice are not clear

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