Post‐anthesis saline‐alkali stress inhibits grain filling by promoting ethylene production and signal transduction

Saline-alkali stress is one of the major abiotic stresses that severely affect rice yield. However, mechanism by which saline-alkali regulates grain filling in still unclear. In this study, Oryza sativa L. spp. Indica cultivar Chaoyou1000 (C1000) was exposed to post-anthesis conditions at 6 days after anthesis, significantly reduced weight suppressing accumulation starch and non-structural carbohydrates grains. Further analysis found 1-aminocyclopropane-1-carboxylate (ACC), a precursor for ethylene, increased treatment. qRT-PCR results showed several key genes involved ethylene biosynthesis, including OsACS OsACO genes, were upregulated saline-alkali-treated addition, signalling pathway also induced stress. Exogenous application both NSC contents grains C1000, suggesting saline-alkali-induced has negative effect on filling. Furthermore, gene expression levels OsSUS, OsAGPL, OsAGPS, OsSSI OsSSIIIa, are biosynthesis pathway, downregulated agreement, assays these enzymes further revealed decreased activities sucrose synthase (SUS), adenosine diphosphate glucose pyrophosphorylase (AGP) (StS). Together, our indicated suppressed enzyme conversion elevating production, led inhibition