Proteomic analysis of salicylic acid regulation of grain filling of two near-isogenic rice (Oryza sativa L.) varieties under soil drying condition

• Published in: Plant physiology and biochemistry 2020-06, Vol.151, p.659-672
• Main Authors: Kimbembe, Romesh Eric Romy, Li, Guangyan, Fu, Guanfu, Feng, Baohua, Fu, Weimeng, Tao, Longxing, Chen, Tingting
• Format: Article
• Language: English
• Subjects: Grain filling; Protein expression; Rice (Oryza sativa L.); Salicylic acid; Soil drying
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.04.006

Grain filling is the final determinant of yield, and this process is susceptible to abiotic stresses. Salicylic acid (SA) regulates grain filling in rice plants. A comparative proteomic study was conducted to understand how SA mediates grain filling under soil drying (SD) condition. Zhefu802 and its near-isogenic line (NIL) were planted in pots in an artificial chamber. SA (100 mg L−1) was applied, followed by SD treatment (with a water potential of −30 to −35 kPa) at anthesis. The results showed that the grain yield and grain weight significantly decreased under SD in Zhefu802, but not in its NIL variety. SD also decreased expression of photosynthesis-related proteins in grains of Zhefu802, which resulted in its poorer drought resistance. Furthermore, the decreased grain filling rate rather than the grain size explained the observed decreased grain weight and grain yield under SD. Interestingly, these reductions were reversed by SA. Expression of proteins involved in glycolysis/TCA circle, starch and sucrose metabolism, antioxidation and detoxication, oxidative phosphorylation, transcription, translation, and signal transduction, were significantly down-regulated under SD and were significantly up-regulated in response to SA. The expression of these proteins was examined at transcriptional level and similar results were obtained. Inhibited expression of these proteins and related pathways contributed to the observed decrease in the grain filling rate of Zhefu802, and application of SA up-regulated expression of these proteins to improve grain weight. The findings of this study provide new insights into grain filling regulation by SA, and offer the scientific foundation for cultivation practice. •Soil drying decreased the grain weight and grain filling rate of Zhefu802.•Decreased expression of proteins that function in photosynthesis in grains are account for its poor drought resistance.•SA increased the grain weight and grain filling rate of Zhefu802 under soil drying.•Proteins that relate to glycolysis, TCA circle, oxidative phosphorylation mainly function in the grain filling regulation.•Up-regulation of these proteins caused by SA attributes to the improved grain weight and grain filling under soil drying.