Spermidine regulates wheat grain weight at high planting density by promoting the synthesis of sucrose and starch in inferior grains

Published Date
May 14, 2024
Type
Journal Article
Spermidine regulates wheat grain weight at high planting  density by promoting the synthesis of sucrose and  starch in inferior grains
Authors:
Juan Li
Zimeng Liang, Jingyi Feng, HuiHui Li, Vinay Nangia, Fei Mo, Yang Liu

Increasing density is an effective way to enhance wheat (Triticum aestivum L.) yield under limited cultivated areas. However, the physiological mechanisms underlying the reduction in grain weight when density increased are still unclear. Three field experiments were conducted during the 2014–2019 growing seasons to explore the physiological mechanisms by which polyamines affect grain weight formation. The results showed that when wheat planting density exceeded 450 104 seedlings ha 1 and 525 104 seedlings ha 1, wheat yield tended to decrease. Compared to moderate density (DM, 450 104 seedlings ha 1), the filling rate of inferior grains was reduced before 25 days after anthesis (DAA) and the active filling period was shortened by 6.4%–7.4% under high density (DH, 600 104 seedlings ha 1), resulting in a loss of 1000-grain weight by 5.4%–8.1%. DH significantly reduced sucrose and starch content in inferior grains at the filling stage. Meanwhile, DH inhibited the activity of key enzymes involved in polyamine synthesis [SAMDC (EC 4.1.1.50) and SpdSy (EC 2.5.1.16)] and induced the activity of ethylene (ETH) precursor synthase, resulting in a significant decrease in endogenous spermidine (Spd) content in inferior grains, but a significant increase in ETH release rate. Post-flowering application of exogenous Spd increased the accumulation of sucrose and starch in the inferior grains and positively regulated the filling and grain weight of the inferior grains, whereas exogenous ETH had a negative effect. Overall, Spd may affect wheat grain weight at high planting density by promoting the synthesis of sucrose and starch in inferior grains.

Citation:
Juan Li, Zimeng Liang, Jingyi Feng, HuiHui Li, Vinay Nangia, Fei Mo, Yang Liu. (14/5/2024). Spermidine regulates wheat grain weight at high planting density by promoting the synthesis of sucrose and starch in inferior grains. Physiologia Plantarum, 176 (3).
Keywords:
triticum aestivum l.
wheat grain
yield