Yang Xiaohui, Xiong Jian, Du Xiaole, Sun Minmin, Ding Linchong, Mei Wanqi, Sun Zhiyuan, Feng Naijie, Zheng Dianfeng, Shen Xuefeng
College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524008, China.
National Saline-Tolerant Rice Technology Innovation Center, South China, Zhanjiang 524008, China.
Plants (Basel). 2024 Dec 23;13(24):3599. doi: 10.3390/plants13243599.
Salt stress is one of the principal abiotic stresses limiting agricultural production and seriously inhibiting seed germination rates. This study selected the salt-tolerant rice variety HD961 and the salt-sensitive rice variety 9311 as experimental materials to investigate the physiological and metabolic effects of exogenous Spd seed priming on rice seeds and seedlings under NaCl stress. The experiment involved treating rice seeds with 0.1 mmol·L Spd and then subjecting them to 100 mmol·L NaCl stress for 24 h, with sampling for analysis at the 24 h and the four-leaf-one-heart stage. The results indicated that under NaCl stress, the rice's germination and vigor indices significantly decreased. However, exogenous Spd seed priming reduced the accumulation of malondialdehyde, enhanced the capacity for osmotic adjustment, and increased the amylase and antioxidant activity by 50.07% and 26.26%, respectively. Under NaCl stress, the morphological development of rice seedlings was markedly inhibited, whereas exogenous Spd seed priming improved the aboveground and belowground biomass of the rice under stress conditions, as well as the content of photosynthetic pigments. It also reduced the damage to seedlings from electrical conductivity, helped maintain ionic balance, and promoted the excretion of Na and Cl and the absorption of K and Ca. In the salt-sensitive rice variety 9311, the soluble protein content increased by 15.12% compared to the salt-tolerant rice variety HD961, especially under 100 mmol·L NaCl stress, when the effect of exogenous Spd seed priming was more pronounced. In summary, these findings might provide new research perspectives and strategies for improving the salt tolerance of rice under NaCl stress.
盐胁迫是限制农业生产的主要非生物胁迫之一，严重抑制种子发芽率。本研究选取耐盐水稻品种HD961和盐敏感水稻品种9311作为实验材料，研究外源亚精胺（Spd）引发种子对NaCl胁迫下水稻种子及幼苗的生理和代谢影响。实验用0.1 mmol·L Spd处理水稻种子，然后使其遭受100 mmol·L NaCl胁迫24 h，在24 h和四叶一心期取样分析。结果表明，在NaCl胁迫下，水稻的发芽和活力指数显著下降。然而，外源Spd引发种子降低了丙二醛的积累，增强了渗透调节能力，淀粉酶和抗氧化活性分别提高了50.07%和26.26%。在NaCl胁迫下，水稻幼苗的形态发育受到显著抑制，而外源Spd引发种子提高了胁迫条件下水稻地上部和地下部生物量以及光合色素含量。它还减少了电导率对幼苗的损伤，有助于维持离子平衡，促进Na和Cl的排出以及K和Ca的吸收。在盐敏感水稻品种9311中，可溶性蛋白含量比耐盐水稻品种HD961增加了15.12%，尤其是在100 mmol·L NaCl胁迫下，外源Spd引发种子的效果更明显。总之，这些发现可能为提高NaCl胁迫下水稻的耐盐性提供新的研究视角和策略。
