Mei Wanqi, Yang Shaoxia, Xiong Jian, Khan Aaqil, Zhao Liming, Du Xiaole, Huo Jingxin, Zhou Hang, Sun Zhiyuan, Yang Xiaohui, Yue Nana, Feng Naijie, Zheng Dianfeng
College of Coastal Agriculture Sciences, Guangdong Ocean University, Zhanjiang 524088, China.
South China Center of National Saline-Tolerant Rice Technology Innovation Center, Zhanjiang 524088, China.
Plants (Basel). 2025 Jan 11;14(2):188. doi: 10.3390/plants14020188.
Salt stress is a vital environmental stress that severely limits plant growth and productivity. Prohexadione-calcium (Pro-Ca) has been extensively studied to regulate plant growth, development, and stress responses. However, the constructive role of Pro-Ca in alleviating damages and enhancing rice tillers' morph-physiological characteristics under salt stress remains largely unknown. The results showed that Pro-Ca significantly improved Changmaogu's (CMG's) productive tillering rate and the total yield per plant by 17.1% and 59.4%, respectively. At tillering stage, the results showed that Pro-Ca significantly improved the morph-physiological traits, i.e., leaf area, and photosynthetic traits of the rice variety with salt tolerance, under NaCl stress. Pro-Ca significantly increased the seedling index of the main stem and tiller by 10.3% and 20.0%, respectively. Pro-Ca significantly increased the chlorophyll (chl ), chlorophyll (chl ) and carotenoid contents by 32.8%, 58.4%, and 33.2%, respectively under NaCl stress. Moreover, Pro-Ca significantly enhanced the net photosynthetic rate () by 25.0% and the non-photochemical (NPQ) by 9.0% under NaCl stress. Furthermore, the application of Pro-Ca increased the activities of antioxidant enzymes by 7.5% and 14.7% in superoxide dismutase (SOD), 6.76% and 18.0% in peroxidase (POD), 26.4% and 58.5% in catalase (CAT), 11.0% and 15.9% in ascorbate peroxidase (APX), and Pro-Ca reduced the membrane damage index by 10.8% and 2.19% in malondialdehyde (MDA) content, respectively, for main stem and tiller leaves under NaCl stress. Pro-Ca significantly enhanced the soluble protein content of the main stem and tiller leaves by 2.60% and 6.08%, respectively. The current findings strongly suggested that exogenous application of Pro-Ca effectively alleviated the adverse impact of NaCl stress on the main stem and tillers by enhancing the photosynthetic capacity and antioxidant enzyme activity, and ultimately increased the productive tillering rate and grain yield.
盐胁迫是一种重要的环境胁迫，严重限制植物生长和生产力。已对调环酸钙（Pro-Ca）进行了广泛研究，以调控植物生长、发育及胁迫响应。然而，Pro-Ca在缓解盐胁迫对水稻分蘖造成的损害及增强其形态生理特性方面的建设性作用在很大程度上仍不为人知。结果表明，Pro-Ca显著提高了长茂谷（CMG）的有效分蘖率和单株总产量，分别提高了17.1%和59.4%。在分蘖期，结果显示，在NaCl胁迫下，Pro-Ca显著改善了耐盐水稻品种的形态生理性状，即叶面积和光合性状。Pro-Ca使主茎和分蘖的幼苗指数分别显著提高了10.3%和20.0%。在NaCl胁迫下，Pro-Ca使叶绿素（chl）、叶绿素（chl）和类胡萝卜素含量分别显著提高了32.8%、58.4%和33.2%。此外，在NaCl胁迫下，Pro-Ca使净光合速率（）显著提高了25.0%，非光化学猝灭（NPQ）提高了9.0%。此外，施用Pro-Ca使超氧化物歧化酶（SOD）的抗氧化酶活性提高了7.5%和14.7%，过氧化物酶（POD）提高了6.76%和18.0%，过氧化氢酶（CAT）提高了26.4%和58.5%，抗坏血酸过氧化物酶（APX）提高了11.0%和15.9%，并且Pro-Ca使NaCl胁迫下主茎和分蘖叶片的丙二醛（MDA）含量的膜损伤指数分别降低了10.8%和2.19%。Pro-Ca使主茎和分蘖叶片的可溶性蛋白含量分别显著提高了2.60%和6.08%。当前研究结果有力地表明，外源施用Pro-Ca通过增强光合能力和抗氧化酶活性，有效缓解了NaCl胁迫对主茎和分蘖的不利影响，最终提高了有效分蘖率和籽粒产量。
