Key Laboratory of Agricultural Microbiology of Heilongjiang Province, Northeast Agricultural University, Harbin 150030, China.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
J Agric Food Chem. 2023 May 17;71(19):7348-7358. doi: 10.1021/acs.jafc.3c00559. Epub 2023 May 2.
Rice direct seeding technology has been considered as a promising alternative to traditional transplanting because of its advantages in saving labor and water. However, the poor emergence and seedling growth caused by chill stress are the main bottlenecks in wide-scale adoption of direct-seeded rice in Heilongjiang Province, China. Here, we found that natural plant growth regulator guvermectin (GV) effectively improved rice seed germination and seedling growth under chilling stress. Results from 2 year field trials showed that seed-soaking with GV not only enhanced the emergence rate and seedling growth but also increased the panicle number per plant and grain number per panicle, resulting in 9.0 and 6.8% increase in the yield of direct-seeded rice, respectively. Integrative physiological, transcriptomic, and metabolomic assays revealed that GV promoted seed germination under chilling stress mainly by enhancing the activities of α-amylase and antioxidant enzymes (superoxide dismutase, peroxidase, and catalase), increasing the contents of soluble sugar and soluble protein, improving the biosynthesis of glutathione and flavonoids, as well as activating gibberellin-responsive transcription factors and inhibiting the abscisic acid signaling pathway. These findings indicate that seed-soaking with GV has good potential to improve seedling establishment and yield of direct-seeded rice even under chilling stress.
水稻直播技术由于其省工节水的优势，被认为是传统移栽的一种很有前途的替代方法。然而，在黑龙江省，低温胁迫导致的出苗不良和幼苗生长缓慢是直播水稻广泛应用的主要瓶颈。在这里，我们发现天然植物生长调节剂藜芦碱（GV）能有效提高水稻在低温胁迫下的种子萌发和幼苗生长。两年田间试验结果表明，用 GV 浸种不仅能提高出苗率和幼苗生长，还能增加每株穗数和每穗粒数，从而使直播水稻的产量分别提高 9.0%和 6.8%。综合生理、转录组和代谢组学分析表明，GV 主要通过增强α-淀粉酶和抗氧化酶（超氧化物歧化酶、过氧化物酶和过氧化氢酶）的活性，增加可溶性糖和可溶性蛋白的含量，改善谷胱甘肽和类黄酮的生物合成，以及激活赤霉素响应转录因子和抑制脱落酸信号通路来促进种子在低温胁迫下的萌发。这些发现表明，用 GV 浸种具有很好的潜力，可以改善直播水稻的幼苗建立和产量，即使在低温胁迫下也是如此。
