Abstract：
Food is a fundamental human right, and global food security is threatened by crop production. Plant growth regulators (PGRs) play an essential role in improving crop yield and quality, and this study reports on a novel PGR, termed guvermectin (GV), isolated from plant growth-promoting rhizobacteria, which can promote root and coleoptile growth, tillering, and early maturing in rice. GV is a nucleoside analogue like cytokinin (CK), but it was found that GV significantly promoted root and hypocotyl growth, which is different from the function of CK in Arabidopsis. The Arabidopsis CK receptor triple mutant ahk2-2 ahk3-3 cre1-12 still showed a GV response. Moreover, GV led different growth-promoting traits from auxin, gibberellin (GA), and brassinosteroid (BR) in Arabidopsis and rice. The results from a four-year field trial involving 28 rice varieties showed that seed-soaking treatment with GV increased the yields by 6.2 to 19.6%, outperforming the 4.0 to 10.8% for CK, 1.6 to 16.9% for BR, and 2.2 to 7.1% for GA-auxin-BR mixture. Transcriptome analysis demonstrated that GV induced different transcriptome patterns from CK, auxin, BR, and GA, and SAUR genes may regulate GV-mediated plant growth and development. This study suggests that GV represents a novel PGR with a unique signal perception and transduction pathway in plants.
摘要：
食物是一项基本人权，全球粮食安全受到作物生产的威胁。植物生长调节剂（PGRs）在提高作物产量和质量方面发挥着重要作用。这项研究报道了一种新颖的PGR，称为Guvermectin（GV），从植物生长促进根瘤菌中分离，可以促进根系和胚芽鞘生长，耕种,水稻早熟。GV是一种核苷类似物，如细胞分裂素（CK），但是发现GV显着促进了根和下胚轴的生长，这与拟南芥中CK的功能不同。拟南芥CK受体三重突变体ahk2-2ahk3-3cre1-12仍显示GV反应。此外，GV从生长素中导致不同的生长促进性状，赤霉素（GA），拟南芥和水稻中的油菜素类固醇（BR）。对28个水稻品种进行为期四年的田间试验结果表明，用GV浸种处理可使产量提高6.2％至19.6％，优于CK的4.0至10.8%，BR为1.6％至16.9％，GA-生长素-BR混合物为2.2至7.1%。转录组分析表明，GV诱导了与CK不同的转录组模式，生长素,BR,GA,SAUR基因可能调控GV介导的植物生长发育。这项研究表明，GV代表了一种新型的PGR，在植物中具有独特的信号感知和转导途径。
