The BioActives Lab, Center for Desert Agriculture (CDA), Biological and Environment Science and Engineering (BESE), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
Commun Biol. 2021 Oct 25;4(1):1222. doi: 10.1038/s42003-021-02740-8.
The apocarotenoid zaxinone promotes growth and suppresses strigolactone biosynthesis in rice. To shed light on the mechanisms underlying its growth-promoting effect, we employed a combined omics approach integrating transcriptomics and metabolomics analysis of rice seedlings treated with zaxinone, and determined the resulting changes at the cellular and hormonal levels. Metabolites as well as transcripts analysis demonstrate that zaxinone application increased sugar content and triggered glycolysis, the tricarboxylic acid cycle and other sugar-related metabolic processes in rice roots. In addition, zaxinone treatment led to an increased root starch content and induced glycosylation of cytokinins. The transcriptomic, metabolic and hormonal changes were accompanied by striking alterations of roots at cellular level, which showed an increase in apex length, diameter, and the number of cells and cortex cell layers. Remarkably, zaxinone did not affect the metabolism of roots in a strigolactone deficient mutant, suggesting an essential role of strigolactone in the zaxinone growth-promoting activity. Taken together, our results unravel zaxinone as a global regulator of the transcriptome and metabolome, as well as of hormonal and cellular composition of rice roots. Moreover, they suggest that zaxinone promotes rice growth most likely by increasing sugar uptake and metabolism, and reinforce the potential of this compound in increasing rice performance.
类胡萝卜素降解产物玉米黄质酮促进水稻生长并抑制独脚金内酯的生物合成。为了阐明其促进生长的作用机制，我们采用了一种整合转录组学和代谢组学分析的综合组学方法，对玉米黄质酮处理的水稻幼苗进行分析，并确定了细胞和激素水平的变化。代谢物和转录物分析表明，玉米黄质酮的应用增加了糖含量，并触发了水稻根系中的糖酵解、三羧酸循环和其他与糖相关的代谢过程。此外，玉米黄质酮处理导致根淀粉含量增加，并诱导细胞分裂素的糖基化。转录组、代谢和激素变化伴随着细胞水平上根系的显著改变，表现为根尖长度、直径以及细胞和皮层细胞层数的增加。值得注意的是，玉米黄质酮处理不会影响独脚金内酯缺失突变体中根的代谢，这表明独脚金内酯在玉米黄质酮促进生长的活性中起着重要作用。总之，我们的研究结果表明，玉米黄质酮是水稻根系转录组和代谢组以及激素和细胞组成的全局调节剂。此外，它们表明玉米黄质酮通过增加糖的吸收和代谢来促进水稻的生长，并增强了该化合物在提高水稻性能方面的潜力。
