Mechanisms of SMXL6, 7 and 8 proteins in Arabidopsis plant adaptation to drought

本研究通过分析拟南芥三倍体smx16、7、8突变体的耐旱性表型，研究了植物内酯信号负调控因子SMXL6、7和8在耐旱性中的作用及其相关机制，并对几个与干旱相关的性状进行了研究。我们的结果表明，SMXL6、7和8在抗旱性方面起负调控作用。本研究的结果表明，在作物中阻断这些SMXL基因可能会为提高作物的抗旱性提供一种新的途径。与上述研究结果一致的是，Strigolacone和Karrikin受体DWARF14(D14)和Karrikin不敏感2(KAI2)分别被证明对拟南芥的抗旱性具有正向调节作用。然后，我们旨在通过对拟南芥d14-1和KAI2-2突变体在脱水条件下的转录组数据的比较分析，找出干旱条件下受D14和KAI2特异或共同调控的基因。结果表明，一些参与细胞分裂素和油菜素类固醇代谢的基因可能受D14途径的特异性调控，而一些与硫代葡萄糖苷和海藻糖的光合作用和代谢相关的基因可能受D14和KAI2途径的共同调控。

We studied the functions of the strigolactone-signaling negative regulators SMXL6,7 and 8 in drought tolerance and the associated mechanisms by analyzing the drought-tolerant phenotype of the Arabidopsis thaliana triple smxl6,7,8 mutant plants and studied several drought tolerance-related traits. Our results together indicate that the SMXL6, 7 and 8 act as negative regulators of drought tolerance. The findings of this study suggest that disruption of these SMXL genes in crops may provide a novel way to improve their drought tolerance.Consistent with the results of the above study, strigolactone and karrikin receptors, DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2), respectively, have been shown to positively regulate drought tolerance in Arabidopsis. We then aimed to identify genes specifically or commonly regulated by D14 and KAI2 under drought, using comparative analysis of the transcriptome data of the A. thaliana d14-1 and kai2-2 mutants under dehydration conditions. Results suggest that some genes involved in cytokinin and brassinosteroid metabolism might be specifically regulated by the D14 pathway, whereas some genes related to photosynthesis and metabolism of glucosinolates and trehalose are potentially regulated by both D14 and KAI2 pathways in plant response to dehydration.