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

通过对拟南芥（Arabidopsis thaliana）三突变体smx16、7、8的耐旱表型分析，研究了独角麦内酯信号负调控因子SMXL6、7和8在抗旱中的作用及其机制，并研究了几种抗旱相关性状。综上所述，SMXL6、7和8对水稻抗旱性具有负调控作用。这项研究的发现表明，破坏这些作物中的SMXL基因可能提供一种新的方法来提高它们的抗旱性。与上述研究结果一致，拟南芥中独角麦内酯和karrikin受体DWARF14 （D14）和karrikin不敏感2 （KAI2）分别正调控耐旱性。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进行比较分析，旨在鉴定干旱条件下D14和KAI2特异性或共同调控的基因。结果表明，参与细胞分裂素和油菜素类固醇代谢的部分基因可能受到D14通路的特异性调控，而与光合作用、硫代葡萄糖苷和海藻糖代谢相关的部分基因可能同时受到D14和KAI2通路的调控。

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.