Different strategies of strigolactone and karrikin signals in regulating the resistance of Arabidopsis thaliana to water-deficit stress

Strigolactone and karrikin receptors, DWARF14 (D14) and KARRIKIN INSENSITIVE 2 (KAI2), respectively, have been shown to positively regulate drought resistance inArabidopsis thalianaby modulating abscisic acid responsiveness, anthocyanin accumulation, stomatal closure, cell membrane integrity and cuticle formation. Here, we aim to identify genes specifically or commonly regulated by D14 and KAI2 under water scarcity, using comparative analysis of the transcriptome data of theA. thaliana d14-1andkai2-2mutants under dehydration conditions. In comparison with wild-type, under dehydration conditions, the expression levels of genes related to photosynthesis and the metabolism of glucosinolates and trehalose were significantly changed in bothd14-1andkai2-2mutant plants, whereas the transcript levels of genes related to the metabolism of cytokinins and brassinosteroids were significantly altered in thed14-1mutant plants only. These results suggest that cytokinin and brassinosteroid metabolism might be specifically regulated by the D14 pathway, whereas photosynthesis and metabolism of glucosinolates and trehalose are potentially regulated by both D14 and KAI2 pathways in plant response to water scarcity.

独脚金内酯和卡瑞肯受体，分别为DWARF14（D14）和KARRIKIN INSENSITIVE 2（KAI2），已被证明可通过调节脱落酸响应、花青素积累、气孔关闭、细胞膜完整性和角质层形成，正向调控拟南芥的抗旱性。在此，我们旨在通过对脱水条件下拟南芥d14 - 1和kai2 - 2突变体转录组数据的比较分析，鉴定在缺水条件下受D14和KAI2特异性或共同调控的基因。与野生型相比，在脱水条件下，d14 - 1和kai2 - 2突变体植株中与光合作用以及硫代葡萄糖苷和海藻糖代谢相关的基因表达水平均发生显著变化，而仅在d14 - 1突变体植株中与细胞分裂素和油菜素内酯代谢相关的基因转录水平发生显著改变。这些结果表明，细胞分裂素和油菜素内酯代谢可能受D14途径特异性调控，而光合作用以及硫代葡萄糖苷和海藻糖代谢在植物应对缺水时可能受D14和KAI2途径共同调控。