Negative Roles of Strigolactone-Related SMXL6, 7 and 8 Proteins in Drought Resistance in Arabidopsis
Negative Roles of Strigolactone-Related SMXL6, 7 and 8 Proteins in Drought Resistance in Arabidopsis
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DOI：
10.3390/biom10040607
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发表时间：
2020-04-01
期刊：
影响因子：
5.5
通讯作者：
Lam-Son Phan Tran
中科院分区：
文献类型：
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作者：
Li, Weiqiang;Kien Huu Nguyen;Lam-Son Phan Tran
先前的研究表明，SUPPROORS OF MAX 2 1-LIKE 6、7和8（SMXL 6、7和8）蛋白冗余地抑制植物生长和发育中的独脚金内酯（SL）信号传导。近年来，通过对SL生物合成相关基因的功能分析和SL信号的正调控，越来越多的证据表明SL正调控植物的抗旱性。然而，SL信号负调节子SMXL 6、7和8在抗旱性中的功能及其相关机制仍不清楚。为了揭示这些SMXL蛋白的功能，我们分析了三重smx 16，7，8突变体植物的抗旱表型，并研究了几个抗旱相关性状。结果表明，smx 16、7、8突变体比野生型植株具有更强的抗旱性。生理研究表明，与野生型植株相比，smxl 6，7，8突变体植株表现出较高的叶表面温度，降低角质层渗透性，以及干旱诱导的水分流失和细胞膜损伤的减少。此外，smxl 6、7、8突变体植物在干旱期间表现出花色苷生物合成增加、解毒能力增强以及在子叶开放和生长抑制测定中对脱落酸的敏感性增加。一些相关基因的表达水平与所检测的生理生化性状之间存在良好的相关性。我们的研究结果共同表明，SMXL 6，7和8作为抗旱性的负调控因子，这些SMXL基因在作物中的破坏可能提供一种新的方式来提高其抗旱性。
Previous investigations have shown that the SUPPRESSORS OF MAX2 1-LIKE6, 7 and 8 (SMXL6, 7 and 8) proteins redundantly repress strigolactone (SL) signaling in plant growth and development. Recently, a growing body of evidence indicated that SLs positively regulate plant drought resistance through functional analyses of genes involved in SL biosynthesis and positive regulation of SL signaling. However, the functions of the SL-signaling negative regulators SMXL6, 7 and 8 in drought resistance and the associated mechanisms remain elusive. To reveal the functions of these SMXL proteins, we analyzed the drought-resistant phenotype of the triple smxl6,7,8 mutant plants and studied several drought resistance-related traits. Our results showed that the smxl6,7,8 mutant plants were more resistant to drought than wild-type plants. Physiological investigations indicated that the smxl6,7,8 mutant plants exhibited higher leaf surface temperature, reduced cuticle permeability, as well as decreases in drought-induced water loss and cell membrane damage in comparison with wild-type plants. Additionally, smxl6,7,8 mutant plants displayed an increase in anthocyanin biosynthesis during drought, enhanced detoxification capacity and increased sensitivity to abscisic acid in cotyledon opening and growth inhibition assays. A good correlation between the expression levels of some relevant genes and the examined physiological and biochemical traits was observed. Our findings together indicate that the SMXL6, 7 and 8 act as negative regulators of drought resistance, and that disruption of these SMXL genes in crops may provide a novel way to improve their drought resistance.