Cholesterol accumulation by suppression of SMT1 leads to dwarfism and improved drought tolerance in herbaceous plants
Cholesterol accumulation by suppression of SMT1 leads to dwarfism and improved drought tolerance in herbaceous plants
复制标题
通过抑制 SMT1 来积累胆固醇会导致草本植物矮化并提高耐旱性
DOI：
10.1111/pce.13168
复制
发表时间：
2018-06-01
影响因子：
7.3
通讯作者：
Lu, Shaoyun
中科院分区：
文献类型：
--
作者：
Chen, Miao;Chen, Jingjing;Lu, Shaoyun
矮秆和耐旱性是许多作物育种中有价值的两个性状。在这项研究中，我们报道了胆固醇在调节植物生长和耐旱性方面的新的生理作用。与野生型相比，具有矮化和抗旱性的狗牙根突变体的SMT1基因转录水平显著降低，伴随着胆固醇的积累，包括SAMDC在内的一小部分基因的转录水平上升，腐胺(Put)、亚精胺(Spd)和精胺(Spm)的浓度增加。通过RNA干扰下调OsSMT1的表达，在转基因水稻中引起了类似的表型变化。此外，外源胆固醇还导致狗牙根和水稻中一组相似基因的转录增加，Put、Spd和Spm水平升高，耐旱性提高，株高降低。我们发现，是Spm而不是Spd导致狗牙根和水稻的高度降低。综上所述，我们认为胆固醇诱导SAMDC的表达，并通过促进Spd和Spm的合成而导致植物的矮化和耐旱性提高。
Dwarfism and drought tolerance are 2 valuable traits in breeding of many crops. In this study, we report the novel physiological roles of cholesterol in regulation of plant growth and drought tolerance. Compared with the wild type, sterol-C24-methyltransferase 1 (SMT1) gene transcript was greatly reduced in a bermudagrass mutant with dwarfism and enhanced drought tolerance, accompanied with cholesterol accumulation, elevated transcript levels of a small group of genes including SAMDC, and increased concentrations of putrescine (Put), spermidine (Spd), and spermine (Spm). Knock-down of OsSMT1 expression by RNA interference resulted in similar phenotypic changes in transgenic rice. Moreover, exogenously applied cholesterol also led to elevated transcripts of a similar set of genes, higher levels of Put, Spd, and Spm, improved drought tolerance, and reduced plant height in both bermudagrass and rice. We revealed that it is Spm, but not Spd, that is responsible for the height reduction in bermudagrass and rice. In conclusion, we suggest that cholesterol induces expression of SAMDC and leads to dwarfism and elevated drought tolerance in plants as a result of the promoted Spd and Spm synthesis.