Polyamines (PAs), especially spermidine and spermine (which are involved in various types of abiotic stress tolerance), have been reported in many plant species. In this study, we identified 14 putative S-adenosylmethionine decarboxylase genes (GhSAMDC1-14) in upland cotton. Based on phylogenetic and expression analyses conducted under different abiotic stresses, we selected and transferred GhSAMDC3 into Arabidopsis thaliana. Compared to the wild type, transgenic plants displayed rapid growth and increases in average leaf area and leaf number of 52% and 36%, respectively. In transgenic plants, the germination vigor and rate were markedly enhanced under NaCl treatment, and the plant survival rate increased by 50% under 300 mM NaCl treatment. The spermidine content was significantly increased, possibly due to the synthesis of a series of PAs and oxidant and antioxidant genes, resulting in improved salinity tolerance in Arabidopsis. Various salinity resistance-related genes were upregulated in transgenic plants. Together, these results indicate that ectopic expression of GhSAMDC3 raised salinity tolerance by the accumulation of spermidine and activation of salinity tolerance-related genes in A. thaliana.

中文翻译：

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由于拟南芥中Spd含量的积累和耐盐相关基因的激活，GhSAMDC3的异位表达增强了耐盐性

多胺（PAs），特别是亚精胺和精胺（参与各种类型的非生物胁迫耐受性），已在许多植物物种中报道。在这项研究中，我们确定了14个假定的S-腺苷甲硫氨酸脱羧酶基因（GhSAMDC1 - 14）陆地棉。基于在不同非生物胁迫下进行的系统发育和表达分析，我们选择GhSAMDC3并将其转移到拟南芥中. 与野生型相比，转基因植物生长迅速，平均叶面积和叶数分别增加了 52% 和 36%。在转基因植株中，NaCl处理显着提高了发芽势和发芽率，300mM NaCl处理下植株成活率提高了50%。亚精胺含量显着增加，可能是由于合成了一系列 PA 以及氧化和抗氧化基因，导致拟南芥的耐盐性提高。各种耐盐相关基因在转基因植物中上调。总之，这些结果表明GhSAMDC3 的异位表达通过亚精胺的积累和耐盐相关基因的激活提高了耐盐性。拟南芥。