SOM encodes a nucleus-localized CCCH-type zinc finger protein and negatively regulates seed germination in Arabidopsis thaliana. We have previously demonstrated that ectopic expression of Sl ABI3, an important transcription factor in abscisic acid（ABA） signaling pathway, resulted in alteration of Sl SOM expression patterns in both leaf and seed of tomato. In this study, we aimed to elucidate the function of tomato Sl SOM in regarding to seed germination and seedling development. Here, we constructed Sl SOM over-expression vector p BI121-SOM driven by Ca MV 35 S promoter, and the recombinant plasmid was incorporated into wild-type tomato by the method of Agrobacterium tumefaciens-mediated transformation. The result showed that over-expression of Sl SOM conferred enhanced responses to exogenous ABA application during seed germination and seedling development. In addition, ectopic expression of Sl SOM resulted in the alteration of expression level of ABA/GA（gibberellins） metabolic genes, such as Sl ABA1, Sl CYP707A1, Sl GA3ox2, and Sl GA2ox4, in both leaf and seed. The ABA anabolic gene Sl ABA1 and the GA catabolic gene Sl GA2ox4 were up-regulated while the ABA catabolic gene Sl CYP707A1 and the GA anabolic gene Sl GA3ox2 were down-regulated. Compared to wild type, the expression level of Sl ABI5 was increased by about 40–50% in transgenic seeds while adding exogenous ABA treatment. These results support the notion that Sl SOM inhibits seed germination by regulating ABA/GA metabolic genes and Sl ABI5 expression in Solanum lycopersicum.
SUN Xiao-chunGAO Yong-fengZHANG NingLI Hui-rongYANG Shu-zhangLIU Yong-sheng
研究通过对番茄MSI2-like蛋白序列与其它模式植物的蛋白序列进行同源性比对,发现番茄MSI2-like与马铃薯的同源性最高;另外还预测了其蛋白质的理化性质及三级结构.酵母双杂交实验证明,MSI2-like与UV-Damaged DNA Binding Protein 1(DDB1)具有相互作用.同时,利用RNA干涉技术构建植物双元载体,农杆菌介导法转化番茄得到转基因植株,该转基因植株在干旱胁迫条件下有一定的抗旱功能.再利用实时荧光定量PCR分析MSI2-like基因表达的组织差异性,发现它在各个组织中都表达,但是在生殖器官花中的表达量明显较其他组织高.
