Molecular cloning, functional characterization and expression of potato (Solanum tuberosum) 1-deoxy-D-xylulose 5-phosphate synthase 1 (StDXS1) in response to Phytophthora infestans
Molecular cloning, functional characterization and expression of potato (Solanum tuberosum) 1-deoxy-D-xylulose 5-phosphate synthase 1 (StDXS1) in response to Phytophthora infestans
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DOI：
10.1016/j.plantsci.2015.12.001
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发表时间：
2016-02-01
期刊：
影响因子：
5.2
通讯作者：
Daayf, Fouad
中科院分区：
文献类型：
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作者：
Henriquez, Maria Antonia;Soliman, Atta;Daayf, Fouad
1-脱氧-n-木酮糖5-磷酸合酶（DXS）催化类异戊二烯生物合成中质体2C-甲基-D-β-4-磷酸（DOXP-MEP）途径的起始步骤。本研究克隆了马铃薯DXS基因的全长cDNA，命名为StDXS 1。StDXS 1 cDNA编码719个氨基酸残基，分子量为77.8 kDa，在马铃薯基因组中以一个拷贝存在。系统发育分析和蛋白质序列比对分配StDXS 1与DXS同源物从密切相关的物种，并表现出同源结构域的身份与已知的DXS蛋白从其他植物物种。晚疫病症状发生在平行的减少StDXS 1转录水平，这可能与类异戊二烯的水平，有助于植物保护病原体。亚细胞定位表明StDXS 1靶向合成类异戊二烯的叶绿体。表达StDXS 1的拟南芥表现出比野生型对照更高的类胡萝卜素和叶绿素积累。与对照植物相比，在转基因DXS系中检测到较低水平的阿坝和GA，这反映了转基因DXS系的较高发芽率。JA或SA含量未检测到变化。DOXP-MEP途径中选定的下游基因，尤其是GGPPS基因，在转基因系中上调。(C)2015爱思唯尔爱尔兰有限公司版权所有。
1-Deoxy-n-xylulose 5-phosphate synthase (DXS) catalyzes the initial step of the plastidial 2C-methyl-D-erythritol-4-phosphate (DOXP-MEP) pathway involved in isoprenoid biosynthesis. In this study, we cloned the complete cDNA of potato DXS gene that was designated StDXS1. StDXS1 cDNA encodes for 719 amino acid residues, with MW of 77.8 kDa, and is present in one copy in the potato genome. Phylogenetic analysis and protein sequence alignments assigned StDXS1 to a group with DXS homologues from closely related species and exhibited homodomain identity with known DXS proteins from other plant species. Late blight symptoms occurred in parallel with a reduction in StDXS1 transcript levels, which may be associated with the levels of isoprenoids that contribute to plant protection against pathogens. Subcellular localization indicated that StDXS1 targets the chloroplasts where isoprenoids are synthesized. Arabidopsis expressing StDXS1 showed a higher accumulation of carotenoids and chlorophyll as compared to wild type controls. Lower levels of ABA and GA were detected in the transgenic DXS lines as compared to control plants, which reflected on higher germination rates of the transgenic DXS lines. No changes were detected in JA or SA Contents. Selected downstream genes in the DOXP-MEP pathway, especially GGPPS genes, were up-regulated in the transgenic lines. (C) 2015 Elsevier Ireland Ltd. All rights reserved.