Global gene expression analysis of transgenic, mannitol-producing, and salt-tolerant Arabidopsis thaliana indicates widespread changes in abiotic and biotic stress-related genes.
Global gene expression analysis of transgenic, mannitol-producing, and salt-tolerant Arabidopsis thaliana indicates widespread changes in abiotic and biotic stress-related genes.
复制标题
DOI：
10.1093/jxb/err130
复制
发表时间：
2011-10
影响因子：
6.9
通讯作者：
Loescher W
中科院分区：
文献类型：
--
作者：
Chan Z;Grumet R;Loescher W
甘露醇是一种假定的渗透保护剂，有助于几种物种的耐盐性。经芹菜甘露糖-6-磷酸还原酶（M6PR）基因转化的拟南芥耐盐性（100 mM NaCl）显著高于野生型（WT），表现为盐害减少、营养生长抑制减少、种子产量增加。当200 mM NaCl处理时，转化体不产生种子，但会产生螺栓，表现出更少的黄化/坏死，存活率和干重都比WT高。没有盐处理，M6PR对生长和表型没有影响，但2272个基因的表达水平发生了改变。在盐存在的情况下，M6PR和WT植株之间的差异要小得多（1039），这表明M6PR预先调节了植株对胁迫的适应。以前的研究表明甘露醇是一种渗透保护剂，但甘露醇的含量总是很低，可能不足以发挥渗透保护剂的作用。本研究通过转录组分析发现，M6PR转基因通过上调ABA受体基因（PYL4、PYL5和PYL6）和下调蛋白磷酸酶2C基因（ABI1和ABI2）激活下游脱落酸（ABA）通路。在M6PR转基因系中，与氧化还原和细胞壁强化途径相关的转录物也有所增加。这些数据表明，甘露醇增强的应激耐受性至少部分是由于多种应激诱导基因的表达增加。
Mannitol is a putative osmoprotectant contributing to salt tolerance in several species. Arabidopsis plants transformed with the mannose-6-phosphate reductase (M6PR) gene from celery were dramatically more salt tolerant (at 100 mM NaCl) as exhibited by reduced salt injury, less inhibition of vegetative growth, and increased seed production relative to the wild type (WT). When treated with 200 mM NaCl, transformants produced no seeds, but did bolt, and exhibited less chlorosis/necrosis and greater survival and dry weights than the WT. Without salt there were no M6PR effects on growth or phenotype, but expression levels of 2272 genes were altered. Many fewer differences (1039) were observed between M6PR and WT plants in the presence of salt, suggesting that M6PR pre-conditioned the plants to stress. Previous work suggested that mannitol is an osmoprotectant, but mannitol levels are invariably quite low, perhaps inadequate for osmoprotectant effects. In this study, transcriptome analysis reveals that the M6PR transgene activated the downstream abscisic acid (ABA) pathway by up-regulation of ABA receptor genes (PYL4, PYL5, and PYL6) and down-regulation of protein phosphatase 2C genes (ABI1 and ABI2). In the M6PR transgenic lines there were also increases in transcripts related to redox and cell wall-strengthening pathways. These data indicate that mannitol-enhanced stress tolerance is due at least in part to increased expression of a variety of stress-inducible genes.