Proline accumulation and salt-stress-induced gene expression in a salt-hypersensitive mutant of arabidopsis
Proline accumulation and salt-stress-induced gene expression in a salt-hypersensitive mutant of arabidopsis
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DOI：
10.1104/pp.114.2.591
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发表时间：
1997-06-01
期刊：
影响因子：
7.4
通讯作者：
Zhu, JK
中科院分区：
文献类型：
--
作者：
Liu, JP;Zhu, JK
拟南芥sos1突变体对NaCl胁迫的敏感性是野生型拟南芥的20倍以上。由于脯氨酸（Pro）通常被认为在植物耐盐性中具有重要作用，因此比较了sos1突变体和野生型在NaCl胁迫下积累Pro的能力，并且sos1突变体植物比野生型积累更多的Pro。P5CS基因，催化Pro生物合成的限速步骤，诱导盐胁迫的sos1比野生型更高的水平。虽然有缺陷的高亲和力K吸收系统中sos1导致K缺乏，抑制NaCl处理的植物生长，这种减少是不是一个足够的信号Pro积累和P5CS基因表达。并非所有盐胁迫诱导的基因在sos1中都有较高的表达水平。AtPLC和RD29A，分别编码磷脂酶C同源物和一个假定的保护蛋白，表达水平是相同的sos1在野生型。然而，AtMYB的表达，它编码一个假定的转录因子，诱导盐胁迫在sos1更高的revel。因此，SOS 1基因产物对P5 CS和AtMYB的表达起负调节作用，但对AtPLC和RD 29 A的表达没有影响。
The sos1 mutant of Arabidopsis thaliana is more than 20 times more sensitive to NaCl stress than wild-type Arabidopsis. Because proline (Pro) is generally thought to have an important role in plant salt tolerance, the sos1 mutant and the wild type were compared with respect to their capacity to accumulate Pro under NaCl stress, and sos1 mutant plants accumulated more Pro than the wild type. The P5CS gene, which catalyzes the rate-limiting step in Pro biosynthesis, is induced by salt stress to a higher lever in sos1 than in the wild type. Although a defective high-affinity K uptake system in sos1 causes K deficiency and inhibits growth in NaCl-treated plants, this decrease is not a sufficient signal for Pro accumulation and P5CS gene expression. Not all salt-stress-induced genes have a higher level of expression in sos1. The expression levels of AtPLC and RD29A, which encode a phospholipase C homolog and a putative protective protein, respectively, are the same in sos1 as in the wild type. However, the expression of AtMYB, which encodes a putative transcriptional factor, is induced to a much higher revel by salt stress in sos1. Thus, the SOS1 gene product serves as a negative regulator for the expression of P5CS and AtMYB, but has no effect on AtPLC and RD29A expression.