MicroRNA395 mediates regulation of sulfate accumulation and allocation in Arabidopsis thaliana
MicroRNA395 mediates regulation of sulfate accumulation and allocation in Arabidopsis thaliana
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DOI：
10.1111/j.1365-313x.2010.04216.x
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发表时间：
2010-06-01
期刊：
影响因子：
7.2
通讯作者：
Yu, Diqiu
中科院分区：
文献类型：
--
作者：
Liang, Gang;Yang, Fengxi;Yu, Diqiu
硫是植物生长发育所必需的大量营养素.硫酸盐是硫的主要来源，被植物根部吸收并运输到各种组织中进行同化。在硫酸盐限制期间，miR 395的表达显著上调。miR 395靶向两个基因家族，ATP硫酸化酶（由APS基因编码）和硫酸盐转运蛋白2;1（SULTR 2;1，也称为AST 68），这两个家族都参与硫酸盐代谢途径。它们的转录物在miR 395过表达的转基因拟南芥中受到强烈抑制，该转基因拟南芥在地上部而不是根部过度积累硫酸盐。APS 1敲除突变体积累的硫酸盐是野生型的两倍。通过构建APS 4-RNAi转基因植株，我们发现沉默APS 4基因也会导致硫酸盐的过量积累。即使miR 395过表达的转基因植物在芽中过度积累硫酸盐，它们也会表现出缺硫症状。此外，在miR 395过表达的植物中，硫酸盐从较老叶到较年轻叶的分布受损，类似于SULTR 2;1功能丧失突变体。aps 1 -1 sultr 2;1 APS 4-RNAi三重阻遏突变体表型模仿miR 395过表达植物。我们的研究表明miR 395分别通过靶向APS基因和SULTR 2;1基因参与硫酸盐积累和分配的调控。
P>Sulfur is a macronutrient that is necessary for plant growth and development. Sulfate, a major source of sulfur, is taken up by plant roots and transported into various tissues for assimilation. During sulfate limitation, expression of miR395 is significantly up-regulated. miR395 targets two families of genes, ATP sulfurylases (encoded by APS genes) and sulfate transporter 2;1 (SULTR2;1, also called AST68), both of which are involved in the sulfate metabolism pathway. Their transcripts are suppressed strongly in miR395-over-expressing transgenic Arabidopsis, which over-accumulates sulfate in the shoot but not in the root. APS1 knockdown mutants accumulate twice as much sulfate as the wild-type. By constructing APS4-RNAi transgenic plants, we found that silencing the APS4 gene also results in over-accumulation of sulfate. Even though miR395-over-expressing transgenic plants over-accumulate sulfate in the shoot, they display sulfur deficiency symptoms. Additionally, the distribution of sulfate from older to younger leaves is impaired in miR395-over-expressing plants, similar to a SULTR2;1 loss-of-function mutant. The aps1-1 sultr2;1 APS4-RNAi triply repressed mutants phenocopied miR395-over-expressing plants. Our research showed that miR395 is involved in the regulation of sulfate accumulation and allocation by targeting APS genes and SULTR2;1, respectively.