A Rice cis-Natural Antisense RNA Acts as a Translational Enhancer for Its Cognate mRNA and Contributes to Phosphate Homeostasis and Plant Fitness
A Rice cis-Natural Antisense RNA Acts as a Translational Enhancer for Its Cognate mRNA and Contributes to Phosphate Homeostasis and Plant Fitness
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DOI：
10.1105/tpc.113.116251
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发表时间：
2013-10-01
期刊：
影响因子：
11.6
通讯作者：
Poirier, Yves
中科院分区：
文献类型：
--
作者：
Jabnoune, Mehdi;Secco, David;Poirier, Yves
顺式天然反义转录物（cis-NATs）在植物中广泛存在，通常与相关意义基因的下调有关。我们发现顺式nat正向调节水稻（Oryza sativa）中对磷酸盐稳态至关重要的蛋白质水平。PHOSPHATE1;水稻木质部磷酸化基因2 （PHO1;2）及其相关的顺式nat （PHO1;2）均受根和叶维管柱中活跃的启动子控制。PHO1；2启动子对植物的磷酸盐状态没有反应，顺式nat （PHO1;2）启动子在磷酸盐缺乏时被强烈上调。顺式nat （PHO1;2）和PHO1的表达；2蛋白在缺磷植株中升高，PHO1；2 mRNA水平保持稳定。通过RNA干扰下调顺式nat （PHO1;2）表达导致PHO1降低；2蛋白，破坏了磷酸盐从根到地上部的转移，降低了种子产量。trans中组成性过表达NAT（PHO1;2）导致PHO1的强烈表达；2、即使在磷酸盐充足的条件下。在所有条件下，PHO1的表达水平、序列和核输出均未发生变化；2 mRNA。然而，顺式nat （PHO1;2）的表达与PHO1；2和顺式nat （PHO1;2）朝向多体。这些发现揭示了cis-NAT（PHO1;2）在促进PHO1；2的翻译和影响磷酸盐稳态和植物适应性。
cis-natural antisense transcripts (cis-NATs) are widespread in plants and are often associated with downregulation of their associated sense genes. We found that a cis-NAT positively regulates the level of a protein critical for phosphate homeostasis in rice (Oryza sativa). PHOSPHATE1;2 (PHO1;2), a gene involved in phosphate loading into the xylem in rice, and its associated cis-NAT(PHO1;2) are both controlled by promoters active in the vascular cylinder of roots and leaves. While the PHO1;2 promoter is unresponsive to the plant phosphate status, the cis-NAT(PHO1;2) promoter is strongly upregulated under phosphate deficiency. Expression of both cis-NAT(PHO1;2) and the PHO1;2 protein increased in phosphate-deficient plants, while the PHO1;2 mRNA level remained stable. Downregulation of cis-NAT(PHO1;2) expression by RNA interference resulted in a decrease in PHO1;2 protein, impaired the transfer of phosphate from root to shoot, and decreased seed yield. Constitutive overexpression of NAT(PHO1;2) in trans led to a strong increase of PHO1;2, even under phosphate-sufficient conditions. Under all conditions, no changes occurred in the level of expression, sequence, or nuclear export of PHO1;2 mRNA. However, expression of cis-NAT(PHO1;2) was associated with a shift of both PHO1;2 and cis-NAT(PHO1;2) toward the polysomes. These findings reveal an unexpected role for cis-NAT(PHO1;2) in promoting PHO1;2 translation and affecting phosphate homeostasis and plant fitness.