A Rice cis-Natural Antisense RNA Acts as a Translational Enhancer for Its Cognate mRNA and Contributes to Phosphate Homeostasis and Plant Fitness

作者：Jabnoune, Mehdi; Secco, David; Lecampion, Cecile; Robaglia, Christophe; Shu, Qingyao; Poirier, Yves^*

来源：Plant Cell, 2013, 25(10): 4166-4182.

DOI：10.1105/tpc.113.116251

• GENOME-WIDE ANALYSIS
• NONCODING RNAS
• ARABIDOPSIS-THALIANA
• ENDOGENOUS SIRNAS
• GENE-EXPRESSION
• TRANSCRIPTS
• PHO1
• IDENTIFICATION
• CHROMATIN
• REVEALS

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.

• 出版日期2013-10
• 单位浙江大学