JXB Advance Access published online on December 1, 2008
Journal of Experimental Botany, doi:10.1093/jxb/ern298
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RESEARCH PAPER |
Proton pump OsA8 is linked to phosphorus uptake and translocation in rice

1State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
2College of Agronomy, Hainan University, Danzhou, Hainan, 571737, China
To whom correspondence should be addressed: E-mail: ghxu{at}njau.edu.cn
The plasma membrane (PM) proton pump ATPases (H+-ATPases) are involved in almost all aspects of biology. They are plant specific and several members of this family are supposed to play a key role in nutrient acquisition. At present, only some members of this gene family in plants have been characterized. However, no nutrient uptake associated H+-ATPase gene in rice has been functionally analysed. It is reported here that OsA8, a typical PM H+-ATPases gene that was predominantly expressed in roots of rice, is down-regulated by nutrient deficiency. The Osa8 mutant had a relatively smaller size and root to shoot biomass ratio, but higher ATPase activity than its wild-type counterparts under phosphorus (P) starvation conditions. Knockout of OsA8 affected the expression of several OsA genes and the high affinity phosphate transporter, OsPT6, and resulted in a higher P concentration in the roots and a lower amount of P in the shoots. These analyses demonstrate that OsA8 not only influences the uptake of P by roots, but also the translocation of P from the roots to the shoots in rice.
Key words: Knockout mutant, plasma membrane H+-ATPase, Oryza sativa, phosphorus, Tos17 retrotransposon, phosphate transporter
* These authors contributed equally to this article
Received 25 July 2008; Revised 29 October 2008 Accepted 31 October 2008