氮素是作物必需的營養(yǎng)元素之一,，對作物的生命活動和產(chǎn)量的形成具有重要意義,。近年來，隨著農(nóng)田氮肥的過量施用,，對環(huán)境造成的污染也日益加重,。提高作物氮利用效率，是農(nóng)業(yè)可持續(xù)發(fā)展的關(guān)鍵,，是第二次“綠色革命”的目標和要求,。
中科院華南植物園植物營養(yǎng)生理研究組博士研究生方中明在張明永研究員的指導下，發(fā)現(xiàn)在水稻中超表達OsPTR9基因可促進水稻對銨態(tài)氮的吸收,，同時在低施氮肥的條件下可促進水稻增產(chǎn),。研究顯示：OsPTR9基因的表達受外界氮源和光晝夜節(jié)律的調(diào)節(jié),。營養(yǎng)生長階段，超表達OsPTR9能夠促進銨的吸收,，增加側(cè)根的發(fā)生,，提高水稻生物量。生殖生長階段,，超表達OsPTR9能夠提高氮再動員和重新分配的運輸效率,，最終提高水稻產(chǎn)量。在OsPTR9降低表達的突變體和RNAi植株中指標和表型相反,。在不施氮肥的種植下,，超標達OsPTR9的水稻的產(chǎn)量比對照增幅最大，達到18.6%,；正常施用氮肥下,，超表達OsPTR9的水稻兩個株系比對照增產(chǎn)7.2%和8.1%；施用銨態(tài)氮肥,，有利于超表達水稻獲得較高的產(chǎn)量,。研究結(jié)果初步表明：OsPTR9在促進氮利用效率和水稻分子育種上具有潛在的應用價值，該基因超表達后能夠提高土壤中氮的利用,，促進水稻生長并提高產(chǎn)量,。
該研究成果已申請一項國家發(fā)明專利（專利號：201110022987.3），申請并公開一項國際發(fā)明專利(專利號：PCT/CN2011/082100),。同時已在國際學術(shù)刊物Plant Biotechnology Journal(doi: 10.1111/pbi.12031,，IF2011= 5.442)上發(fā)表。(生物谷Bioon.com)
DOI: 10.1111/pbi.12031
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PMID:
Altered expression of the PTR/NRT1 homologue OsPTR9 affects nitrogen utilization efficiency, growth and grain yield in rice
Zhongming Fang1,2,†, Kuaifei Xia1,3, Xin Yang1,2, Marianne Suter Grotemeyer4, Stefan Meier4, Doris Rentsch4, Xinlan Xu3, Mingyong Zhang1,3,*
The plant PTR/NRT1 (peptide transporter/nitrate transporter 1) gene family comprises di/tripeptide and low-affinity nitrate transporters; some members also recognize other substrates such as carboxylates, phytohormones (auxin and abscisic acid), or defence compounds (glucosinolates). Little is known about the members of this gene family in rice (Oryza sativa L.). Here, we report the influence of altered OsPTR9 expression on nitrogen utilization efficiency, growth, and grain yield. OsPTR9 expression is regulated by exogenous nitrogen and by the day-night cycle. Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake, promotion of lateral root formation and increased grain yield. On the other hand, down-regulation of OsPTR9 in a T-DNA insertion line (osptr9) and in OsPTR9-RNAi rice plants had the opposite effect. These results suggest that OsPTR9 might hold potential for improving nitrogen utilization efficiency and grain yield in rice breeding.
