南京農(nóng)業(yè)大學(xué)的研究人員通過轉(zhuǎn)基因手段和生物化學(xué)及生物物理方法,，研究揭示了水稻中兩個重要的磷酸鹽轉(zhuǎn)運蛋白基因的作用及其動力學(xué)特征,。相關(guān)成果近日在國際植物學(xué)著名學(xué)術(shù)期刊《植物學(xué)雜志》（The Plant Journal）在線發(fā)表。
領(lǐng)導(dǎo)這一研究的是南京農(nóng)業(yè)大學(xué)的徐國華教授,，其于2000年在以色列耶路撒冷希伯來大學(xué)（The Hebrew University of Jerusalem）獲得博士學(xué)位,，曾在以色列國家科學(xué)院（WEIZMANN）進行博士后研究。徐國華主持的作物養(yǎng)分資源高效利用的生物學(xué)途徑課題得到了 “973”項目資助,。
磷是植物生長發(fā)育所必需的三大營養(yǎng)元素之一,。磷素被植物吸收和“運輸”依賴于植物體內(nèi)各種各樣的磷素的“挑夫”———磷酸鹽轉(zhuǎn)運蛋白。但不同的“挑夫”是怎樣工作的,，目前植物營養(yǎng)學(xué)界一直在探索,。研究人員通過轉(zhuǎn)基因手段和生物化學(xué)及生物物理方法，研究揭示了水稻中兩個重要的磷酸鹽轉(zhuǎn)運蛋白基因的作用及其動力學(xué)特征,。
據(jù)論文第一作者,、南京農(nóng)大在校博士生艾鵬慧介紹，由于土壤中的有效磷含量很低,，植物自身就會通過改變根的形態(tài)和結(jié)構(gòu)來產(chǎn)生大量根毛,、側(cè)根、排根以及分泌有機酸,、磷酸酶等方式來盡可能地提高土壤中磷的有效性,。這些磷素的吸收和利用都要借助于植物體內(nèi)的“磷酸鹽轉(zhuǎn)運蛋白”來完成。根據(jù)對磷的吸收能力,，學(xué)界把磷酸鹽轉(zhuǎn)運蛋白分為高親和力轉(zhuǎn)運蛋白與低親和力轉(zhuǎn)運蛋白,。（生物谷Bioon.com）
生物谷推薦原始出處：
The Plant Journal，doi: 10.1111/j.1365-313X.2008.03726.x,，Penghui Ai,，Guohua Xu
Two rice phosphate transporters, OsPht1;2 and OsPht1;6, have different functions and kinetic properties in uptake and translocation
Penghui Ai 1, , Shubin Sun 1, , Jianning Zhao 1, , Xiaorong Fan 1 , Weijie Xin 1 , Qiang Guo 1 , Ling Yu 2 , Qirong Shen 1 , Ping Wu 3 , Anthony J. Miller 4 and Guohua Xu 1,*
1 State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China ,
2 The Center for Cell and Molecular Signaling, School of Medicine, Emory University, 30322 USA ,
3 State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310029, China , and
4 Centre for Soils and Ecosystem Function, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
Plant phosphate (Pi) transporters mediate the uptake and translocation of this nutrient within plants. A total of 13 sequences in the rice (Oryza sativa) genome can be identified as belonging to the Pi transporter (Pht1) family. Here, we report on the expression patterns, biological properties and the physiological roles of two members of the family: OsPht1;2 (OsPT2) and OsPht1;6 (OsPT6). Expression of both genes increased significantly under Pi deprivation in roots and shoots. By using transgenic rice plants expressing the GUS reporter gene, driven by their promoters, we detected that OsPT2 was localized exclusively in the stele of primary and lateral roots, whereas OsPT6 was expressed in both epidermal and cortical cells of the younger primary and lateral roots. OsPT6, but not OsPT2, was able to complement a yeast Pi uptake mutant in the high-affinity concentration range. Xenopus oocytes injected with OsPT2 mRNA showed increased Pi accumulation and a Pi-elicited depolarization of the cell membrane electrical potential, when supplied with mM external concentrations. Both results show that OsPT2 mediated the uptake of Pi in oocytes. In transgenic rice, the knock-down of either OsPT2 or OsPT6 expression by RNA interference significantly decreased both the uptake and the long-distance transport of Pi from roots to shoots. Taken together, these data suggest OsPT6 plays a broad role in Pi uptake and translocation throughout the plant, whereas OsPT2 is a low-affinity Pi transporter, and functions in translocation of the stored Pi in the plant.
