把鹽堿地變成良田沃土,，是人類(lèi)自古至今的夢(mèng)想,，如今這個(gè)夢(mèng)想離現(xiàn)實(shí)又近了一大步。近日,，華東師范大學(xué)夏濤教授的課題組,，通過(guò)基因改組技術(shù)創(chuàng)造了一種新的“鈉氫逆向轉(zhuǎn)運(yùn)蛋白”，轉(zhuǎn)入并表達(dá)這種新基因的植物,，能夠在高鹽環(huán)境下正常生長(zhǎng),，這也就意味著這種轉(zhuǎn)基因植物有望成為鹽堿地的 “死敵”,。
夏濤教授告訴記者，目前全世界土地的1/4到1/3為鹽漬化土壤,，大約20%的耕種土地和接近一半的灌溉土地都不同程度受到了鹽漬化危害,。植物通過(guò)根吸收水分和養(yǎng)料，也會(huì)把鹽堿成分運(yùn)輸?shù)秸麄€(gè)植物體,。如果吸收到體內(nèi)的鹽堿成分濃度過(guò)高,，植物就會(huì)死去，這也是在鹽堿地上植物不容易生長(zhǎng)的原因,。如何培育能夠在鹽堿地上正常生長(zhǎng)的植物特別是培育高耐鹽性的轉(zhuǎn)基因工程植物,，是進(jìn)行鹽堿地改良的根本出路，也是目前學(xué)術(shù)界的研究重點(diǎn),。
夏濤教授課題組決定以酵母突變體為高通量的篩選體系,，通過(guò)基因改組技術(shù)強(qiáng)化鈉氫逆向轉(zhuǎn)運(yùn)蛋白的搬運(yùn)能力，經(jīng)過(guò)一系列的實(shí)驗(yàn),，取得了成功,。數(shù)據(jù)顯示，這種新創(chuàng)造的鈉氫逆向轉(zhuǎn)運(yùn)蛋白轉(zhuǎn)運(yùn)鹽分的能力比野生的鈉氫逆向轉(zhuǎn)運(yùn)蛋白提高了約1倍?，F(xiàn)在,，他們還將該基因植入了擬南芥中，結(jié)果發(fā)現(xiàn)擬南芥在鹽堿環(huán)境中的生存能力大大提高,。他的最新研究成果剛剛在國(guó)際著名學(xué)術(shù)期刊《生物化學(xué)雜志》在線發(fā)表,，目前還申請(qǐng)了中國(guó)國(guó)家發(fā)明專(zhuān)利和國(guó)際PCT專(zhuān)利。
目前,，夏濤課題組正在改良這種基因,，繼續(xù)提升它的活力，同時(shí)開(kāi)展改良基因的工程化育種,。該項(xiàng)成果具有廣闊的應(yīng)用前景,。(生物谷Bioon.com)
生物谷推薦原文出處：
JBC doi: 10.1074/jbc.M109.073783
A novel plant vacuolar Na+/H+ antiporter gene evolved by DNA shuffling confers improved salt tolerance in yeast
Kai Xu1, Hui Zhang1, Eduardo Blumwald2 and Tao Xia1,*
Plant vacuolar Na+/H+ antiporters play important roles in maintaining cellular ion homeostasis and mediating the transport of Na+ out of the cytosol and into the vacuole. Vacuolar antiporters have been shown to play significant roles in salt tolerance, however the relatively low Vmax of the Na+/H+ exchange of the Na+/H+ antiporters identified could limit its application in the molecular breeding of salt tolerant crops. In this study, we applied DNA shuffling methodology to generate and recombine the mutations of Arabidopsis thaliana vacuolar Na+/H+ antiporter gene AtNHX1. Screening using a large scale yeast complementation system identified AtNHXS1, a novel Na+/H+ antiporter. Expression of AtNHXS1 in yeast showed that the antiporter localized to the vacuolar membrane and that its expression improved the tolerance of yeast to NaCl, KCl, LiCl and hygromycin B. Measurements of the ion transport activity across the intact yeast vacuole demonstrated that the AtNHXS1 protein showed higher Na+/H+ exchange activity and a slightly improved K+/H+ exchange activity.
