甘露醇-1-P脱氢酶转基因表达对转基因水稻幼苗抗盐性的影响

现已证实，在转基因烟草中超量合成并积累低分子量化合物，可以增强植物对包括盐渍在内的非生物逆境的抗性。这些低分子量化合物包括甘露醇、脯氨酸、果聚糖、甜菜碱、海藻糖和芒柄醇等。在大肠杆菌中甘露醇－１－Ｐ脱氢酶（ＥＣ１．１．１．１７），由ｍｔｌＤ基因编码并催化Ｄ－甘露醇的运输和利用〔２〕。然而，在转基因烟草（ＮｉｃｏｔｉａｎａｔａｂａｃｕｍＬ．）〔５〕和拟南芥（ＡｒａｂｉｄｏｐｓｉｓｔｈａｌｉａｎａＬ．）〔６〕中，ｍｔｌＤ转基因表达却导致甘露醇的合成和积累并对ＮａＣｌ处理产生很强的抗性。本研究用ｍｔｌ…

Transgene Expression of Mannitol-1-phosphate Dehydrogenase Enhanced the Salt-stress Tolerance of the Transgenic Rice Seedlings

It has been demonstrated that biosynthesis and accumulation of mannitol in plants are correlated with the salt-stress tolerance of the plants. In this study, a bacterial mtlD gene encoding mannitol-1-phosphate dehydrogenase was transformed into the rice genome and three independent transgenic lines (M2, M5 and M8) were obtained. The enzymatic activities of the three lines were 15.8 (M2), 46.2 (M5) and 11.4 (M8) respectively. In contrast to the non-transgenic rice plants, the mtlD-transgenic plants increased from 77% to 141% in shoot heights, and 17% to 50% in the fresh weights of shoots and roots.