Expression of betaine aldehyde dehydrogenase gene and salinity tolerance in rice transgenic plants

Betaine as one of osmolytes plays an important role in osmoregulation of most high plants. Betaine aldehyde dehydrogenase (BADH) is the second enzyme involved in betaine biosynthesis. The BADH gene from a halophite,Atriplex hortensis, was transformed into rice cultivars by bombarment method. Totally 192 transgenic rice plants were obtained and most of them had higher salt tolerance than controls. Among transgenic plants transplanted in the saline pool containing 0.5% NaCl in a greenhouse, 22 survived. 13 of which set seeds, and the frequency of seed setting was very low, only 10%. But the controls could not grow under the same condition. The results of BADH activity assay and Northern blot showed that the BADH gene was integrated into chromosomes of transgenic plants and expressed.