Manipulation Of Amylose Content In Rice By Transgenic Approach

In order to improve the grain quality of rice by genetic engineering, three Ti-plasmid. p13W2, p13W4 and p13B4, containing the sense waxy gene, antisense waxy gene and antisense sbel gene respectively, were constructed and introduced into various rice cultivars, both of Japonica and Indica, via Agrobacterium. Many transgenic rice lines were produced and the amylose content in the seeds of these transgenic rice plants were carefully analyzed. In addition, for improving the efficiency of transformation mediated by Agrobacterium. the suitable medium for callus induction and suitable induction culture period for transformation were also studied. The results were as follows.1. Callus was more efficiently induced from immature embryos in the MH medium, which contains the MS basal composition, than in other media, For the indica rice viariety Xieqingzao B, 8-days old calli derived from immature embryos were the suitable material for Agrobacterium-mediated transformation.2. Many transgenic rice lines, transformed with the three different genes respectively, were regenerated, and the integration of these transgenes in the transformed plants was confirmed by PCR technique. The GUS activity was also detected in the leaf of some transgenic plants, which had been transformed with the Wx-GUS fusion gene (p13W4).3. The amylose content in the endosperm of mature seeds from primary TO transgenic plants was analyzed. The results showed that the amylose content in the endosperm of some transgenic seeds was altered (i.e. reduced or increased), and the changed level differed in various transgenic plants, according to the transgenes and rice varieties.4. Genetic analysis of some T1 transgenic plants showed that the transgenes were inherited into the progenies as the Mendelian fasion in most of the cases.