Differential regulation at the wx locus of rice

点击翻译按钮获取中文摘要

The waxy (wx) locus in rice, which specifies a major starchgranule-bound protein called Wx protein, is genetically well characterized. Our previous works revealed that in addition to wx, there are at least two nonwaxy alleles at the wx locus which regulate the amounts of the gene product as well as amylose in different ways. The present study was carried out to get more insights on to what extent the allelic differentiation at the wx locus is important for diversification in amylose content observed among nonwaxy rice cultivars. The results confirmed that among naturally occurring variants tested, amylose content is mainly determined by the allelic changes at the wx locus. In addition, the amount of the gene product was affected by effects of temperatures, modifiers and the gene dosage in a similar manner which the amylose content was affected. Those effects were expected to lead the amylose content to a polygenic trait in segregating populations as often reported in rice, even though the amylose content was simply controlled by the amount of Wx protein. The allelic differentiation at the wx locus was also discussed in relation to the evolutionary significances of the gene regulation.