Temperature effects on the wx protein level and amylose content in the endosperm of rice

To investigate the gene regulation at the waxy locus and the effects of the gene product called Wx protein on amylose content in endosperm starch, two rice strains, Shiokari and its low-amylose mutant, were compared with regard to the levels of Wx protein and amylose under different conditions. The mutant showed a reduced level of Wx protein bound to starch granules compared to Shiokari, indicating that the gene carried by the mutant regulates the Wx protein level as well as amylose content. In addition, lower temperature during grain development increased the amount of Wx protein as well as amylose, suggesting that the genic expression at the wx locus is influenced by temperature.