Suppression of OsMADS7 in Rice Endosperm Stabilizes Amylose Content under High Temperature Stress

High temperature alters the amylose content of rice, leading to mature grains with poor eating quality. Despite this, only a few genes/loci involved in this process have been studied and the mechanisms of this process remain unclear. Hua Zhang from the Zhejiang Academy of Agricultural Sciences, along with his team, identified the floral organ identity gene, OsMADS7, involved in stabilizing rice amylose content at high temperatures.

OsMADS7 was greatly induced by high temperature at the early filling stage. Suppression of OsMADS7 stabilizes amylose content under high temperature stress, but also results in low spikelet fertility. However, rice plants with both stable amylose content at high temperature and normal spikelet fertility can be obtained by specifically suppressing OsMADS7 in endosperm.

GBSSI is the major enzyme responsible for amylose biosynthesis. A low filling rate and high expression of GBSSI were detected in OsMADS7 RNAi plants at high temperature, which may be correlated with stabilized amylose content in these transgenic seeds under high temperature.

Specific suppression of OsMADS7 in the endosperm could improve the stability of rice amylose content at high temperature, and such materials may be a valuable genetic resource for breeding rice with elite thermal resistance.

For more information, read the article in Plant Biotechnology Journal.