MUTATIONS IN STARCH BIOSYNTHESIS GENES LEADING TO HIGH FIBER AND RESISTANT STARCH EXPRESSION IN RICE ENDOSPERM

摘要

The present invention discloses the mutations in the starch synthase genes of Tx2 mutant rice that are associated with enhanced dietary fiber and resistant starch levels in the endosperm. The increased level of dietary fiber and resistant starch in rice results in low glycemic index with a value of value of 51.2+5.2 and hence these rice varieties are of great demand for diabetic population. The mutations in starch synthase genes target the structural modification of amylopectin instead of increasing the amylose content without affecting the cooking quality of the rice grains. The mutation in SSIIa gene is also associated with reduced chain elongation in L form of amylopectin such that amylopectin chain length can be manipulated in indica varieties of rice.