NUTRITIONAL QUALITY UPGRADING OF INDIGENOUSLY DEVELOPED RICE MUTANT THROUGH EXPLORATION OF PHYTIC ACID AND AMYLOSE REGULATORY GENES

Phytic acid and amylose in rice food play an essential role in human health. The best-practiced approach is necessary for nutritional quality improvement of rice grain. The mutational breeding approach and chemical treatment are powerful methods to enhance rice quality by managing the concentration of phytic acid and amylose contents. The analysis of glycemic index and amylose contents is also significant to reduce the risk of diseases. The present research investigates nutrient quality such as phytic acid and amylose content in the developed rice mutant (PBEF20). The developed mutant shows a 50% reduction in phytic acid with a 37.73% increment in amylose contents compared to the control i.e., untreated sample. The Inositol phosphate kinase (IPK-1) and ABC-2 type transporter domain-containing protein differentially downregulated in the early flowering mutant. IPK-1 gene is responsible for converting inositol 5-phosphate (IP5) to inositol 6-phosphate (IP6). The ABC-2 type genes are vacuolar transporters to transport the phosphate that assists in synthesizing phytic acid. The identified genes, including beta-amylase and chloroplast precursor, regulate various functions in the starch sucrose metabolic reference pathway, and their upregulation controls the expression of downstream genes involved in amylose synthesis. The expressions of the genes responsible for phytic acid, starch synthesis, and nutrient reservoir activity during the rice maturity stage are examined using microarray technology to track gene regulation, while the grain filling pattern of the amylose mutant is analyzed using scanning electron microscopy (SEM). Results indicate significant variation in carbohydrate granules size and starch compactness.