Correlation of carotenoid accumulation and expression pattern of carotenoid biosynthetic pathway genes in Indian wheat varieties

Abstract

Carotenoids are the source of antioxidants and precursor for vitamin A in humans. Several wheat varieties are cultivated in India, but limited information on carotenoid content in grains hamper their nutritional impact in society. A total of 30 Indian hexaploid wheat varieties were subjected to carotenoid profiling in mature seeds. Lutein was the major carotenoid followed by zeaxanthin and β-carotene. Studies in two contrasting wheat varieties, VL907 (1.63 μg/g) and K8962 (0.53 μg/g) revealed varying expression pattern of nine carotenoid biosynthesis pathway genes during the seed developmental stages. The higher expression of TaLCYB suggests a prominent role in enhanced β-carotene content in seed development stages of VL907. While higher expression of TaLCYE inversely correlated with β-carotene deposition in K8962. A strong negative correlation of TaBCH1 and TaBCH2 expression was observed with all carotenoids, except zeaxanthin in K8962, whereas a weak negative correlation of TaPSYs with all major carotenoids was found in both K8962 and VL907. Hence, the results suggest that the carotenoids accumulation in the seed of wheat varieties could be regulated by the expression patterns of TaLCYB, TaPSYs and TaBCHs genes. The present study facilitates the functional characterization of these genes to gain more understanding of their role in carotenoid accumulation in wheat.