Effect of NaCl stress and supplemental CaCl2 on carotenoid accumulation in germinated yellow maize kernels.

Germinated edible seeds and sprouts are becoming increasingly common in the human diet because they are rich in bioactive compounds and antioxidants and are highly nutritious. In this study, the effects of NaCl stress and supplemental CaCl2 on carotenoid accumulation, antioxidant capacity and expression of key enzymes in yellow maize kernels were investigated. The results showed that the lutein and zeaxanthin contents increased with NaCl treatment, and further increased with supplemental CaCl2. Additionally, germinated yellow maize kernels showed increased antioxidant capacity in response to NaCl and CaCl2. The transcript levels of carotenogenic genes ZmPSY and ZmCYP97C were upregulated and the expression levels of ZmLCYB and ZmBCH1 were downregulated under NaCl stress. The expression of all key carotenogenic genes was upregulated by CaCl2 supplementation. These results suggested that NaCl and CaCl2 contribute to carotenoid accumulation via increased expression of related carotenogenic genes and increased antioxidant capacity in germinated yellow maize kernels.