Temporal expression of Anthocyanin1 gene reveals unique accumulation pattern of anthocyanins during different stages...

The Anthocyanin1 (A1) gene plays vital role in anthocyanin biosynthesis in maize. Here, accumulation patterns of anthocyanins and expression of A1 gene were analyzed during three stages of kernel development viz., 15-, 30-, and 45-days after pollination (DAP) among three wild-type (A1A1) and three mutant-type (a1a1) inbreds. Inbreds with dominant A1 allele produced anthocyanins, while inbreds with recessive a1 allele were colourless. Total anthocyanin (TA) ranged from 34.74 to 525.91 ppm. TA during 15-DAP was 64.21 ppm, while it increased to 258.20 and 442.30 ppm during 30- and 45-DAP, respectively. Cyanidin-3-glucoside (C3G), cyanidin 3-(6″-malonylglucoside) (C3MG), cyanidin-3,5-diglucoside (C3DG), pelargonidin-3-glucoside (P3G) and peonidin-3-glucoside (Pn3G) were different components of anthocyanins. Of these, C3G (60%) was the major anthocyanin, followed by C3MG (15%), P3G (10%), C3DG (9%) and Pn3G (6%) observed during kernel developmental stages. While, proportion of C3G and C3MG in TA increased, C3DG and P3G decreased during early to late stages, with Pn3G being nearly the same. Across stages, transcript levels of A1 was 9.8-fold higher over a1. The highest expression of A1 allele was observed at 30-DAP (2.073), whereas the lowest expression was recorded at 15-DAP (0.368). In contrast, expression level of a1 allele was highest at 45-DAP (0.136), while the lowest (0.093) was at 15-DAP. The inbred MGU-CL-A1-118 had the highest expression level of the A1 gene with maximum accumulation of TA. The transcript levels of A1 were positively correlated with TA (r = 0.502^**), C3G (r = 0.445^*) and C3MG (r = 0.816^**). The study provided insight into the regulation of anthocyanin biosynthesis in maize kernels.

The online version contains supplementary material available at 10.1007/s13205-025-04420-4.