Comparative transcriptome analysis reveals mechanisms of folate accumulation in maize grains

Two maize inbred lines, DAN3130 and JI63, with different patterns of folate accumulation and different total folate contents in mature kernels were used to investigate the transcriptional regulation of folate metabolism during late stages of kernel formation by comparative transcriptome analysis; The fresh kernel samples of each inbred line were collected on DAP 24, DAP 35 days, respectively. Mature kernel samples were harvested after all the plants turned yellow. Three biological replicates of each sample were collected, and total RNA with high quality was pooled and sent for sequencing. Total RNA of high quality was pooled for transcriptome analysis, and raw RNA-seq data of DAP 24, DAP35 and mature kernels for both two inbred lines were obtained. The folate accumulation during DAP 24 to mature kernels could be controlled by circumjacent pathways of folate biosynthesis, such as pyruvate metabolism, glutamate metabolism and serine/glycine metabolism. In addition, the folate variation between these two inbred lines was related to those genes among folate metabolism, such as genes in the pteridine branch, ?-ABA branch, serine/THF/5-M-THF cycle and the conversion of tetrahydrofolate monoglutamate to tetrahydrofolate polyglutamate; The findings provided insight into folate accumulation mechanisms during maize kernel formation to promote folate biofortification. Overall design: Examination of 2 different maize inbred lines of kernel on DAP 24, DAP 35 and mature kernel. Each sample has three replicates.