Expression Dynamics of Gene and Accumulation Pattern of Phytate in Maize Genotypes Possessing and Genes at Different Stages of Kernel Development.

Phytic acid (PA) acts as a storehouse for the majority of the mineral phosphorous (P) in maize; ~80% of the total P stored as phytate P is not available to monogastric animals and thereby causes eutrophication. In addition, phytic acid chelates positively charged minerals making them unavailable in the diet. The mutant allele reduces PA more than the wild-type allele. Further, mutant gene () enhances lysine and tryptophan and enhances provitamin-A (proA) more than wild-type and alleles, respectively. So far, the expression pattern of the mutant allele has not been analysed in maize genotypes rich in lysine, tryptophan and proA. Here, we analysed the expression pattern of wild and mutant alleles of , and genes in inbreds with (i) mutant -, and alleles, (ii) wild-type allele and mutant and alleles and (iii) wild-type , and alleles at 15, 30 and 45 days after pollination (DAP). The average reduction of PA/total phosphorous (TP) in mutant inbreds was 29.30% over wild-type allele. The and -based inbreds possessed ~two-fold higher amounts of lysine and tryptophan, and four-fold higher amounts of proA compared to wild-type alleles. The transcript levels of , and genes in -based inbreds were significantly lower than their wild-type versions across kernel development. The , and genes reached their highest peak at 15 DAP. The correlation of transcript levels of was positive for PA/TP (r = 0.980), whereas it was negative with inorganic phosphorous (iP) (r = -0.950). The and transcripts showed negative correlations with lysine (r = -0.887) and tryptophan (r = -0.893), and proA (r = -0.940), respectively. This is the first comprehensive study on expression in the maize inbreds during different kernel development stages. The information generated here offers great potential for comprehending the dynamics of phytic acid regulation in maize.