| Inositol 1,2,3,4,5,6-hexakisphosphate, phytic acid, is the most abundant phosphorus-containing molecule in seeds of plants. Low phytic acid (lpa) crop genotypes have been developed with reduced levels of seed phytate. Research on the accumulation of phosphorus in seeds during development as well as changes in gene expression of lpa genotypes is very limited. These studies investigate the accumulation of phosphate and phosphorus-containing molecules during seed development of four different barley lpa genotypes. Changes in phytic acid P and inorganic P are evident early in seed development, in all the lpa genotypes as compared to the wild-type line Harrington. Total P accumulation is similar throughout development for the lpa genotypes and Harrington. Differences between years are evident in seed weight, phytic acid P, and non-phytate P. Experiments are also performed on the changes in gene expression early in development of M955, a low phytic acid genotype with over 90% reduction in seed phytate. Expression of genes involved in sugar synthesis, transport, and starch deposition are reduced in M955. At this time point, no change is evident in genes related to inositol and phytic acid metabolism. This indicates that the mutation in M955 may not have initial impacts on expression of genes related to phytic acid synthesis, but may have impacts on sugar metabolism and transport. |
