Genetic Reprogramming of Developing Seeds in Low Phytic Acid Soybean.

Seed composition is an economically important trait for crops like soybean, and much research is directed towards improving its nutritional quality. Phytic acid (PA), found in cereal grains and legume seeds cause problems such as indigestion, mineral unavailability, and phosphate pollution. Breeding of low PA (lpa) crops is an eco-friendly alternative to conventional crops. Although lpa crops are desirable, they exhibit altered sugar levels, reduced emergence and low yield, which is a major setback for large-scale cultivation. These low PA (lpa) crops, such as soybean carry mutations that affect PA biosynthesis pathway, during early seed development. For example, point mutations in myo-inositol phosphate synthase (MIPS1) gene, and multidrug-resistance protein (MRP) genes located on chromosomes 19 (MRP-L) and 3 (MRP-N) in soybean are known to cause lpa phenotype. The PA biosynthetic pathway intermediates are also involved in numerous metabolic signaling events. With an objective to identify metabolic reprogramming events of seed development in lpa lines, we hereby compared the global gene-expression profiles of low PA and normal PA developing soybean seeds at 5 developmental stages using transcriptomics approaches. We used two advanced generation recombinant inbred lines (RILs): ABB (low PA due to mips1/mrp-l/mrp-n) and BAA (normal PA due to MIPS1/MRP-L/MRP-N) developed from a single cross. Total 15 mRNA libraries generated from 5 stages of seed development were sequenced from each RIL. We performed differential gene expression analysis and functional gene enrichment analysis to identify differentially expressed genes and differentially represented processes at each developmental stage. Our results represent several genes involved in cellular metabolic and developmental processes. These results are helpful to understand the effect of the lpa mutations on genetic reprogramming of developing seeds.