IDENTIFICATION OF GENES THAT REGULATE SOYBEAN OIL CONTENT: GENOME-WIDE TRANSCRIPT ANALYSIS OF SOYBEAN NEAR-ISOGENIC LINES
Plant Science Research
2012 Annual Report
1a.Objectives (from AD-416):
The objective of the research is to characterize two of the genes identified as differentially expressed as candidates for genes involved in regulation of soybean oil content. The long-term goal is to facilitate targeting of regulatory genes that will enhance seed oil content in U.S. soybeans.
1b.Approach (from AD-416):
1. Determine the location of candidate gene expression and action. Prepare two constructs for in situ hybridization and evaluate 30 sections of seed for transcript localization.
2. Create transgenic soybeans for evaluation of candidate gene function. Prepare two RNAi constructs containing the two candidate genes under the control of seed-specific promoters and transform two RNAi constructs into soy to generate T1 soybean seed for evaluation.
3. Evaluate transgenic plants that over-express multidrug toxin efflux (MATE) and malate dehydrogenase (MDH) genes for yield and seed quality.
4. Annotate transcripts encoding transporters, steps in carbon and nitrogen metabolism, signal transduction components, and hormone biosynthesis specific to each of 12 tissues from both NILS lines.
5. Characterize gene sub-functionalization within selected soybean gene families.
This research addresses Objective 3 of the parent project 3640-21000-028-00D: Determine genes regulating oil and protein accumulation in soybean through whole genome transcript analysis and functionally characterize gene candidates.
Utilizing soybean recombinant inbred lines (RILs) that differ in oil and protein, we did whole genome RNA transcript analysis during seed development. Quantitative trait loci (QTLs) based on seed gene expression were identified. One of the main QTLs was located on chromosome 7 involving the chalcone synthase gene. Another QTL was on chromosome 20 and involved oleosin genes. These data show that seed oil, protein, and flavonoids are interrelated. The results indicate that oil and protein quality in soybean are controlled by many QTLs with small effects.