Abstract Detail

Evolution of Plant Chemical Diversity: Renaissance of comparative biochemistry

Angelovici, Ruthie [1], yobi , Abou  [1], Emery, Marianne [1], Shrestha, Vivek [2], Bagaza , Clement [3], Flint-Garcia, Sherry [4].

The natural variation and regulation of amino acids in maize and Arabidopsis seeds.

Seeds are a major source of protein in human and livestock diets. However, the seeds of major staple crops are deficient in several essential amino acids (EAA). Failure to consume sufficient levels of EAA per day leads to severe malnutrition, even if one’s calorie requirements are met. To improve the amino acid (AA) composition in staple crop seeds, we need a more fundamental understanding of the metabolic and genetic basis that underlies the regulation of both free amino acid (FAA) and protein bound amino acid (PBAA) pools which comprise ~5% and 95% of the total seed AA respectively. Nevertheless, despite the existence of high-throughput quantification (HTQ) method for FAA, there is no such method for PBAA. The latter prevents quantitative genomic enabled analysis of seeds AA levels and composition from large populations and further discovery of their genetic architecture and regulation. To overcome this hurdle, we developed an HTQ method that relies on acid hydrolysis followed by an LC-MS/MS-MRM approach that enables fast, precise and affordable quantification of the absolute levels of 17 PBAA. Utilizing this method, along with FAA HTQ, we have characterized the natural variation of both FAA and PBAA from a 360 ecotype member Arabidopsis association panel as well as a 200 line maize association panel. Our results demonstrated surprising natural variation in both PBAA and FAA. Correlation-based networks constructed from the quantification of both amino acid functional pools revealed no correlation between them in both model systems. Consistently, GWAS analysis of PBAA, FAA and the ratios between them suggests a separate genetic architecture for each. Nevertheless, our results also reveal surprising intersections in their genetic regulation and offer novel insights into the genetic basis of the seed amino acid levels, composition and partition. We posit that this approach can provide novel loci and strategies for future seed amino acid biofortification.

1 - University of Missouri , Division of Biological Science , 1201 Rollins St, Columbia, MO 65201, Columbia, MO 65201, MO, 65211-0001, United States
2 - University of Missouri , Division of Biological Science , 1201 Rollins st, Columbia, MO, 65211-0001, United States
3 - University of Missouri , Division of Biological Science , 1201 Rollins st, Columbia, MO, 56211
4 - University of Missouri , USDA, 301 Curtis Hall, Columbia,, MO, 65211, United States

Keywords:
amino acids 
natural variation.

Presentation Type: Symposium Presentation
Session: SY5, Evolution of Plant Chemical Diversity: Renaissance of comparative biochemistry
Location: 102/Mayo Civic Center
Date: Wednesday, July 25th, 2018
Time: 10:15 AM
Number: SY5006
Abstract ID:1045
Candidate for Awards:None