Location: Vegetable ResearchTitle: Genome-wide association study and population structure analysis of seed-bound amino acids and total protein in watermelon
|JOSHI, VIJAY - Texas A&M University|
|NIMMAKAYALA, PADMA - West Virginia State University|
|SONG, QIUSHUO - West Virginia State University|
|LAKSHMI, VENKATA - West Virginia State University|
|NATARAJAN, PURUSHOTHAMAN - West Virginia State University|
|CROSBY, KEVIN - Texas A&M University|
|REDDY, UMESH - West Virginia State University|
Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2021
Publication Date: 10/19/2021
Citation: Joshi, V., Nimmakayala, P., Song, Q., Lakshmi, V.A., Natarajan, P., Levi, A., Crosby, K., Reddy, U. 2021. Genome-wide association study and population structure analysis of seed-bound amino acids and total protein in watermelon. Plant Science. https://doi.org/10.7717/peerj.12343.
Interpretive Summary: Watermelon is cultivated throughout the world for its sweet dessert flesh. However, watermelon have been also cultivated for seed consumption. Watermelon seeds are rich with proteins, amino acids, vitamins, and essential minerals and have been considered an important food source in most parts of the world. There is no sufficient information on the natural genetic variation and on the genes that control production of amino acids and proteins in watermelon seeds. In this study, ARS scientists have collaborated with scientists in West Virginia State University and in Texas A&M on evaluating watermelon genetic material to identify the genes involved in amino acids and protein production in watermelon seeds. The scientists identify 180 candidate genes that could be associated with amino acid and protein production in seeds. The results in this study provide a robust platform for further studies, and for plant geneticists and breeders aiming to develop watermelon varieties with highly nutritional seeds, rich in amino acids and proteins suitable for human consumption.
Technical Abstract: Watermelon seeds are a powerhouse of proteins, free amino acids, vitamins, and essential minerals, offering a paleo-friendly dietary option. Despite substantial genetic variation, there is no sufficient information of natural variation in seed-bound amino acids or proteins across watermelon germplasm. This study aimed to analyze the natural variation in watermelon seed amino acids and total protein and explore underpinning genetic loci. Seed-bound free amino acids and total protein were evaluated in 211 watermelon accessions, including 165 Citrullus lanatus, and 54 Citrullus mucosospermus (egusi), and 2 Citrullus amarus. We used by genome-wide association study (GWAS) based on 11,456 single nucleotide polymorphisms (SNPs) to associate seed phenotype. The GWAS analysis identified 228 SNPs coinciding with 180 candidate genes associated with watermelon seed-bound amino acids and total protein. The candidate genes involved in amino acid metabolism which validate their functional relevance and potential for marker-assisted selection. This study provides a platform of potential gene loci involved in seed-bound amino acid metabolism.