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Article|01 Mar 2021|OPEN
The genome of Medicago polymorpha provides insights into its edibility and nutritional value as a vegetable and forage legume
Jiawen Cui1,2, Zhaogeng Lu1, Tianyi Wang3, Gang Chen4, Salma Mostafa1, Hailong Ren2, Sian Liu1, Chunxiang Fu5, Li Wang1, Yingfang Zhu6, Jinkai Lu1, Xiang Chen3, Zhenwu Wei2, & Biao Jin1,
1College of Horticulture and Plant Protection, Yangzhou University, 225009 Yangzhou, China
2College of Animal Science and Technology, Yangzhou University, 225009 Yangzhou, China
3Novogene Bioinformatics Institute, 100083 Beijing, China
4College of Bioscience and Biotechnology, Yangzhou University, 225009 Yangzhou, China
5Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, China
6State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, 475001 Kaifeng, China

Horticulture Research 8,
Article number: 47 (2021)
doi: 10.1038/hortres.2021.47
Views: 279

Received: 04 Aug 2020
Revised: 12 Dec 2020
Accepted: 17 Dec 2020
Published online: 01 Mar 2021

Abstract

Medicago polymorpha is a nutritious and palatable forage and vegetable plant that also fixes nitrogen. Here, we reveal the chromosome-scale genome sequence of M. polymorpha using an integrated approach including Illumina, PacBio and Hi-C technologies. We combined PacBio full-length RNA-seq, metabolomic analysis, structural anatomy analysis and related physiological indexes to elucidate the important agronomic traits of M. polymorpha for forage and vegetable usage. The assembled M. polymorpha genome consisted of 457.53 Mb with a long scaffold N50 of 57.72 Mb, and 92.92% (441.83 Mb) of the assembly was assigned to seven pseudochromosomes. Comparative genomic analysis revealed that expansion and contraction of the photosynthesis and lignin biosynthetic gene families, respectively, led to enhancement of nutritious compounds and reduced lignin biosynthesis in M. polymorpha. In addition, we found that several positively selected nitrogen metabolism-related genes were responsible for crude protein biosynthesis. Notably, the metabolomic results revealed that a large number of flavonoids, vitamins, alkaloids, and terpenoids were enriched in M. polymorpha. These results imply that the decreased lignin content but relatively high nutrient content of M. polymorpha enhance its edibility and nutritional value as a forage and vegetable. Our genomic data provide a genetic basis that will accelerate functional genomic and breeding research on M. polymorpha as well as other Medicago and legume plants.