Adzuki bean (Vigna angularis) is well known as a non-oil legume crop that has been grown in more than 30 countries of the world. The seeds of Adzuki bean, compared to soybean, has much more starch (57.06% vs. 25.3%) and much less crude fat (0.59% vs. 22.5%), which is used as an important source of starch, digestible protein, mineral elements and vitamins for at least a billion people.
To accelerate the application of adzuki bean genome and better understand of the underlying biology mechanism of its distinct characters, a collaborated team led by Dr. WAN Ping from Beijing University of Agriculture, Drs. LING Hongqing and TIAN Zhixi from Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, and BGI-Shenzhen successfully generated a high quality draft genome of adzuki bean, in which 86.11% (466.7 Mb of 542 Mb) genome with scaffold N50 size of 1.29 Mb was assembled.
In addition to analyzing typical genome features, e.g. repetitive DNA, gene prediction, gene family analysis, they also revealed that adzuki bean is more conserved with common bean by comparison analysis with 6 sequenced legume genomes. More important, through comparative genomic and transcriptome analyses, they demonstrated that the significant difference in starch and fat content between adzuki bean and soybean is caused by the transcriptional abundance, rather than copy number variations, of the genes related to starch and oil synthesis.
Furthermore, re-sequencing of 49 accessions including 11 wild, 11 semi-wild, 17 landraces, and 10 improved varieties and population analyses provided strong selection signals in domestication and revealed that semi-wild adzuki bean is the progenitor species of cultivated adzuki bean.
The genome sequence of adzuki bean will facilitate the identification of agronomically important genes and accelerate the improvement of adzuki bean.
This research was supported by grants from Research Base and Technological Innovation Platform Project of Beijing Municipal Education Committee, Enhancing Scientific Research Level of the Beijing University of Agriculture, and National Natural Science Foundation of China.
