title: Natural variation and gene regulatory basis for the responses of asparagus beans to soil drought.
abstract: Asparagus bean (Vigna unguiculata ssp. sesquipedalis) is the Asian subspecies of cowpea, a drought-resistant legume crop native to Africa. In order to explore the genetic variation of drought responses in asparagus bean, we conducted multi-year phenotyping of drought resistance traits across the Chinese asparagus bean mini-core. The phenotypic distribution indicated that the ssp. sesquipedalis subgene pool has maintained high natural variation in drought responses despite known domestic bottleneck. Thirty-nine SNP loci were found to show an association with drought resistance via a genome-wide association study (GWAS). Whole-plant water relations were compared among four genotypes by lysimetric assay. Apparent genotypic differences in transpiration patterns and the critical soil water threshold in relation to dehydration avoidance were observed, indicating a delicate adaptive mechanism for each genotype to its own climate. Microarray gene expression analyses revealed that known drought resistance pathways such as the ABA and phosphate lipid signaling pathways are conserved between different genotypes, while differential regulation of certain aquaporin genes and hormonal genes may be important for the genotypic differences. Our results suggest that divergent sensitivity to soil water content is an important mechanism configuring the genotypic specific responses to water deficit. The SNP markers identified provide useful resources for marker-assisted breeding.
authors.affiliation: Institute of Vegetables, Zhejiang Academy of Agricultural Sciences Hangzhou, China ; State Key Lab Breeding Base for Sustainable Control of Plant Pest and Disease, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Xu
authors.affiliation: The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Menachem
authors.initials: M
authors.lastname: Moshelion
authors.affiliation: Institute of Vegetables, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: XiaoHua
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Soil and Water Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Ofer
authors.initials: O
authors.lastname: Halperin
authors.affiliation: Institute of Vegetables, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: BaoGen
authors.initials: B
authors.lastname: Wang
authors.affiliation: Institute of Digital Agriculture, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Soil and Water Sciences, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem Rehovot, Israel.
authors.forename: Rony
authors.initials: R
authors.lastname: Wallach
authors.affiliation: Institute of Vegetables, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Wu
authors.affiliation: Institute of Vegetables, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Zhongfu
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Institute of Vegetables, Zhejiang Academy of Agricultural Sciences Hangzhou, China ; State Key Lab Breeding Base for Sustainable Control of Plant Pest and Disease, Zhejiang Academy of Agricultural Sciences Hangzhou, China.
authors.forename: Guojing
authors.initials: G
authors.lastname: Li
keywords: GWAS; asparagus bean (Vigna unguiculata ssp. sesquipedalis); cowpea; drought; microarray; natural variation; water relations