Molecular ecology and selection in the drought-related Asr gene polymorphisms in wild and cultivated common bean (Phaseolus vulgaris L.)

BMC Genetics

Research Article

Santiago Madriñán¹  Andrés J Cortés²  M Carolina Chavarro³  Matthew W Blair⁴  Dominique This⁵ 

[1] Departamento de Biologia, Universidad de los Andes, Carrera 1 N° 18A – 12, J302, Bogotá, Colombia;Departamento de Biologia, Universidad de los Andes, Carrera 1 N° 18A – 12, J302, Bogotá, Colombia;Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden;Department of Agronomy, University of Georgia, 111 Riverbend Road, Athens, GA, USA;Department of Plant Breeding and Genetics, Cornell University, 242 Emerson Hall, Ithaca, NY, United Sates;Montpellier SupAgro, UMR AGAP, TA-A 108/03, Ave Agropolis, 34398, Montpellier, cedex 5, France;

关键词: Drought Stress;    Gene Pool;    Drought Tolerance;    Nucleotide Diversity;    Common Bean;   

DOI  :  10.1186/1471-2156-13-58

 received in 2012-01-13, accepted in 2012-06-11,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe abscisic acid (ABA) pathway plays an important role in the plants’ reaction to drought stress and ABA-stress response (Asr) genes are important in controlling this process. In this sense, we accessed nucleotide diversity at two candidate genes for drought tolerance (Asr1 and Asr2), involved in an ABA signaling pathway, in the reference collection of cultivated common bean (Phaseolus vulgaris L.) and a core collection of wild common bean accessions.ResultsOur wild population samples covered a range of mesic (semi-arid) to very dry (desert) habitats, while our cultivated samples presented a wide spectrum of drought tolerance. Both genes showed very different patterns of nucleotide variation. Asr1 exhibited very low nucleotide diversity relative to the neutral reference loci that were previously surveyed in these populations. This suggests that strong purifying selection has been acting on this gene. In contrast, Asr2 exhibited higher levels of nucleotide diversity, which is indicative of adaptive selection. These patterns were more notable in wild beans than in cultivated common beans indicting that natural selection has played a role over long time periods compared to farmer selection since domestication.ConclusionsTogether these results suggested the importance of Asr1 in the context of drought tolerance, and constitute the first steps towards an association study between genetic polymorphism of this gene family and variation in drought tolerance traits. Furthermore, one of our major successes was to find that wild common bean is a reservoir of genetic variation and selection signatures at Asr genes, which may be useful for breeding drought tolerance in cultivated common bean.

【 授权许可】

CC BY   
© Cortés et al.; licensee BioMed Central Ltd. 2012