Dissecting the genetic basis of drought responses in common bean using natural variation

Abstract

The common bean (Phaseolus vulgaris L) is the most important legume for human consumption, contributing 30% of the total daily protein intake in developing countries. A major limitation for its cultivation is drought, which causes more than 60% of the annual losses. Among physiological adaptations to drought, delaying senescence and extending the photosynthetic capacity can improve crop productivity. This strategy is known as functional “stay-green” (SG) and has been discussed as a goal in plant breeding to alleviate the loss of yield under water scarcity conditions. The genetic components behind SG traits have been explored specially in cereals, but they are to date poorly studied in the common bean. For this, we screened 71 common bean cultivars belonging to the three most important gene-pools, Mesoamerica, Andes and Europe, selected to cover the natural variation of the species. Phenotyping experiments under terminal drought during long-days in greenhouse conditions, identified six photoperiod insensitive cultivars of European origin with a clear SG phenotype. Using SNP data produced from whole genome re-sequencing data, we obtained 10 variants significantly associated to the SG phenotype on chromosomes 1, 3, 7, 8, 9 and 10 that are in close proximity to gene models with functional annotations related to hormone signaling and anti-oxidant production. Calculating pairwise FST between subgroups of cultivars divided according to their drought response (susceptibility, escape, recovery or SG), we identified up to 29 genomic windows accounting for 1,45Mb that differentiate SG cultivars; these signals were especially strong on chromosomes 1, 5 and 10. Within these windows, we found genes directly involved in photosynthetic processes and trehalose synthesis. Altogether, these signals represent good targets for further characterization and highlight the multigenic nature of the SG response in legumes.

Enhancing Bean (Phaseolus vulgaris L.) Resilience: Unveiling the Role of Halopriming against Saltwater Stress

“…Since beans are an important crop in the world, it is essential to protect their cultivation and yield, even under salt stress conditions [56,57]. An enhancement in tolerance to salt stress can be achieved by various approaches [23,29,31].…”

Nutritional Characterization of Chilean Landraces of Common Bean

“…Common bean ( Phaseolus vulgaris L.) is one of the most cultivated and consumed legumes in the world, especially in Latin America and Africa [ 1 , 2 ]. Common bean is the most important species among the genus Phaseolus L. cultivated for direct human consumption, contributing about 30% of the total daily protein intake in developing countries [ 3 ]. In addition, the high protein content of common beans is associated with increased satiety, and hence its consumption could help to treat obesity [ 4 ].…”