Development of a biotech toolbox for bean research

Research on common bean genetics and molecular biology faces challenges due to its complex genome, high genetic diversity (within and between Mesoamerican and Andean gene pools), and phenotypic plasticity. Hindered by limited forward genetic methods, the use of low-efficiency protocols (biolistic transformation) and recalcitrance to in vitro regeneration, identifying key genes and traits remains difficult. Among the tools developed for this purpose we count two EMS-mutagenized populations for an approach of TILLING (Targeting Induced Local Lesions In Genomes); we have so far exploited this in the study of the domestication of common bean, using a previously described population in the BAT93 genotype. Moreover, a newly developed population in the MECCEARLY genotype will be used to identify genes involved in the accumulation of nutritional compounds (starch, phosphate, minerals) and antinutritional/bioactive ones (phytic acid, raffinosaccharides, trypsin inhibitor). In parallel with these mutagenesis-based methods, we are working on the improvement of in vitro protocols and the development of next-generation vectors based on those already tested in other species with low regenerative potential (such as wheat), which would increase the efficiency of transformation and regeneration of bean embryonic axes after biolistics. Altogether, these efforts could be crucial in the frame of global food security, for enhancing crop productivity, genetic diversity and nutritional quality.