BIO-BELIEF project: Drought tolerance in nutritionally-optimized common beans

Common beans (Phaseolus vulgaris L.), a staple food in many regions of the world, are a major source of dietary fibers, essential amino acid-rich proteins, some vitamins and often display a high content in essential minerals such as iron, zinc and calcium. However, these minerals are scarcely bioavailable, mainly due to the presence of phytic acid (PA) and phenolic compounds. Besides, about 60% of common beans produced worldwide are grown in regions subjected to water stress, the second most important factor that contributes to yield reduction. To address this problem, BIO-BELIEF, a multidisciplinary project consisting of a trans-continentalconsortium of European (CREA-GB and CNR-IBBA in Italy and INRAE, INSERM in France); and African partners (CIAT in Kenya and the University of Pretoria with UKZN andStellenbosch University as local South African partners) with Embrapa in Brazil and the seedcompany Blumen in Italy as partners in kind, aims to select new biofortified more droughtresilient common bean lines, in order to promote a healthy diet in a general frame of food andnutrient security. The approach, to study biofortified common beans lines exposed to drought,has, to our knowledge, never been done before and is therefore innovative. Current researchactivities and results already obtained include that 20 common bean lines derived from Europeand Africa have been already planted for seed multiplication and the germination potential ofdifferent lines, including lpa mutant lines low in phytic acid, is currently tested in twocontinents (Europe and Africa at three test sites). First results already indicate that a low phyticacid content does not significantly affect seed germination. Common bean lines are currentlyalso tested in the field and greenhouse for drought tolerance in Italy (open field and greenhouse)and in South Africa (open field under rainout shelters) by applying the leaf wilting techniquefor monitoring drought tolerance. Selected lines will be further used for introgression of thebiofortification trait into a drought-resilient genetic background and the innovative technologyof Genome Editing (GE) will also be applied in a next step to modify/silence candidate genesinvolved in phytic acid production and drought tolerance. In particular, PvMYB 60, atranscriptional repressor of anthocyanin, and PvDREB 2, a transcription factor coding for adehydration-responsive element binding protein, which are both described as negativeregulators of the drought stress response will be selected to be edited in order to develop moredrought-tolerant common bean lines. Biofortified lines will be further exploited in the next twoyears by preparing bean-based recipes, which will be characterized for their nutritional profileand micronutrient bioavailability. All identified superior lines will be finally tested byconsumers to validate any new biofortified diets for European, African and South Americanpopulations. Overall, we expect that the project will ultimately release breeding lines, with ahigh nutritional value and more drought-resilient, suitable to be grown in Europe, Africa andLatin America. For more information including a video on the BIO-BELIEF project see forexample https://www linkedin com/company/biobelief/ as well as in the two recentpublications Losa et al. (2022). Drought and heat affect common bean minerals and humandiet--What we know and where to go. Food and Energy Security 11:e351. doi:10.1002/fes3.351 and Cominelli et al. (2022). Antinutritional factors, nutritional improvement,and future food use of common beans: A perspective. Frontiers Plant Sciences 13:992169. doi:10.3389/fpls.2022.992169