Differential anatomical and physiological responses to short-termed water deficit on pedicel of two common bean (Phaseolus vulgaris L.) genotypes with different growing cycle

Water deficit is a major constraint to common bean ( Phaseolus vulgaris L.) production, limiting water and photoassimilate transport through the peduncle–pedicel–pod complex to developing seeds. This study examined anatomical and functional responses of the pedicel during pod filling in two genotypes with contrasting growth cycles: OTI (intermediate cycle, ~120 days) and Rosa Bufa (RB; short cycle, ~70 days). Plants were subjected to short-term water deficit (50% field capacity) for 10 days, followed by a 10-day rehydration period. OTI pedicels exhibited stronger recovery of water status, reflected by higher relative water content after rehydration, whereas RB showed limited recovery. Anatomical analyses revealed that OTI displayed pith expansion and vascular adjustments under water deficit, indicating greater structural plasticity that may enhance water and nutrient transport to developing pods. In contrast, RB exhibited greater cortical collapse and restricted anatomical responsiveness. Pod fresh mass increased significantly after rehydration in both genotypes, suggesting compensatory post-stress growth, while pedicel biomass remained relatively stable. These findings identify the pedicel as a dynamic and responsive organ during transient drought and highlight genotype-dependent anatomical plasticity as a potential contributor to reproductive resilience under water-limited conditions. • Pedicel anatomy shows drought-induced plasticity in common bean • OTI genotype exhibits stronger water status recovery than RB • Pith and vascular traits contribute to drought resilience • Pedicel adjustments support pod hydration under water deficit