Impact of drought stress on physiological characteristics and isolation of chloroplasts in common bean (Phaseolus vulgaris L.)

Chloroplasts are involved in many cellular processes and play an important role in plant stress response. In this study, the effect of drought on different physiological characteristics and the isolation of chloroplasts from leaves of drought-stressed and control plants of common bean (Phaseolus vulgaris L.) are reported. Two cultivars differing in the response to drought were analysed-Tiber and more sensitive Starozagorski eern. The results of relative water content showed that plants were under mild stress conditions after six days without watering. Negative effects of drought stress on the photosynthetic rate and chlorophyll fluorescence parameters of both cultivars were observed. The yield of isolated chloroplasts in control samples of both cultivars was at least three times higher compared to drought-stressed samples. The intactness of the isolated chloroplasts was checked and used for protein isolation. The results of the study suggested that even mild drought stress strongly affected the isolation of intact chloroplasts. Still, intact chloroplasts were enriched and were suitable for downstream proteomic analysis.