Plant responses to drought, acclimation, and stress tolerance

At the whole plant level, the effect of stress is usually perceived as a de crease in photosynthesis and growth. That is why this review is focused mai nly on the effect of drought on photosynthesis, its injury, and mechanisms of adaptation. The analysed literature shows that plants have evolved a num ber of adaptive mechanisms that allow the photochemical and biochemical sys tems to cope with negative changes in environment, including increased wate r deficit. In addition, the acquisition of tolerance to drought includes bo th phenotypic and genotypic changes. The approaches were made to identify t hose metabolic steps that are most sensitive to drought. Some studies also examined the mechanisms controlling gene expression and putative regulatory pathways.