Effect of Flooding on Physiology and Expression of Aquapurin 1 (PIP1) Gene in Pepper

Flooding stress causes a lack of oxygen and impaired root activity, part of which is related to the possible effects of aquaporins.The factorial experiment was performed in a CRD design with treatments including the flooded plants with active aquaporin and the flooded plant with active aquaporin at two or 10 days after stress. With the loss of aquaporin activity, the fresh and dry weight of the shoots and roots decreased and the duration of the stress did not affect it. The potential of leaf and root water in aquaporin’s-free flood stress was more negative than in flood and control, and the potential of root water under long-term flood stress was more negative than the short-term stress. The content of abscisic acid in flood stress increased so that in the presence of aquaporin for a long time it increased the abscisic acid and in the absence of aquaporin increased in a short time. Expression of the root and leaf aquaporin gene increased in flooding stress and the absence of aquaporin in the long term decreased in the short term. In general, the antioxidant index was more affected by the duration of stress. The amount of potassium and abscisic acid in the plant increased in the absence of aquaporin to maintain the water content of the plant by closing the stomata. On the other hand, carotenoids as a precursor to the production of abscisic acid increased. In general, the presence of root aquapurins seems to play an important role in maintaining water balance in pepper in flooded conditions.