Functional Analysis Of Tomato Aquaporin Gene SlPIP1;5 Under Drought Stress

Tomato(Solanum lycopersicum)is an important economic crop,which needs sufficient water supply for its growth and development.Aquaporin is a functional transmembrane protein widely distributed in various tissues of plants,which can participate in regulating water balance and nutrient elements in plants.Absorption and stomatal movement also play an important role in responding to adversity.Drought is the main factor limiting the growth and development of tomato crops.By breaking the water balance in plant tissues,it affects tomato yield and economic benefits.This paper reveals the function of the tomato aquaporin gene Sl PIP1;5 in tomato response to drought stress.The main results are as follows:1.Combined with the expression of 21 tomato aquaporin genes in roots,stems and leaves and their treatment under drought treatment,Sl PIP1;5,which is highly expressed in tomato leaves and significantly up-regulated under drought conditions,was screened as the target gene and construct S1PIP1:5 overexpression vector,genetically transformed to obtain transgenic positive plants.After drought stress treatment,overexpression of Sl PIP1;5increased the drought tolerance of transgenic plants.2.The content of malondialdehyde(MDA)and hydrogen peroxide(H2O2)in transgenic tomato leaves after drought treatment was significantly lower than that of the control plants;and the reactive oxygen species(ROS)scavenging system superoxide dismutase(SOD)and peroxidase The activities of(POD)and catalase(CAT)were significantly higher than that of the control plants.Under drought stress treatment,the net photosynthetic rate(Pn)of transgenic tomato was significantly increased.The above results further indicate that overexpression of Sl PIP1;5 can increase the activity of antioxidant enzymes and photosynthesis and reduce the degree of damage of tomato plants by drought stress.3.The relative water content(RWC)of the transgenic tomato leaves under drought stress was significantly higher than that of the control tomato,and the leaf dehydration rate was significantly slower than that of the control.Further studies found that the stomatal density of transgenic tomato was smaller,and under drought stress,the stomatal aperture of transgenic tomato was more closed than the control.It indicated that transgenic tomato may reduce the transpiration loss of water by reducing the stomatal density and pore size of the leaves,thereby improving the water retention capacity of transgenic tomatoes.In summary,Sl PIP1;5 overexpressing transgenic tomato under drought stress may reduce the damage degree and water loss rate of tomato by regulating the activity of antioxidant enzymes and stomatal movement in tomato to better maintain the water content of tomato.Balance,which in turn improves the drought resistance of tomatoes.