The Expression Analysis Of Terpenoids Synthesis And Aquaporins Genes And Research Of Physiological And Biochemical Features In Maize Under Salt Stress Conditions

Soil salinization is a kind of abiotic stress that affects the growth of plant and crop yield seriously.Maize is one of the main food crops in the world.Thus it is an important way that cultivating the new maize varieties of high quality,high yield and salt tolerance to solve the problem of food and environment.The study analyzed the difference of salt resistance and genes expression among Tianta 5 and its parent lines?825 and HOO-108?to explore salt tolerance and heterosis mechanism of maize.The research aimed at providing theoretical basis for molecular breeding of stress-tolerance plant.The Tianta 5 and its parent lines were treated with 0,100,200,400 mmol·L^-1 NaCl when they were at germination stage and three-leaf stage.The indicators of germination potential and germination index of seed,plant height,biomass and relative water content,etc,were compared to analyze the salt tolerance of Tianta 5 and its parent lines.The contents of MDA,chlorophyll,free proline,soluble protein and carotenoids and photosynthetic rate were detected further of Tianta 5 and its parent lines treated with 200 mmol·L^-1 NaCl.The results showed that the salt resistance of Tianta 5 was significantly higher than the parent lines,and Tianta 5 could reduce damage to plants caused by salt stress by the accumulation of osmotic regulation substances and antioxidants.The 130 differentially expressed genes in maize transcriptome under the condition of salt stress were analyzed.According the results,sets of genes were selected to detect with qRT-PCR,which expressed differently significantly in Tianta 5 compared with the parent lines,including terpenoids synthesis genes,such as prenyl transferase,geranylgeranyl diphosphate synthase 4?GGPS4?,terpene synthase 2?TPS2?,terpene synthase 3?TPS3?,and aquaporins genes,such as PIP2-4,PIP1-6,NIP2-1,NIP1-1,TIP1-2,SIP2-1.The results showed that the expression level of terpenoids synthesis related genes increased then decreased in maize under salt stress,and the expression level in Tianta 5 was much higher than its parent lines.Also,the difference of expression level of aquaporins was confirmed in Tianta 5,compared with its parent lines.In conclusion,terpenoids synthesis genes and aquaporins genes were involved in the response to salt stress in maize,and help to enhance the ability of resistting stress of hybrid Tianta 5.