Preliminary Analysis Of Trehalose Biosynthesis Pathway In Quinoa Leaves Under Saline-alkali Stress

Soil salinization and alkalization seriously inhibit crop growth and yields.Increasing the effective cultivated land area through saline-alkali land improvement is conducive to the sustainable development of agriculture.Quinoa（Chenopodium quinoa Willd.）is an annual dicotyledonous plant with high nutritional value of its seeds.Quinoa is highly tolerant to salinization and alkalization,and has unique tolerance mechanism.Exploring the saline-alkali stress resistance genes of quinoa has important significance for molecular breeding of saline-alkali tolerant plants.Trehalose（α-d-glucopyranosyl（1-1）-α-d-glucopyranoside）is a disaccharide,which can serve as signaling molecule,energy source and osmotic protective agent,and plays an important role in plant growth and development and stress response.Trehalose-6-phosphate synthase（TPS）and trehalose-6-phosphate phosphatase（TPP）are key enzymes that catalyze the biosynthesis of trehalose.In order to explore the function of plant Trehalose biosynthesis pathway in response to saline-alkali stress,quinoa seedlings were used as experimental materials,treated with 100 m M Na₂CO₃:Na HCO₃=1:9 alkaline solution,phenotypic observation and related physiological indicators were measured,and bioinformatics analysis was carried out.The main results are as below:1.The TPS and TPP Gene families of quinoa,including 13 TPS and 11 TPP genes,were identified and named CqTPS1-13 and CqTPP1-11,respectively.2.The gene structure,physical and chemical properties,conservative domains and motifs,cis-regulatory elements and evolutionary relationships of TPS gene family proteins in quinoa were analyzed.The results showed that the structural characteristics of TPS and TPP family proteins in quinoa were highly conservative.3.The sequence of 2,000 bp upstream of the start codon was selected as the promoter for cis-regulatory element analysis.The results indicate that CqTPS and CqTPP genes were closely related to light response,plant hormone,plant growth,and stress response,etc.4.The combined analysis of transcriptome and metabolome indicate that the metabolites and genes in the Trehalose biosynthesis pathway significantly changed in quinoa leaves under saline-alkali stress.The metabolites,UDP glucose,D-glucose-1P,D-glucose-6P and D-glucose,were down regulated.The genes related to trehalose biosynthesis,CqTPS4,was significantly up-regulated,while CqTPS3,CqTPS8 and CqTPP4 were significantly down-regulated,This indicates that Trehalose biosynthesis plays an important role in response to saline-alkali stress.In this study,the TPS and TPP Gene family of quinoa were identified,and a preliminary functional analysis were carried out.The saline-alkali stress response genes and metabolites in Trehalose biosynthesis pathway were screened out,which provide basic information for further research.Our findinga provide theoretical basis and gene targets for molecular breeding of saline-alkali tolerant plants.