Genes involved in cross-tolerance to drought and salinity in Leymus:Identification and expression analysis in wheat-Leymus chromosome addition lines

摘要

Leymus mollis(Triticeae; Poaceae)is a useful genetic resource for wheat breeding via wide hybridization to introduce its chromosomes and integrate its useful traits into wheat.Although L.mollis is highly tolerant to drought and salinity,and resistant to various diseases,the genetic mechanisms controlling its physiological tolerance remain largely unexplored.We have differentially screened Leymus cDNA libraries and identified several genes found to be involved in cross-response and cross-tolerance to drought and salinity.Some of these genes were found to be upregulated not only under drought and salt stresses,but also under temperature-induced stresses and in response to plant phytohormones.Genes involved in the synthesis of jasmonic acid,an important stress signaling compound,were identified,including those for lipoxygenase and allene oxide cyclase(AOC).We also identified genes involved in the biosynthesis and metabolism of glycine betaine,a solute which protects cells from dehydration injury,such as those for phosphoethanolamine methyltransferase(PEAMT)and glycine decarboxylase.