| With the people’s living standards improve,the problem of soil salinization is becoming more and more prominent,which seriously restricts the growth and development of green plants and affects their yield and quality.Sweet cherry(Prunus avium),as an economic tree species widely cultivated in the world,is extremely sensitive to salt stress.Therefore,it is of great significance to improve the salt tolerance of sweet cherry rootstocks for the development of sweet cherry industry.Lectin-like receptor protein kinases(Lec RLKs)belong to the second largest subfamily of receptor-like protein kinases(RLKs),which can regulate plants development and induce plants innate immune responses when plants perceive external stress signals,and play a crucial role in improving plant stress tolerance.At present,related studies mainly focus on the selection and breeding of new sweet cherry rootstock varieties,and the molecular mechanism of Lec RLKs in sweet cherry rootstocks in response to salinity stress is still unclear.Therefore,it is important to investigate the molecular mechanism involved in regulating the response of Lec RLKs to salt stress for breeding sweet cherry rootstocks with excellent salinity resistance traits.In this study,161 sweet cherry Lec RLKs were identified by bioinformatics.The transcriptome was used to analyze the expression levels of Lec RLKs under different stresses,and it was found that these genes showed strong response to salt stress,and PaLectinL16 showed the most obvious response to salt stress.The characteristics and subcellular localization of PaLectinL16 were further analyzed,and it was found that PaLectinL16 is a membrane receptor protein.Finally,functional verification was conducted.The overexpression vector was constructed,and the sweet cherry rootstock‘Gisela 6’ was transformed by agrobacterium-mediated method to obtain transgenic plants.The positive transgenic plants were screened and identified,and the phenotype,physiological and biochemical indexes of transgenic cherry seedlings were analyzed and measured,so as to verify the function of PaLectinL16 in response to salt stress.This study provides a comprehensive analysis of PaLecRLKs in the sweet cherry rootstock ‘Gisela6’,elucidating their potential great role in the resistance to external environmental stresses.The main findings were as follows:(1)Bioinformatics analysis of PaLecRLKs family.We identified 161 PaLecRLKs genes in the genome of sweet cherry.Phylogenetic analysis revealed that PaLecRLKs could be classified into three types: L type(50),G type(110)and C type(1).The phylogenetic tree analysis has divided PaLecRLKs into five isoforms(I-V).Among them,PaLectinL16 was classified in the second isoform,which is more closely related to At5G10530 and At5G65600 in Arabidopsis,and presumably they may have similar protein functions.(2)Expression profiling of the PaLecRLKs gene family showed that the expression of different genes differed significantly under different stress conditions.Among them,most L-type PaLecRLKs genes were highly expressed under both biotic and abiotic stresses,especially in response to Na Cl stress.We also found that some L-type PaLecRLKs genes would be induced to be highly expressed under more than two stress treatments.This suggests that these genes may initiate the same response mechanism in response to different stress signals.(3)The overexpression vector of PaLectinL16 was constructed,and the sweet cherry rootstock ‘Gisela 6’ was transformed by agrobacterium-mediated method.After further screening and identification,transgenic positive plants were obtained.It was found that overexpression of PaLectinL16 in ‘Gisela 6’ could enhance its resistance to salt stress.In addition,the overexpression of PaLectinL16 also improved the salt tolerance of ‘Gisela 6’ by increasing the activity of reactive oxygen scavenging enzymes and upregulating related genes. |
PDF Full Text Request