Identification And Functional Analysis Of Members Of Camellia Sinensis (L.) ABA Signal Transduction Family

ABA is a natural and key hormone synthesized by plants.It is widely present in various tissues and organs of higher plants and is involved in regulating various aspects of plant growth and development,including: seed dormancy,seedling growth,leaf senescence,etc.At the same time,ABA is also an anti-stress hormone that responds to various stresses,such as drought,salt,and low temperature.As one of the important horticultural crops in China,tea tree is a perennial plant that loves temperature,humidity and humidity,and has weak drought tolerance.Drought and lack of water have a serious impact on the normal growth of tea trees and tea yield and quality.And with the bad conditions of the world’s climate,this problem has become more serious.Therefore,the cultivation of drought-tolerant tea varieties is one of the most important measures to deal with drought stress.However,the research on tea tree stress resistance mechanism is still in the preliminary stage,and the knowledge and understanding of tea tree stress resistance related genes is still little.This paper analyzes the tissue distribution of the tea tree ABA signal transduction system PYL,PP2 CA,Sn RK2 gene family,the expression pattern in stress,and the interaction between them to analyze the tea tree ABA signal transduction pathway,which is a The research provides molecular basis and provides a basis for finding drought-resistant varieties,which has important theoretical and practical significance.Based on the tea tree genome database TPIA,this paper has identified members of the ABA receptor and signal transduction family,PYR / PYL / RCAR1 gene family,PP2 CA gene family,and Sn RK2 gene family in tea plants.Among them,three CsPYL genes(CsPYL11-13)There is a deletion,which is considered a pseudogene.The basic structure of CsPYLs / CsPP2 CAs / CsSn RK2 s gene families and their expression patterns under different tissues and various abiotic stresses(drought,salt,low temperature)were analyzed;q RT-PCR was used to detect the expression changes of CsPYLs / CsPP2 CAs / CsSn RK2 s gene families of different tea varieties under drought treatment.The effects of exogenous ABA treatment on CsPYLs / CsPP2 CAs /CsSn RK2 s in tea seedlings were analyzed and according to this result,a tea tree ABA signal transduction route map was established,and some genes were cloned.Using yeast two-hybrid technique to detect the interaction of CsPYLs / CsPP2 CAs /CsSn RK2 s family proteins,the transduction process of ABA signal in tea plants was preliminarily explored.The main findings are as follows:1)Using the TPIA,15 CsPYLs genes,8 CsPP2 CAs genes,and 8 CsSn RK2 s genes were identified,named CsPYL 1-15,CsPP2CA1-8,CsSn RK2.1-8.According to the analysis of gene structure and phylogenetic tree,CsPYLs are divided into 3 groups,CsPP2 CAs are divided into 2 groups,and CsSn RK2 s are divided into 3 groups.The three families are expressed in different organizations and show differences.In the CsPYLs family,CsPYL4 is highly expressed in mature leaves and rhizomes,CsPYL5 is highly expressed in young leaves and flowers,and CsPYL9 is highly expressed in seeds;the expression levels of CsPYL1-2 and CsPYL14-15 are low in all tissues.In the CsPP2 CAs family,CsPP2CA3 has a higher expression level in the root,CsPP2CA8 has a higher expression level in the aerial parts,and CsPP2CA4 has a higher expression level in all tissues.In the CsSn RK2 s family,CsSn RK2.3 is highly expressed in all tissues,and CsSn RK2.8 is highly expressed in leaves.2)The three families of CsPYLs / PP2 CAs / Sn RK2 s have diverse responses to drought,salt and low temperature stress.Under drought stress,the gene expression of the CsPYLs family showed different response patterns,of which CsPYL10,15 showed significantly up-regulated expression,and CsPYL14 significantly down-regulated expression;the CsPP2 CA family as a whole is up-regulated,of which the CsPP2CA1 response is the strongest;the CsSn RK2 family is mostly down-regulated.Under salt stress,the three families showed different response patterns,CsPYL1,4-5,15 showed significantly up-regulated expression,CsPYL3,14 significantly down-regulated expression;in the CsPP2 CA family,only CsPP2CA6 showed significant down-regulated expression,other family members were not significant;CsSn RK2.5,6,8 showed down-regulated expression.Under low temperature stress,CsPYL1 showed significant up-regulated expression,CsPYL4,5 showed down-regulated expression;CsPP2CA5,6 showed up-regulated expression;CsSn RK2 s family was not significant.3)Under drought treatment,the gene expression of CsPYLs / PP2 CAs / Sn RK2 s gene of different varieties of tea trees showed different response patterns.Among them,the drought-sensitive variety "Ruanzhiwulong",the response of the three families of CsPYLs / PP2 CAs / Sn RK2 s was significantly higher than that of the drought-tolerant variety "Zhongcha 108".It shows that the molecular mechanisms of drought tolerance of different tea varieties are different.4)Under the treatment of exogenous ABA,the expression of CsPYLs / CsPP2 CAs /CsSn RK2 s is different,and the expression of different tissue parts also shows different expression patterns.Correlation analysis was performed on the expression levels of the two tissues and organs of roots and leaves in ABA treatment at 0 h,0.5 h,2 h,6 h,and 24 h.According to the results of correlation analysis,three ABA-dependent signal transduction pathways of tea trees were drawn.CsPYL4 / CsPYL7 / CsPYL9 /CsPYL15-CsPP2CA2-CsSn RK2.8,CsPYL2 / CsPYL3-CsPP2CA1-CsSn RK2.7 /CsSn RK2.1 and CsPYL6 / CsPYL14-CsPP2CA8-CsSn RK2.6.5)CsPYL4 / CsPYL7 / CsPYL9 / CsPYL15-CsPP2CA2-CsSn RK2.8 signal transmission route of CsPYL4 / CsPYL7,CsPP2CA8,CsSn RK2.6 and CsPYL6 were constructed into yeast two-hybrid bait vector p GADT7 and capture vector p GBKT7 and co-transformed yeast Y2 H Gold strain.The results of yeast two-hybrid proved that the drawn ABA-dependent signal transduction pathway of tea tree is of reference.In summary,the identification of the three gene families of CsPYLs / PP2 CAs /Sn RK2 s and the analysis of their biological functions have laid a certain foundation for the investigation of ABA signaling molecules in tea trees;Analysis of the regulation mechanism of ABA signal transduction families of different tea tree varieties under drought treatment provides new ideas for the study of tea tree drought resistance and is helpful to further clarify the tea tree drought resistance mechanism.