Identification And Functional Analysis Of StMADS11 Subfamily Genes In Hickory(carya Cathayensis Sarg.)

Hickory(Carya cathayensis Sarg.)is a famous characteristic economic dry fruit and woody oil tree.It is a perennial woody plant with a long juvenile phase,taking about 10 years from seedling of hickory seeds to bearing fruit.When the tree enters the reproductive stage,there are temporal and spatial differences in the formation of female and male flowers,different placement sites,different differentiation times,and different quantities,which seriously affects the hickory yield and hinders quality improvement.Studies have shown that the StMADS11 subfamily plays an important role in the regulation of flowering period,flower development and the maintenance of flower bud dormancy.And there are functional differences among the StMADS11 subfamily genes in annual herbs and perennial woody plants.This paper further elucidates the regulatory role of StMADS11 subfamily in hickory flower development through phylogenetic analysis,gene expression,subcellular localization,transgene validation,protein interaction and transcriptional regulation.The main results are as follows.(1)The bioinformatics analysis were investigated.The results showed that: a total of five StMADS11 subfamily genes were identified in the hickory genome,which could be divided into three evolutionary branches: AGL24,SVP,and JOINTLESS.According to the clustering characteristics,Cc SVP-like,Cc AGL24-like1,Cc AGL24-like2,Cc JOINTLESS-like1 and Cc JOINTLESS-like2 had their own uniqueness in intron length,C domain,conserved motifs and binding elements,which may be the reason for the functional differentiation of these five genes.(2)The expression patterns and subcellular localization were investigated.The results showed that the expression level of StMADS11 subfamily genes was the highest in the female flower buds of hickory pecan,and the expression pattern in the female flower buds was seasonally changed.The expression levels of two genes in the same subclade showed one high and one low.Furthermore,only Cc JOINTLESSlike1/2 localized exclusively in the nucleus,consistent with their function as transcription factors.(3)By observing the transgenic Arabidopsis,the results showed that the overexpression of the StMADS11 subfamily gene in Arabidopsis influenced the flower organs and fruit pods of Arabidopsis.Cc SVP-like overexpression lines had the most prominent effect on floral organs.The sepals were severely leafed and covered with hairs,the petals were green,the pods were shorter and covered with hairs,and the flowering time was delayed.Cc AGL24-like1/2 overexpressing lines,the pods were hairless and wrinkled,Cc AGL24-like1/2 overexpressing lines,the pods were hairless and wrinkled,which were early flowering.The inflorescence of Cc JOINTLESS-like1/2 overexpression line were similar to wild type,while the fruit pod folds were significantly wrinkled and slender,and the flowering time was earlier.(4)The protein interaction and transcriptional regulation were studied,the results showed that Cc SVP-like,Cc AGL24-like1/2,Cc JOINTLESS-like1/2 proteins can interact with Cc FUL-like proteins in vitro and in vivo.Howerer,only Cc FUL-like,Cc SVP-like,Cc JOINTLESS-like1/2 proteins could bind to the Cc SOC1-like promoter and inhibit the expression of Cc SOC1-like.In summary,this study identified five StMADS11 subfamily genes in the hickory genome,all of which are involved in the development of floral organs during flowering.Among them,Cc SVP-like may inhibit hickory flower formation by inhibiting the expression of Cc SOC1-like.However,Cc AGL24-like1,Cc AGL24-like2,Cc JOINTLESS-like1 and Cc JOINTLESS-like2 have a role in promoting flowering.This study preliminarily revealed the evolution and functional differentiation of the hickory StMADS11 subfamily genes,laying the foundation for our further research on the function and molecular regulatory network.