Establishment Of Camellia Sinensis Regeneration System And Functional Identification Of YABBY Genes Related To Leaf Development

The genetic transformation technology of tea plants has not been established so far,which is mainly influenced by the low Agrobacterium-transformation efficiency and the slow regeneration of tea plants.There have been reports of induction of hair roots based on the transformation of Agrobacterium rhizogenes.In the process of tea plants regeneration,the problems of low callus induction rate,high seedling deformity rate and slow seedling growth need to be solved urgently.In this research,we first optimized the tea callus induction system and the tea regeneration system.Then we compared the transient gene expression efficiency in different tissues and organs of tea plants.At last,the genes were screened to promote tea callus differentiation and plant regeneration.This research hopes to lay a theoretical and experimental basis for the establishment of tea plants genetic transformation system.The main conclusions are as follows:1.This study optimized the media for callus induction of different tissues and organs of tea plants,and selected suitable variety resources.The results show that No.4 medium is the best medium for inducing the callus of leaves.The screened varieties of tea trees are YH and YK.2.An adventitious bud induction system was established using tea leaves as explants,and a somatic embryo induction system was established using cotyledons as explants.The callus of leaves induction procedure is as follows: Induce callus on No.4 medium under dark conditions,subculture on No.3 medium,and then subculture once every month until the callus sprouts.The cotyledon callus induction process is as follows: Callus is induced in B5 medium under dark conditions,and the induced callus is subcultured to embryogenic callus on KBN medium,and then subcultured once every month until somatic embryos appear.Cell embryos were cut and placed on MSK medium for growth.3.The results showed that the hypocotyl root axis of tea were suitable materials for transient gene expression.4.Based on the genetic transformation system of Arabidopsis and tobacco,the functions of CsFILa,CsFILb,and CsYAB2 genes were verified.The results showed that the leaves of transgenic Arabidopsis plants overexpressing CsFILa and CsFILb were unrolled,narrow,long and shrink.Based on these results,we speculate that CsFILa,CsFILb,and CsYAB2 genes are involved in regulating the development of tea leaves.This work provides candidate genes for improving the genetic transformation system of tea plants for future works.