Cloning And Expression Analysis Of Auxin Transport Carrier Family Genes At Different Winter Dormant Stages Of Bud In Tea Plant(Camellia Sinensis)

Bud dormancy broadly refers to the visible growth cessation of plant shoots, it is a beneficial biological trait for plant to adapt inappropriate environmental conditions among the seasons change due to long time natural evolution. The plants will resume active growth when external environment or internal conditions reversal. Tea plant is an important economic crop. In tea production, it is well known that the earlier tea picking the more valuable tea product. So, breeding early sprouting varieties can improve the economic benefits of tea production. The bud dormancy of tea plant is affected by multiple factors of which the endogenous hormone of auxin is an important one. Auxin transport carrier proteins contribute to the auxin asymmetrical distribution in plant tissues or organs, and play a wide range of physiological effects in plant growth and development processes. Therefore exploring the relationship between auxin transport carrier gene family and bud dormancy in tea plant will produce important theoretical and practical significances in early germplasm resources screening.In this study, on the basis of sequence resource from tea plant cold acclimation transcriptome sequencing in our previous research, we obtained 6 full length c DNA sequences of auxin transport carrier genes by RACE PCR combining with RT-PCR. And then we studied their expression changes under natural dormancy triansition by real-time fluorescent quantitative PCR technology, to provide evidences for illuminating the relationship between auxin transport carrier gene and winter bud dormancy transition.1. The full length cDNA sequences of 6 auxin transport carrier genes were successfully cloned from tea plant using RACE-PCR and RE-PCR, and submitted to NCBI database. Bioinformatics analysis results showed that the six genes were grouped into three subfamilys, respectively named CsPIN3,CsAUX1, CsLAX1, CsLAX3, CsPILS2, and CsPILS7. Amino acid sequence analysis further showed that all of six genes are the typical membrane proteins and contain multiple transmembrane helicals,which adapt to their functions as auxin transport carrier.2. We analyzed the tissue-specific expression of auxin transport carrier genes by q RT-PCR in different organs, and results showed that the auxin transport carrier genes had obvious different expression patterns in roots, stems, leaves, flowers, buds.3. The expressions of auxin transport carrier genes were detected by qRT-PCR during the different phases of winter dormancy, and results indicated that the expression levels of CsPIN3 and AUX/LAX at growth stage was higher than that at dormant stage(initial dormant stage to expanding stage), and an obvious expression jump was detected at bud sprouting stage. CsPILS2 has similar expression changes with AUX/LAX family genes, and CsPILS7 had low expression both in winter dormancy formation and release stages, but slightly higher was detected in dormancy formation stage comparing with dormancy relsease.