Cloning And Expression Analysis Of Genes Related To Nitrogen Transporter In Tea Plants(Camellia Sinensis)

Nitrogen is an important and indispensable element in plant growth and development, it’s the composition element of many important component elements in plants. Nitrate and ammonium are the main nitrogen sources plants could absorb and use directly, by plant nitrogen nutrition absorbing biological macromolecules of transport ammonium nitrate and ammonium transporters. Tea plant is perennial plant for leaf use, every spring, N could be lost because of tea plucking periodically. In order to satisfy the normal growth need of tea tree next year, a lot of nitrogen fertilizer are applied to tea garden. However it also brings much negative effects, such as economic waste, the increase of production cost and environment pollution. Molecular biology techniques can rapid the tea varieties breeding of high nitrogen efficiency, it’s very significant for the work of tea plant breeding.The cDNA of NRT gene in Camellia sinensis was amplified via RACE technology by the EST screened from NCBI, and the cDNA was preliminary bio informatics predicted and analysed. Expression level of NRT, AMT1.1 and AMT1.2 among different cultivars and different tissues were analysed by fluorescence quantitative PCR with camellia sinensis cv.FuZao No.2, Longjinchangye, and Shuchazao as materials. The main research results are as follows:1. In this study, the cDNA full-length of NRT gene in Camellia sinensis, named CsNRT, was 2061bp, with 1818 bp ORF encording 605 amino acid, the accession number was KJ160503 in GenBank.2. The deduced CsNRT protein was hydrophobic protein, it contained 12 transmenbrane domains, among which the sixth and seventh were connected by large hydrophilic ring.Six conservative binding sites of protein kinase C were found, pre and post were two structure domains in MFS family.3. Expression level of NRT, AMT1.1 and AMT1.2 among different cultivars and different tissues were analysed by fluorescence quantitative PCR with camellia sinensis cv.FuZao No.2, Longjinchangye, and Shuchazao as materials. The results indicated that the three genes exhibited tissue-specificity and mainly distributed in roots.4. Under different NO3+ application levels, a pot experiment with three tea cultivars one-year-old were conducted to study expression levels of CsNRT in roots by sampling the different times. Results indicate that Camellia sinensis cv.Longjinchangye respon: to low and medium concentrations strongly, Camellia sinensis cv. FuZao No.2 responsed to medium and high concentrations strongly, while there was no abovious changes for Camellia sinensis cv. Shuc hazao.5. Under different NH4+ application levels, a pot experiment with three tea cultivars of one-year-old were conducted to study expression levels of AMT1.1 and AMT1.2 by sampling at the different times. Results indicate that The expression level of ANT1;1 in roots didn’t chage at different time. While there were changes in stem and leaf, in different NH4+ concentrations, expression levels of the two genes both increased first, then decreased with time increased.