Study On The Molecular Mechanism Of Proline Metabolism Under Stress Of Tea Plant

Tea plant(Camellia sinensis(L.)O.Kuntze)is a perennial evergreen plant that likes shade,wet and warm.Tea plants undergo various abiotic stresses during their growth and development.Plants accumulate some osmotic substances to protect themselves under abiotic stresses.Proline is one of the most common osmotic substances.At present,the specific mechanism of proline metabolism in tea plants under abiotic stress is still unclear,and there are differences in research results.Therefore,it has important theoretical value to explore the physiological and metabolic response of proline under tea tree stress and its molecular mechanism.In this paper,the gene clone tea tree proline metabolizes a conservative sequence of key genes through genome and transcription group data comparison screening.Selected a year-old tea early seedling,as PEG simulation drought stress,low temperature stress and salt stress treatment of the test materials,at different stress times to collect root,stem,leaf samples,determine the sample free proline content and proline metabolism pathway of the metabolic key enzyme activity,but also extracted the sample RNA,made the proline metabolism pathway key gene q PCR expression analysis.In order to study the proline metabolism of tea trees under low temperature stress,a further 1-year-old YH9 and 1-year-old SCZ seedlings were selected,as a low temperature stress test material for different cold-resistant varieties;The content of free proline and the expression of proline metabolites were determined in each of the above groups.1.Successfully cloned Cs OAT,Cs P5 CR,Cs Pro DH and Cs P5 CDH gene conservative sequence,wherein Cs OAT contains 1422 bp open reading box,coding a protein consisting of 473 amino acids,protein molecular weight of 52.28 k Da,isoelectric point of 7.17.Cs P5 CR contains an 834 bp open reading box encoded a protein consisting of 277 amino acids with a protein molecular weight of 28.65 k Da and an isometric point of 8.73.Cs Pro DH contains a 1440 bp open reading box that encodes a protein consisting of 479 amino acids with a protein molecular weight of53.41 k Da and an isometric point of 8.04.Cs P5 CDH contains a 1779 bp open reading box that encodes a protein consisting of 592 amino acids with a protein molecular weight of 66.08 k Da and an isometric point of 7.95.Through bioinformatics analysis,it was found that the four encoded proteins were hydrophilic proteins,no transmembrane structure,no signal peptides,and the discovery of the construction system evolutionary tree were closely related to Chinese kiwi.2.In the normal growth environment,different seedlings of Shu tea morning tea leaves free proline content comparison results: 1 year> 3 years> perennial.Comparison of free proline content of tea tree organs: stem > leaf > buds > roots.3.Under 3 kinds of adversity stress treatment,compared to low temperature stress,tea tree for PEG simulated drought stress and salt stress treatment more sensitive,the accumulation of free proline more.Compared with the three organs of root,stem and leaf,the content of free proline accumulated more in the root and leaf under stress treatment,and the accumulation of relatively small in the stem.4.Under 3 kinds of stress treatment,P5 CS enzymes play a major role,the activity increased significantly during the stress period,the expression of Cs P5 CS gene significantly increased,and promoted the increase of free proline content.OAT enzyme in salt stress treatment,the activity increased significantly,and the Cs OAT gene significantly increased.P5 CR enzyme in the stress of the activity increased,Cs P5 CR gene also increased expression,generally in the pre-stress play.The activity of degradation pathway enzyme pro DH and P5 CDH enzymes and the expression of Cs Pro DH and Cs P5 CDH gene were inhibited during the stress process.5.Under low temperature treatment,SCZ variety leaves than in the YH9 leaves accumulated more free proline content,the two proline metabolic gene expression trend is similar.Under low temperature treatment,the seedling accumulates more free proline content than the leaf of the seedling,and the gene expression trend of the two is similar.Under low temperature treatment,pre-sprayed acid,salicylic acid and melatonin will promote the accumulation of free proline content of tea leaves.