Cloning Of P5CS Gene From Carya Illinoensis And Its Expression Under NaCl Salt-stress

P5CS synthetase(△1-Pyrroline-5-carboxylate synthetas,P5CS) is the key enzyme of proline synthesis pathway in eukaryotic cells. It plays important roles on regulating the growth and salt-stress tolerance in plant. Based on the P5 CS gene sequences from other species,we cloned on P5 CS gene from the Caraya illinoensis,and studied the relative expression of P5 CS gene by using real-time quantitative PCR technology and some related physiological and photosynthesis responses under Na Cl salt-stress. The main conclusions of this study were as following:1.Using RT-PCR technology,a 1000 bp internal fragment was cloned on the Caraya illinoensis, named Ci P5 CS. Bioinformatics analysis of the gene revealed that its ORF is 795 bp and encoded for one polypeptide of 225 amino acids. Ci P5 CS maybe belong to actin family and exist in the nucleus with containing glutamic acid and glutamine kinase domain(GK) structure half aldehyde(GSA) domain structure. Moreover,homology analysis between Ci P5 CS gene sequence and the corresponding genes of other spieces showed that they have a high homology.And this also consistent with conservation of Ci P5CS’s evolutionary.This structural similarity suggested that they have more similar functions.2.using β-Actin gene controls on Ci P5 CS gene expression analysis.Its expression analysis by real-time quantitative PCR technology showed that Ci P5 CS gene was expressed in leaves of the Caraya illinoensis showed the low-high-low-high trend in general,With the Na Cl salt-stress being heavier,the expression effect was obvious.In addition,Suggesting its involvement in general response to salt resistance in Caraya illinoensis.3.In order to further study Caraya illinoensis seedings on the influence of salt resistance,measuring the physiological,biochemical and photosynthesis characteristics of several researches to infer its salt resistance power.In this study, the proline, soluble protein and malondialdehyde etc contents were increased and photosynthesis power gradual declined with increasing concentration of Na Cl salt-stress and rolongation of time,and each index rising trends is obvious.