Research On The Salt Tolerance And Regulation Of Root Development On Heterologous Expression Of SaP5CS In Arabidopsis Thaliana Under Slat Stress

Soil salinization is one of the common abiotic stresses that affect the growth and development of plants,and it is also an important reason for reducing the yield of conventional crops.How to improve and use saline soil and increase crop yields is a major challenge for agricultural researchers,especially in crop breeding and plant stress resistance research.Higher soil salinity will interfere with the absorption of water and minerals,cause ion accumulation,disturb the metabolic balance,and cause the salt damage such as osmotic stress,ion stress,secondary oxidative stress in plants,it will affect the growth and development process of plant roots and aerial parts in different degrees.During the evolution process,higher plants have formed a variety of physiological and genetic response mechanisms to salt stress,such as plant apparent adaptation,osmotic adjustment,ion efflux and ion localization,and reactive oxygen species clearing strategies to reduce salt damage.Regulating the synthesis of organic osmotic adjustment substances such as proline,betaine,inositol,mannitol,and sorbitol is the common salt tolerance strategy for plants in response to the salt stress environments.Proline is a multifunctional amino acid and an important soluble organic substance involved in osmotic adjustment in plants.Relevant research shown that under salt stress,proline will accumulate in large quantities in plant,and it can protect the stability of protein metabolism,the structural integrity of nucleic acid molecules,regulate the osmotic balance and clear reactive oxygen species.Under salt stress,proline can alleviate the oxidative damage to root cells and reduce the adverse effects of salt stress on plant root growth.Under salt stress,the research on the molecular mechanism of proline synthesis and metabolism and proline's involvement in the regulation of plant root development is of great significance for interpreting the mechanism of plant salt tolerance,cultivating salt-tolerant crops suitable for the growth of salinized soil,and effectively utilizing salinized soil.In this study,heterologous overexpression of SaP5 CS transgenic Arabidopsis thaliana was used as material to screen homozygous transgenic lines and determine gene insert sites,combined with physiological phenotypes and gene expression analysis of salt tolerance and molecular regulation of proline anabolism on root development in homozygous transgenic Arabidopsis thaliana under salt stress.The main experimental results are as follows:(1)Screening homozygous lines and identification of insert sites on heterologous overexpression of SaP5 CS transgenic Arabidopsis thaliana.Using the Bar marker gene in the transgenic vector,homozygous transgenic lines were selected.The insert sites of homozygous lines were determined by TAIL-PCR technology.A total of 5 homozygous lines were screened and localized.(2)Research the salt tolerance on heterologous overexpression of SaP5 CS transgenic Arabidopsis thaliana.Transgenic type was treated with NaCl,photosynthesis-related chlorophyll content and chlorophyll fluorescence parameters;cellular osmotic adjustment related proline content,MDA content,soluble protein content and cell membrane permeability conductivity;reactive oxygen species clearing related APX enzyme activity,CAT enzyme activity,and GSH content was measured.The results show that because of the accumulation of proline,the tolerance of transgenic type under salt stress was enhanced.(3)Analyzed molecular mechanism of gene expression regulation that proline affects the root development on heterogeneous overexpression of SaP5 CS transgenic Arabidopsis thaliana under salt stress.Provides research train of thought,on the basis of the transcriptome data analysis processing,each in salt and exogenous proline mutant and wild type and transgenic Arabidopsis thaliana,to deal with the apparent changes in Arabidopsis thaliana,physiological and biochemical characteristics and related gene expression analysis and so on the basis of experimental results,to explore the proline molecular mechanism of the impact of root development in Arabidopsis thaliana,estimate the possible model in regulating gene expression.