Functional Research Of NAC Transcription Factor CaNAC064 In Pepper Under Temperature Stress

Pepper(Capsicum annuum L.)is one of the most important vegetables in the world.During its growth and development,it often encounters extreme temperature(low temperature,high temperature)which greatly reduces the yield.NAC(NAM,ATAF1/2,CUC2)transcription factors are plant-specific transcription factors.More and more studies have shown that their members are involved in various biological processes such as,the development of vascular bundles,the formation of secondary walls of anthers,plant senescence aging and environmental stress response.Especially in plants respond to abiotic stress plays an important regulatory role.In the early stage of the laboratory,the members of the NAC family of pepper were identified and the expression patterns of family members were analyzed.CaNAC064 the expression was significantly up-regulated under low temperature and high temperature stress.This experiment used CaNAC064 as a research object to explore the function of CaNAC064 in response to abiotic stress.The main results obtained are as follows:1.The sequence of the CaNAC064 gene and the structural features of the promoter region were analyzed.The full length of the gene was 1017 bp,encoding 338 amino acids,the molecular weight was 37.66 KDa,and the isoelectric point was 6.91.The promoter region contains multiple elements of action associated with hormone response and stress response.The CaNAC064 gene can be expressed by low temperature and high temperature.The gene was expressed in roots,stems,leaves,flowers,fruits and seeds of pepper,the highest expression in roots and low expression in fruits.Yeast transcriptional activation activity assay has transcriptional activation activity at the C-terminus and no transcriptional activity at the N-terminus.2.After silencing CaNAC064 by VIGS technology,it was treated at 4℃ and 42℃.From the Phenotype,the silenced plants were more wilting than the control plants.According to the analysis of physiological index data,the malondialdehyde content of the silenced plants was significantly higher than that of the control plants,and the POD activity and proline content were significantly lower than that of the control plants.DAB and NBT staining showed that the peroxide accumulated more in the silenced plants.The above results indicate the silencing of CaNAC064,which reduces the tolerance of pepper to low temperature and high temperature.3.Heterologous overexpression of CaNAC064 in Arabidopsis thaliana,transgenic lines and wild type(WT)lines were treated at 4 ℃ and 42 ℃,and found that the malondialdehyde content and relative conductivity of the transgenic lines were lower than WT;The POD activity is higher than WT.Overexpression of CaNAC064 enhances the cold tolerance and heat tolerance of Arabidopsis.4.A total of 45 interacting that may interact with CaNAC064 were initially identified by yeast two-hybrid screening library.The Remorin protein,low temperature-induced haplo-proteinase,heat shock protein and serine carboxypeptidase were selected for point-to-point rotation verification,and it was confirmed that these four proteins may interact with CaNAC064.