胡萝卜抗坏血酸过氧化物酶基因的分离及其对非生物胁迫的响应.

[Objectives]Ascorbate peroxidase(APX)removes excess plant peroxides by using an electron donor from ascorbic acid,which is an essential mechanism in response to abiotic stress. The aim of the paper is to study the response of DcAPX gene in the process of resisitance to abiotic stress. [Methods]The DcAPX gene was cloned from carrot variety‘Kurodagosun’. Expression profiles under high and low temperature,drought,and salinity treatments were performed to further understand the roles of the gene in response to abiotic stress in carrot. The gene was submitted to GenBank and the accession number is KR364573. [Results]Sequence analysis indicated that the length of DcAPX gene was 753 bp,which encoded 250 amino acids. It is predicted that the relative molecular mass of its protein was 27.76×103,and pI was 5.65. Amino acid sequence comparison showed that the evolutionary relationship of DcAPX from carrot was close to Pimpinella brachycarpa,which both belong to the Apiaceae family. Structure analysis showed that DcAPX was made up of 38.40% alpha helix,10.40% extended strand,and 51.20% random coil. Analysis on three-dimension structure implied that the enzyme was composed of 10 alpha helixes and 4 beta sheets. Quantitative real-time PCR analysis demonstrated that carrot DcAPX gene was tissue-specific,and had the highest expression level in the leaf. [Conclusions]DcAPX gene was significantly induced by abiotic stress,and the gene may play important roles in resistance against abiotic stress. [ABSTRACT FROM AUTHOR]