关键词: 苎麻, 果胶, GalAT, 克隆, BLAST, 实时定量PCR法

Abstract:

【Objective】 The aim of this study was to isolate the cDNA partial sequence of key enzyme gene GalAT for pectin biosynthesis in ramie [Boehmeria nivea (L.) Gaud], and understanding of the expression of GalAT gene in different tissues of ramie. 【Method】 Degenerate primer RT-PCR method was used to clone GalAT gene, bioinformatics methods were used to analyze cDNA sequence obtained and putative amino acid sequence, and fluorescence real time quantitative PCR method were used to study the expression of GalAT gene in different tissues. 【Result】 The cDNA partial sequence of GalAT gene from ramie variety Zhongzhu 1 was cloned. The cloned cDNA was 986 bp in length which encoded 328 amino acid sequences (GenBank accession number: EU 131377). This is the firstly reported GalAT gene in ramie. The cDNA sequence and putative amino acid sequence of GalAT shared high identity with previously reported Arabidopsis thaliana galacturonosyltransferase 4: 77 % and 83%, respectively; and the putative amino acid sequence and A. thaliana's galacturonosyltransferase 4 was gather to a same group; GalAT can be expressed in different kinds of ramie tissues, and its mRNA accumulated most abundantly in root. 【Conclusion】 It was inferred that the sequence obtained is cDNA partial sequence of GalAT gene, and can express in any tissue of ramie. GalAT mRNA accumulated abundantly most in root and GalAT expression in ramie tissues was root>leaf>bast>or≈xylem.

Key words: ramie, pectin, GalAT, clone, BLAST, real-time quantitative PCR analysis