《植物生理学报》 2009, 45(7): 657-662

彩叶草中一个富亮氨酸重复相关蛋白基因SsLRP 的克隆和分析

祝钦泷^1,2, 李名扬^2,*

1 华南农业大学生命科学学院, 广东省植物功能基因组与生物技术重点实验室, 广州510642; 2 西南大学园艺园林学院, 西南大学花卉研究所, 重庆400716

通信作者：李名扬；E-mail: limy@swu.edu.cn；Tel: 023-68251250

摘　要：

根据彩叶草叶片小型 EST 库中一条具有 1 个富亮氨酸重复(leucine-rich repeat, LRR)结构域的 EST 序列, 采用 RACE 与文库结合的方法, 克隆了1个具有5个LRR结构域的全长cDNA, SsLRP (LRR-Related Protein) (GenBank登录号FJ787729)。 SsLRP cDNA 全长 1 024 bp, 包含一个 657 bp 的 ORF 框, 编码 218 个氨基酸。其 5’-UTR 区含有 2 个终止子 TAG, 3’-UTR 区 具有推测的加尾信号 AATAAA。SsLRP 蛋白 N 端具有的信号肽和保守的亮氨酸拉链结构域, 具有 5 个保守的 LRR 结构域, 多个磷酸化位点和 N- 糖基化位点。多序列比对和系统进化分析表明, SsLRP 与番茄 SlLRP 同源性最高。二级结构和三级 结构预测表明, SsLRP的功能可能与保守的LRR结构域密切相关, 推测该基因可能参与蛋白间的相互作用与信号识别。RT- PCR 分析表明, SsLRP 与番茄SlLRP 具有相似的表达模式, 在正常植株的根、茎、叶和花中都有表达, 在受菌核病感染植株 的茎和叶中表达上调。

关键词：彩叶草; 富亮氨酸重复蛋白; SsLRP基因

收稿：2009-03-18   修定：2009-06-01

Molecular Cloning and Analysis of a Novel Leucine-Rich Repeat Related Protein Gene, SsLRP, from Solenostemon scutellarioides (L.) Codd

ZHU Qin-Long^1,2, LI Ming-Yang^2,*

¹Key Laboratory of Plant Functional Genomics and Biotechnology of Guangdong Province, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China;²Institute of Ornament Plants, College of Horticulture and Landscape, Southwest University, Chongqing 400716, China

Corresponding author: LI Ming-Yang; E-mail: limy@swu.edu.cn; Tel: 023-68251250

Abstract:

According to a EST sequence with a LRR (leucine-rich repeat) domain from Solenostemon scutellarioides, a novel leucine-rich repeat prelated rotein (LRP) gene with 5 LRRs, denoted SsLRP (GenBank Accession No. FJ787729), was rapidly cloned using a strategy of RACE combined with cDNA library. The full length of SsLRP was 1 024 bp and contained a 657 bp open reading frame (ORF) encoding a 218 amino acid protein. Two stop codons (TAG) were found in 5’-UTR and one possible polyadenylation signal, AATAAA, was found in 3’-UTR. The SsLRP contained a predicted signal peptide and a conserved LZ (leucine zipper) domain in the N-terminal region, five conserved LRR domains, and multiple phosphorylation sites and N-linked glycosylation sites. Multiple sequence alignment and phylogenetic analysis showed that SsLRP shared high homology with tomato SlLRP, and belonged to the same subfamilies of LRPs. The prediction analysis of secondary structure and three dimensional structures of SsLRP showed that the possible function of the protein was decided by the multiple LRR domains, and involved in protein-protein interactions and signal perception. The RT-PCR analysis showed that SsLRP and SlLRP had the same expression pattern. SsLRP was expressed in all normal tissues, and up-regulated at high levels in diseased steam and leaves infected with Sclerotinia sclerotiorum.

Key words: Solenostemon scutellarioides; leucine-rich repeat protein; SsLRP