资阳香橙砧木CjSPL基因家族鉴定及表达模式分析

Identification of CjSPL gene family in Ziyang Xiangcheng rootstock and expression pattern analysis

摘要:

鳞片启动子结合类蛋白squamosa promoter binding protein-like， SPL）家族是一类参与调控植物生长发育以及响应环境胁迫的重要转录因子，但在柑橘等多年生果树中的研究较少。本研究以柑橘一种重要的砧木——资阳香橙（Citrus junos Sieb.ex Tanaka）为材料，基于plantTFDB转录因子数据库和甜橙基因组数据库鉴定并克隆出资阳香橙15个SPL家族基因，命名为CjSPL1–CjSPL15。序列分析表明，CjSPLs的开放阅读框（open reading frame，ORF）长度为393–2 865 bp，编码130–954个氨基酸；系统进化树将15个CjSPLs分为9个亚家族；基因结构和保守结构域分析预测出20个不同的保守motif和SBP基本结构域；启动子顺式作用元件分析预测出20种启动子元件，其中包含植物生长发育、非生物胁迫及次生代谢物相关元件。通过实时荧光定量PCR （real-time fluorescence quantitative PCR，qRT-PCR）分析了CjSPLs在干旱、盐和低温胁迫下的表达模式，较多CjSPLs在胁迫处理后显著上调表达。本研究为后续深入研究柑橘及其他果树SPL家族转录因子功能提供参考。

Abstract:

Squamosa promoter binding protein-like (SPL) family is a group of important transcription factors involved in the regulation of plant growth and development and the response to environmental stress, but there are few studies in perennial fruit trees such as citrus. In this study, Ziyang Xiangcheng (Citrus junos Sib.ex Tanaka), an important rootstock of Citrus, was used as the material for analysis. Based on plantTFDB transcription factor database and sweet orange genome database, 15 SPL family members were genome-widely identified and cloned from Ziyang Xiangcheng, and named CjSPL1-CjSPL15. Sequence analysis showed that the open reading frame (ORF) length of CjSPLs ranged from 393 bp to 2 865 bp, encoding 130-954 amino acids. Phylogenetic tree divided 15 CjSPLs into 9 subfamilies. Gene structure and conserved domain analysis predicted 20 different conserved motifs and SBP basic domains. Analysis of cis-acting promoter elements predicted 20 different promoter elements, including those related to plant growth and development, abiotic stress and secondary metabolites. The expression patterns of CjSPLs under drought, salt and low temperature stresses were analyzed by real-time fluorescence quantitative PCR (qRT-PCR), and many CjSPLs were significantly up-regulated after stress treatment. This study provides a reference for further study on the function of SPL family transcription factors in citrus and other fruit trees.