《植物生理学报》 2016, 52(6): 948-956

芹菜赤霉素氧化酶基因AgGA2ox的克隆及非生物逆境下表达分析

冯凯, 王广龙, 黄莹, 徐志胜, 黄蔚, 熊爱生^*

南京农业大学作物遗传与种质创新国家重点实验室, 园艺学院, 农业部华东地区园艺作物生物学与种质创新重点实验室, 南京210095

通信作者：熊爱生；E-mail: xiongaisheng@njau.edu.cn

摘　要：

赤霉素(GAs)对植物生长发育有重要影响, 赤霉素氧化酶基因(GA2ox)在GAs合成过程中起重要调控作用。本文从不同芹菜(Apium graveolens)品种‘六合黄心芹’和‘文图拉’中分别克隆得到编码赤霉素氧化酶的基因AgGA2ox, 序列分析显示两个品种AgGA2ox基因均包含一个全长996 bp的开放阅读框, 编码331个氨基酸, 在核苷酸水平上有8个碱基位点的差异, 氨基酸水平上有2个位点的差异。AgGA2ox蛋白在‘六合黄心芹’和‘文图拉’两个品种中的相对分子质量分别为37 044.6和36 984.5, 理论等电点均为8.31。进化分析表明, 芹菜AgGA2ox在植物进化间具有高度保守性, 与西洋参(Panax quinquefolius)进化关系最为接近。实时定量PCR显示, AgGA2ox基因表达具有组织特异性, 在芹菜叶柄中表达量最高; 另外, AgGA2ox基因在4种非生物逆境条件[4°C低温、38°C高温、20%聚乙二醇(polyethylene glycol, PEG)及0.2 mol•L^-1 NaCl]下均有响应, 低温处理下AgGA2ox基因表达为明显上调, 高温、干旱和盐处理下AgGA2ox基因表达为下调。‘六合黄心芹’与‘文图拉’ Ag-GA2ox基因在逆境下的表达差异可能与不同品种抗逆性有关。

关键词：芹菜; 赤霉素; GA2ox; 非生物逆境; 表达分析

收稿：2016-03-21   修定：2016-05-21

资助：国家自然科学基金(31272175)、教育部新世纪优秀人才支持计划项目(NCET-11-0670)、江苏省自然科学基金杰出青年基金(BK20130027)和江苏高校优势学科建设项目(PAPD)。

Cloning and expression analysis of gibberellin oxidase gene AgGA2ox from Apium graceolens under abiotic stress treatments

FENG Kai, WANG Guang-Long, HUANG Ying, XU Zhi-Sheng, HUANG Wei, XIONG Ai-Sheng^*

State Key Laboratory of Crop Genetics and Germplasm Enhancement, Ministry of Agriculture Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in East China, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China

Corresponding author: XIONG Ai-Sheng; E-mail: xiongaisheng@njau.edu.cn

Abstract:

Gibberellins (GAs) have important impacts on the growth and development of plants. GA2ox gene plays a crucial role in regulating gibberellins synthesis. The AgGA2ox gene encoding GA oxidase was cloned from two celery cultivars, ‘Luhe Huangxinqin’ and ‘Ventura’, respectively. Sequence analysis revealed that Ag-GA2ox gene contained a full-length open reading frame of 996 bp, which encodes 331 amino acids. There are eight nucleotide sites and two amino acid residues differences in two cultivars. Relative molecular mass of Ag-GA2ox from ‘Luhe Huangxinqin’ and ‘Ventura’ were predicted to be 37 044.6 and 36 984.5, respectively. They showed the same theoretical isoelectric point (8.31). Phylogenetic analysis indicates that the GA2ox showed high evolutionary conservation among celery and other species, and the AgGA2ox was most closed to Panax quinquefolius. Quantitative real-time PCR analysis demonstrats that the AgGA2ox gene was tissue-specific in celery, and it mainly expressed in petiole. AgGA2ox gene was response to abiotic stress, such as low and high temperatures, drought, and salt stress. It was upregulated after low temperature treatment and downregulated after high temperature, drought, and salt treatments. Expression level differences of AgGA2ox between ‘Luhe Huangxinqin’ and ‘Ventura’ may be related to the different abilities to abiotic resistance.

Key words: Apium graceolens (celery); gibberellin; GA2ox; abiotic stress; expression analysis