Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.
Isolation and characterization of a catalase gene "HuCAT3" from pitaya (Hylocereus undatus) and its expression under abiotic stress.
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DOI：
10.1016/j.gene.2015.03.007
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发表时间：
2015-05
期刊：
影响因子：
3.5
通讯作者：
Qiong Nie;Guo-Li Gao;Qing-jie Fan;G. Qiao;X. Wen;Tao Liu;Zhijun Peng;Yongqiang Cai
中科院分区：
文献类型：
--
作者：
Qiong Nie;Guo-Li Gao;Qing-jie Fan;G. Qiao;X. Wen;Tao Liu;Zhijun Peng;Yongqiang Cai
非生物胁迫通常导致H2 O2在植物体内积累，并产生有害影响。过氧化氢酶可能通过解毒这种过量的H2 O2在植物细胞中发挥关键的保护作用。火龙果（Hylocereus undatus）对干旱、高温、土壤贫瘠等非生物胁迫具有较强的耐受性，具有广泛的生态适应性。然而，火龙果过氧化氢酶基因（HuCAT）参与非生物胁迫的耐受性是未知的。本研究利用基因芯片技术和RACE方法从火龙果中克隆了一个全长HuCAT 3 cDNA（1870 bp）。其cDNA序列和推导的氨基酸序列与其它植物过氧化氢酶的同源性分别为73-77%和75-80%。HuCAT 3含有保守的过氧化氢酶家族结构域和催化位点。两两比较和系统发育分析表明，HuCAT 3与枇杷CAT最相似，其次是龙眼CAT和烟草CAT 1。表达谱分析表明，HuCAT 3主要在绿色子叶和成熟茎中表达，受H2 O2、干旱、低温和盐胁迫的调控，但其表达模式和最大表达量因胁迫类型而异。随着胁迫时间的延长，HuCAT活性逐渐升高，其变化趋势与HuCAT 3 mRNA丰度一致（干旱胁迫0. 5 d除外）;低温胁迫下HuCAT 3 mRNA的升高和HuCAT活性的变化也与4种基因型的耐寒性相一致。以上结果证实了HuCAT 3在火龙果非生物胁迫响应中的重要作用。这对从分子水平上了解火龙果对非生物胁迫的高度耐受性有一定的帮助。
Abiotic stresses usually cause H2O2accumulation, with harmful effects, in plants. Catalase may play a key protective role in plant cells by detoxifying this excess H2O2. Pitaya (Hylocereus undatus) shows broad ecological adaptation due to its high tolerance to abiotic stresses, e.g. drought, heat and poor soil. However, involvement of the pitaya catalase gene (HuCAT) in tolerance to abiotic stresses is unknown. In the present study, a full-lengthHuCAT3cDNA (1870 bp) was isolated from pitaya based on our previous microarray data and RACE method. The cDNA sequence and deduced amino acid sequence shared 73–77% and 75–80% identity with other plant catalases, respectively. HuCAT3 contains conserved catalase family domain and catalytic sites. Pairwise comparison and phylogenetic analysis indicated thatHuCAT3is most similar to Eriobotrya japonicaCAT, followed by Dimocarpus longanCATand Nicotiana tabacumCAT1. Expression profile analysis demonstrated thatHuCAT3is mainly expressed in green cotyledons and mature stems, and was regulated by H2O2, drought, cold and salt stress, whereas, its expression patterns and maximum expression levels varied with stress types. HuCAT activity increased as exposure to the tested stresses, and the fluctuation of HuCAT activity was consistent withHuCAT3mRNA abundance (except for 0.5 days upon drought stress).HuCAT3mRNA elevations and HuCAT activities changes under cold stress were also in conformity with the cold tolerances among the four genotypes. The obtained results confirmed a major role ofHuCAT3in abiotic stress response of pitaya. This may prove useful in understanding pitaya's high tolerance to abiotic stresses at molecular level.