毛竹APX家族基因鉴定和表达分析

为了解毛竹(Phyllostachys edulis)抗坏血酸过氧化物酶(ascorbate peroxidase, APX)基因家族成员在不同组织和非生物胁迫下的表达模式,利用生物信息学方法从毛竹基因组数据库中鉴定得到7条APX同工酶基因(PeAPXs),根据亚细胞定位预测结果可分为3个亚类。各个基因启动子序列中存在低温、干旱以及光响应元件。毛竹PeAPXs在7个组织中的表达丰度不同,具有组织特异性。qRT-PCR结果表明,在干旱、盐和低温胁迫下各基因的表达模式存在着较大差异,其中PeAPX2在3种胁迫下均维持着较高的表达水平;低温胁迫对PeAPXs有诱导作用,其表达量均呈上调趋势;干旱胁迫下,PeAPX1的表达量下调,未检测到PeAPX3、PeAPX6、PeAPX7表达;盐胁迫下,除PeAPX3和PeAPX6外,其余基因表达量上调。因此,毛竹APX基因可能参与到不同的非生物胁迫过程并在毛竹的生长发育阶段发挥着重要的作用。

Identification and Expression Analysis of the APX Gene Family in Phyllostachys edulis

In order to understand the expression patterns in different tissues and under abiotic stress of ascorbate peroxidase (APX) gene family in Phyllostachys edulis, seven PeAPXs were obtained from the genomic database of P. edulis. PeAPXs could be divided into three subfamilies, including cytoplasmic, peroxisome and chloroplast/mitochondrion types based on the predictions of subcellular localizations. There were drought, cold, and light response elements in promoter sequences of each gene, such as Box-4 and G-Box. The expressions of PeAPXs were different among seven tissues, showing tissue specificity. qRT-PCR revealed that there were great differences in the expression pattern of each gene under drought, salt and low temperature stress. The expression of PeAPX2 was maintained at high level under three stresses. The expression of PeAPXs were induced by low temperature stress. Under drought stress, the expression of PeAPX1 was down-regulated, while the expressions of PeAPX3, PeAPX6 and PeAPX7 were not detected. Under salt stress, all of PeAPXs were up-regulated except PeAPX3 and PeAPX5. Therefore, PeAPXs may be involved in different abiotic stress processes and play an important role in the growth and development stage of P. edulis.