碎米荠超氧化物歧化酶基因家族成员的鉴定和分析

为了解碎米荠(Cardamine hirsuta)的SOD基因特征，对SOD家族成员的基因结构、染色体定位、系统进化关系进行了分析，对顺式作用元件和蛋白结构进行了预测，并利用qRT-PCR技术检测各家族成员的组织表达模式。结果表明，碎米荠基因组中共有10个SOD基因(ChSODs)，包括6个Cu/Zn-SOD、3个Fe-SOD和1个Mn-SOD。编码的ChSODs蛋白有57~ 324个氨基酸，分子量为6 419.41~34 659.01 kDa，理论等电点为4.92~9.60；系统进化树分析表明，碎米荠的ChSOD与拟南芥的AtSOD的同源性较高；ChSODs在根、茎、叶中均有表达，且在叶中高表达，其中CARHR085500和CARHR256690在叶和茎中表达量较高；顺式作用元件预测表明，碎米荠SOD响应多种非生物胁迫，其中对ABA和低温胁迫较为敏感; ChSODs蛋白质的二级和三级结构具有差异性。这表明碎米荠SOD基因在抗氧化过程中发挥重要作用。

Identification and Analysis of Superoxide Dismutase Gene Family Members of Cardamine hirsuta

In order to understand the characteristics of SOD gene in Cardamine hirsuta, the gene structure, chromosome location, phylogenetic relationship of SOD gene family were analyzed, the cis-acting element and protein structure were predicted, and the tissue expression patterns of the gene family numbers were measured by qRT-PCR. The results showed that a total of 10 SOD genes, named ChSODs, were identified from C. hirsuta genome, including 6 Cu/Zn-SOD, 3 Fe-SOD and 1 Mn-SOD. The amino acid numbers of ChSODs ranged from 57 to 324, with molecular weight from 6 419.41 to 34 659.01 kDa, and theoretical isoelectric point from 4.92 to 9.60. Phylogenetic tree showed that ChSOD had close relation with AtSOD of Arabidopsis. There were expression of ChSOD in root, stem and leaf, and the expression in leaves was high. Furthermore, the expression of CARHR085500 and CARHR256690 were high in leaves and stems. There were cis-acting elements responded to various abiotic stresses, in especial to ABA and low temperature stress. The secondary and tertiary structures of ChSODs were different. Therefore, these indicated that SOD gene of C. hirsuta play an important role in antioxidant process.