Microelement Research Center, College of Resources & Environment, Huazhong Agricultural University, Wuhan, P. R. China.
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), MOA, Huazhong Agricultural University, Wuhan, P. R. China.
PLoS One. 2021 Jan 22;16(1):e0245600. doi: 10.1371/journal.pone.0245600. eCollection 2021.
The HAD superfamily is named after the halogenated acid dehalogenase found in bacteria, which hydrolyses a diverse range of organic phosphate substrates. Although certain studies have shown the involvement of HAD genes in Pi starvation responses, systematic classification and bioinformatics analysis of the HAD superfamily in plants is lacking. In this study, 41 and 40 HAD genes were identified by genomic searching in rice and Arabidopsis, respectively. According to sequence similarity, these proteins are divided into three major groups and seven subgroups. Conserved motif analysis indicates that the majority of the identified HAD proteins contain phosphatase domains. A further structural analysis showed that HAD proteins have four conserved motifs and specified cap domains. Fewer HAD genes show collinearity relationships in both rice and Arabidopsis, which is consistent with the large variations in the HAD genes. Among the 41 HAD genes of rice, the promoters of 28 genes contain Pi-responsive cis-elements. Mining of transcriptome data and qRT-PCR results showed that at least the expression of 17 HAD genes was induced by Pi starvation in shoots or roots. These HAD proteins are predicted to be involved in intracellular or extracellular Po recycling under Pi stress conditions in plants.
HAD 超家族的名称来源于在细菌中发现的卤代酸脱卤酶，该酶水解各种有机磷酸酯底物。尽管某些研究表明 HAD 基因参与了 Pi 饥饿反应，但植物 HAD 超家族的系统分类和生物信息学分析尚缺乏。在这项研究中，通过在水稻和拟南芥中的基因组搜索分别鉴定出 41 个和 40 个 HAD 基因。根据序列相似性，这些蛋白质分为三大组和七个亚组。保守基序分析表明，大多数鉴定出的 HAD 蛋白含有磷酸酶结构域。进一步的结构分析表明，HAD 蛋白具有四个保守基序和特定的帽结构域。在水稻和拟南芥中，较少的 HAD 基因显示出共线性关系，这与 HAD 基因的大量变异是一致的。在水稻的 41 个 HAD 基因中，28 个基因的启动子含有 Pi 响应顺式元件。对转录组数据的挖掘和 qRT-PCR 结果表明，至少有 17 个 HAD 基因的表达在地上部或根部受到 Pi 饥饿的诱导。这些 HAD 蛋白被预测在 Pi 胁迫条件下参与植物细胞内或细胞外 Po 循环。
