School of BioSciences, The University of Melbourne, Melbourne, VIC 3010, Australia.
Genes (Basel). 2021 Apr 27;12(5):653. doi: 10.3390/genes12050653.
Effective maintenance of plant iron (Fe) homoeostasis relies on a network of transcription factors (TFs) that respond to environmental conditions and regulate Fe uptake, translocation, and storage. The iron-related transcription factor 3 (IRO3), as well as haemerythrin motif-containing really interesting new gene (RING) protein and zinc finger protein (HRZ), are major regulators of Fe homeostasis in diploid species like () and rice ( L.), but remain uncharacterised in hexaploid bread wheat ( L.). In this study, we have identified, annotated, and characterised three homoeologs and six and homoeologs in the bread wheat genome. Protein analysis revealed that TaIRO3 and TaHRZ proteins contain functionally conserved domains for DNA-binding, dimerisation, Fe binding, or polyubiquitination, and phylogenetic analysis revealed clustering of TaIRO3 and TaHRZ proteins with other monocot IRO3 and HRZ proteins, respectively. Quantitative reverse-transcription PCR analysis revealed that all and homoeologs have unique tissue expression profiles and are upregulated in shoot tissues in response to Fe deficiency. After 24 h of Fe deficiency, the expression of homoeologs was upregulated, while the expression of homoeologs was unchanged, suggesting that TaHRZ functions upstream of TaIRO3 in the wheat Fe homeostasis TF network.
有效的植物铁（Fe）稳态维持依赖于转录因子（TFs）网络，该网络响应环境条件并调节 Fe 的吸收、转运和储存。铁相关转录因子 3（IRO3）以及含血红素基序的真核生物新基因（RING）蛋白和锌指蛋白（HRZ）是二倍体物种（如）和水稻（ L.）中 Fe 稳态的主要调节剂，但在六倍体面包小麦（ L.）中尚未被描述。在这项研究中，我们在面包小麦基因组中鉴定、注释和表征了三个 同系物和六个 同系物和 同系物。蛋白分析表明，TaIRO3 和 TaHRZ 蛋白包含功能保守的 DNA 结合、二聚化、Fe 结合或多泛素化结构域，系统发育分析表明 TaIRO3 和 TaHRZ 蛋白分别与其他单子叶 IRO3 和 HRZ 蛋白聚类。定量反转录 PCR 分析表明，所有 同系物和 同系物都具有独特的组织表达谱，并在 Fe 缺乏时上调。在 Fe 缺乏 24 h 后， 同系物的表达上调，而 同系物的表达不变，表明 TaHRZ 在小麦 Fe 稳态 TF 网络中位于 TaIRO3 的上游。
