title: The bHLH transcription factor bHLH104 interacts with IAA-LEUCINE RESISTANT3 and modulates iron homeostasis in Arabidopsis.
abstract: Iron (Fe) is an indispensable micronutrient for plant growth and development. The regulation of Fe homeostasis in plants is complex and involves a number of transcription factors. Here, we demonstrate that a basic helix-loop-helix (bHLH) transcription factor, bHLH104, belonging to the IVc subgroup of bHLH family, acts as a key component positively regulating Fe deficiency responses. Knockout of bHLH104 in Arabidopsis thaliana greatly reduced tolerance to Fe deficiency, whereas overexpression of bHLH104 had the opposite effect and led to accumulation of excess Fe in soil-grown conditions. The activation of Fe deficiency-inducible genes was substantially suppressed by loss of bHLH104. Further investigation showed that bHLH104 interacted with another IVc subgroup bHLH protein, IAA-LEUCINE RESISTANT3 (ILR3), which also plays an important role in Fe homeostasis. Moreover, bHLH104 and ILR3 could bind directly to the promoters of Ib subgroup bHLH genes and POPEYE (PYE) functioning in the regulation of Fe deficiency responses. Interestingly, genetic analysis showed that loss of bHLH104 could decrease the tolerance to Fe deficiency conferred by the lesion of BRUTUS, which encodes an E3 ligase and interacts with bHLH104. Collectively, our data support that bHLH104 and ILR3 play pivotal roles in the regulation of Fe deficiency responses via targeting Ib subgroup bHLH genes and PYE expression.
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Jie
authors: J
authors: Zhang
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Bing
authors: B
authors: Liu
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Mengshu
authors: M
authors: Li
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Dongru
authors: D
authors: Feng
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Honglei
authors: H
authors: Jin
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Peng
authors: P
authors: Wang
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Jun
authors: J
authors: Liu
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Feng
authors: F
authors: Xiong
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China.
authors: Jinfa
authors: J
authors: Wang
authors: State Key Laboratory of Biocontrol and Collaborative Innovation Center of Genetics and Development, Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, 510275 Guangzhou, People's Republic of China wanghb@mail.sysu.edu.cn.
authors: Hong-Bin
authors: http://orcid.org/0000-0003-4957-0509
authors: HB
authors: Wang
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D017343:Genes, Plant; D006706:Homeostasis / Q000187:drug effects*; D007501:Iron / Q000494:pharmacology*; D000090463:Iron Deficiencies; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D059372:Nucleotide Motifs / Q000235:genetics; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D060888:Real-Time Polymerase Chain Reaction; D012987:Soil
chemical_list: D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D007501:Iron; D012987:Soil; C000606190:ILR3 protein, Arabidopsis; C000606189:bHLH104 protein, Arabidopsis