title: The bHLH transcription factor HBI1 mediates the trade-off between growth and pathogen-associated molecular pattern-triggered immunity in Arabidopsis.
abstract: The trade-off between growth and immunity is crucial for survival in plants. However, the mechanism underlying growth-immunity balance has remained elusive. The PRE-IBH1-HBI1 tripartite helix-loop-helix/basic helix-loop-helix module is part of a central transcription network that mediates growth regulation by several hormonal and environmental signals. Here, genome-wide analyses of HBI1 target genes show that HBI1 regulates both overlapping and unique targets compared with other DNA binding components of the network in Arabidopsis thaliana, supporting a role in specifying network outputs and fine-tuning feedback regulation. Furthermore, HBI1 negatively regulates a subset of genes involved in immunity, and pathogen-associated molecular pattern (PAMP) signals repress HBI1 transcription. Constitutive overexpression and loss-of-function experiments show that HBI1 inhibits PAMP-induced growth arrest, defense gene expression, reactive oxygen species production, and resistance to pathogen. These results show that HBI1, as a component of the central growth regulation circuit, functions as a major node of crosstalk that mediates a trade-off between growth and immunity in plants.
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305.
authors.forename: Min
authors.initials: M
authors.lastname: Fan
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Bai
authors.forename: Jung-Gun
authors.initials: JG
authors.lastname: Kim
authors.forename: Tina
authors.initials: T
authors.lastname: Wang
authors.forename: Eunkyoo
authors.initials: E
authors.lastname: Oh
authors.forename: Lawrence
authors.initials: L
authors.lastname: Chen
authors.forename: Chan Ho
authors.initials: CH
authors.lastname: Park
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Son
authors.forename: Seong-Ki
authors.initials: SK
authors.lastname: Kim
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Mudgett
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism; D005408:Flagellin / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008954:Models, Biological; D057865:Plant Immunity / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D051192:Receptors, Pattern Recognition / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D060406:Brassinosteroids; D005408:Flagellin; D051192:Receptors, Pattern Recognition; C000592616:HBI1 protein, Arabidopsis