Project description:Differentiation of Arabidopsis guard cells: analysis of the networks incorporating the basic helix-loop helix transcription factor, FAMA
Project description:A cascade of basic helix-loop-helix transcription factors guide tapetal cell development in maize anthers, using proteins conserved in Arabidopsis and rice but deployed with a distinctive timing. Anthers were dissected and staged to be 1500 μm in length (+/- 100 μm) and samples were compared between mutants and fertile siblings on an Agilent 4x44 custom microarray. Analysis included MS32 which is another basic helix-loop-helix factor that acts later during tapetal differentiation.
Project description:The trade-off between growth and immunity is crucial for survival in plants. An antagonistic interaction has been observed between the growth-promoting hormone brassinosteroid and pathogen associated molecular pattern (PAMP) signals, which induce immunity but inhibit growth, however the underlying molecular mechanism has remained unclear. The PRE-IBH1-HBI1 triple helix-loop-helix/basic helix-loop-helix (HLH/bHLH) cascade has been shown to mediate growth responses to several hormonal and environmental signals, but its downstream targets and role in immunity remain unknown. Here, we performed genome-wide analyses of HBI1 target genes in Arabidopsis. The results show that HBI1 regulates a set of genes that largely overlaps with targets of PIFs, but displays both similar and unique transcriptional activities compared to PIFs, supporting a role in fine-tuning the network through cooperation and antagonism with other DNA-binding factors of the network. Furthermore, HBI1 also negatively regulates a subset of defense response genes. Two PAMPs, flagellin and elongation factor, repressed HBI1 expression, whereas overexpression of HBI1 reduced the PAMP-induced growth inhibition, defense gene expression, reactive oxygen species (ROS) production, and flg22-induced resistance to Pseudomonas syringae pathovar tomato DC3000. These data indicate that HBI1 is a node for crosstalk between hormone and immune pathways. This study demonstrates that the PRE-IBH1-HBI1 module integrates hormone and pathogen signals, and thus plays a central role in the balance between growth and immunity in plants. Genome wide analysis the HBI1 binding target
Project description:The trade-off between growth and immunity is crucial for survival in plants. An antagonistic interaction has been observed between the growth-promoting hormone brassinosteroid and pathogen associated molecular pattern (PAMP) signals, which induce immunity but inhibit growth, however the underlying molecular mechanism has remained unclear. The PRE-IBH1-HBI1 triple helix-loop-helix/basic helix-loop-helix (HLH/bHLH) cascade has been shown to mediate growth responses to several hormonal and environmental signals, but its downstream targets and role in immunity remain unknown. Here, we performed genome-wide analyses of HBI1 target genes in Arabidopsis. The results show that HBI1 regulates a set of genes that largely overlaps with targets of PIFs, but displays both similar and unique transcriptional activities compared to PIFs, supporting a role in fine-tuning the network through cooperation and antagonism with other DNA-binding factors of the network. Furthermore, HBI1 also negatively regulates a subset of defense response genes. Two PAMPs, flagellin and elongation factor, repressed HBI1 expression, whereas overexpression of HBI1 reduced the PAMP-induced growth inhibition, defense gene expression, reactive oxygen species (ROS) production, and flg22-induced resistance to Pseudomonas syringae pathovar tomato DC3000. These data indicate that HBI1 is a node for crosstalk between hormone and immune pathways. This study demonstrates that the PRE-IBH1-HBI1 module integrates hormone and pathogen signals, and thus plays a central role in the balance between growth and immunity in plants. Compare the transcriptome of HBI1-Ox and wild type.