title: Synchronization of developmental processes and defense signaling by growth regulating transcription factors.
abstract: Growth regulating factors (GRFs) are a conserved class of transcription factor in seed plants. GRFs are involved in various aspects of tissue differentiation and organ development. The implication of GRFs in biotic stress response has also been recently reported, suggesting a role of these transcription factors in coordinating the interaction between developmental processes and defense dynamics. However, the molecular mechanisms by which GRFs mediate the overlaps between defense signaling and developmental pathways are elusive. Here, we report large scale identification of putative target candidates of Arabidopsis GRF1 and GRF3 by comparing mRNA profiles of the grf1/grf2/grf3 triple mutant and those of the transgenic plants overexpressing miR396-resistant version of GRF1 or GRF3. We identified 1,098 and 600 genes as putative targets of GRF1 and GRF3, respectively. Functional classification of the potential target candidates revealed that GRF1 and GRF3 contribute to the regulation of various biological processes associated with defense response and disease resistance. GRF1 and GRF3 participate specifically in the regulation of defense-related transcription factors, cell-wall modifications, cytokinin biosynthesis and signaling, and secondary metabolites accumulation. GRF1 and GRF3 seem to fine-tune the crosstalk between miRNA signaling networks by regulating the expression of several miRNA target genes. In addition, our data suggest that GRF1 and GRF3 may function as negative regulators of gene expression through their association with other transcription factors. Collectively, our data provide new insights into how GRF1 and GRF3 might coordinate the interactions between defense signaling and plant growth and developmental pathways.
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Jinyi
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: J Hollis
authors.initials: JH
authors.lastname: Rice
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Nana
authors.initials: N
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Baum
authors.affiliation: Department of Plant Sciences, University of Tennessee, Knoxville, Tennessee, United States of America.
authors.forename: Tarek
authors.initials: T
authors.lastname: Hewezi
mesh_terms: D000220:Adaptation, Biological; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins; D002135:Calcium-Binding Proteins; D016000:Cluster Analysis; D016207:Cytokines / Q000378:metabolism; D060467:Disease Resistance; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006728:Hormones / Q000096:biosynthesis; D035683:MicroRNAs / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020666:ras-GRF1
chemical_list: D029681:Arabidopsis Proteins; D002135:Calcium-Binding Proteins; D016207:Cytokines; C087620:GF14 protein, Arabidopsis; D006728:Hormones; D035683:MicroRNAs; D014157:Transcription Factors; D020666:ras-GRF1