scholarly journals Salicylic Acid and NPR1 Induce the Recruitment of trans-Activating TGA Factors to a Defense Gene Promoter in Arabidopsis

2003 ◽  
Vol 15 (8) ◽  
pp. 1846-1858 ◽  
Author(s):  
Christopher Johnson ◽  
Erin Boden ◽  
Jonathan Arias
Keyword(s):  
Salicylic Acid ◽  
Gene Promoter ◽  
Defense Gene ◽  
Tga Factors

Plant Defense Gene Promoter-Reporter Gene Fusions in Transgenic Plants: Tools for Identification of Novel Inducers

1990 ◽  
Vol 8 (9) ◽  
pp. 845-848 ◽  
Author(s):  
Peter W. Doerner ◽  
Bruce Stermer ◽  
Jürg Schmid ◽  
Richard A. Dixon ◽  
Christopher J. Lamb
Keyword(s):  
Transgenic Plants ◽  
Plant Defense ◽  
Reporter Gene ◽  
Gene Promoter ◽  
Gene Fusions ◽  
Defense Gene

NPR1 enhances the DNA binding activity of the Arabidopsis bZIP transcription factor TGA7This paper is one of a selection of papers published in a Special Issue from the National Research Council of Canada – Plant Biotechnology Institute.

Botany ◽  
2009 ◽  
Vol 87 (6) ◽  
pp. 561-570 ◽  
Author(s):  
Heather L. Shearer ◽  
Lipu Wang ◽  
Catherine DeLong ◽  
Charles Despres ◽  
Pierre R. Fobert
Keyword(s):  
Salicylic Acid ◽  
Dna Binding ◽  
National Research Council ◽  
Plant Biotechnology ◽  
Plant Genome ◽  
Bzip Transcription Factor ◽  
Resistance Mutations ◽  
Promoter Elements ◽  
Tga Factors

Pathogen-induced transcriptional reprogramming of the plant genome is mediated predominantly by the cofactor NPR1 (NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1). NPR1 lacks any known DNA-binding domain and is proposed to regulate transcription through interactions with TGA transcription factors that bind to as-1-like promoter elements. Previous studies have focused on the interaction of NPR1 with subgroup I (TGA1, TGA4) or subgroup II (TGA2, TGA5, TGA6) factors. Using the yeast two-hybrid system, we showed that a member of subgroup III (TGA7) interacts with wild-type NPR1 but not with mutants in the ankyrin repeats that are important for disease resistance. Mutations in the NPR1 BTB/POZ domain also greatly reduced interaction with TGA7. NPR1 substantially increased the binding of TGA7 to cognate promoter elements in vitro, including a salicylic-acid-inducible element of the PR-1 promoter. While TGA7 interacted with all TGA factors tested, interactions were not observed between TGA2 and subgroup I factors, indicating that cross-clade interaction is not a general property of the family. Transcripts from subgroup III TGA factors were weakly inducible by salicylic acid and pathogens, but only TGA3 expression was dependent on NPR1. These results suggest that NPR1-mediated DNA binding of TGA7 could regulate the activation of defense genes.

scholarly journals Increased Resistance Against Citrus Canker Mediated by a Citrus Mitogen-Activated Protein Kinase

2013 ◽  
Vol 26 (10) ◽  
pp. 1190-1199 ◽  
Author(s):  
Maria Luiza Peixoto de Oliveira ◽  
Caio Cesar de Lima Silva ◽  
Valéria Yukari Abe ◽  
Marcio Gilberto Cardoso Costa ◽  
Raúl Andrés Cernadas ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Sweet Orange ◽  
Plant Immunity ◽  
Gene Promoter ◽  
Citrus Canker ◽  
Hypersensitive Reaction ◽  
Mitogen Activated Protein Kinase ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Mitogen Activated Protein

Mitogen-activated protein kinases (MAPK) play crucial roles in plant immunity. We previously identified a citrus MAPK (CsMAPK1) as a differentially expressed protein in response to infection by Xanthomonas aurantifolii, a bacterium that causes citrus canker in Mexican lime but a hypersensitive reaction in sweet oranges. Here, we confirm that, in sweet orange, CsMAPK1 is rapidly and preferentially induced by X. aurantifolii relative to Xanthomonas citri. To investigate the role of CsMAPK1 in citrus canker resistance, we expressed CsMAPK1 in citrus plants under the control of the PR5 gene promoter, which is induced by Xanthomonas infection and wounding. Increased expression of CsMAPK1 correlated with a reduction in canker symptoms and a decrease in bacterial growth. Canker lesions in plants with higher CsMAPK1 levels were smaller and showed fewer signs of epidermal rupture. Transgenic plants also revealed higher transcript levels of defense-related genes and a significant accumulation of hydrogen peroxide in response to wounding or X. citri infection. Accordingly, nontransgenic sweet orange leaves accumulate both CsMAPK1 and hydrogen peroxide in response to X. aurantifolii but not X. citri infection. These data, thus, indicate that CsMAPK1 functions in the citrus canker defense response by inducing defense gene expression and reactive oxygen species accumulation during infection.

scholarly journals Cytokinins Act Synergistically with Salicylic Acid to Activate Defense Gene Expression in Rice

2013 ◽  
Vol 26 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Chang-Jie Jiang ◽  
Masaki Shimono ◽  
Shoji Sugano ◽  
Mikiko Kojima ◽  
Xinqiong Liu ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Histochemical Staining ◽  
Rice Seedlings ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Glucuronidase Activity ◽  
Blast Fungus ◽  
Pathogenesis Related ◽  
Isopentenyl Adenine ◽  
Plant Pathogen Interactions

Hormone crosstalk is pivotal in plant–pathogen interactions. Here, we report on the accumulation of cytokinins (CK) in rice seedlings after infection of blast fungus Magnaporthe oryzae and its potential significance in rice–M. oryzae interaction. Blast infection to rice seedlings increased levels of N6-(Δ2-isopentenyl) adenine (iP), iP riboside (iPR), and iPR 5′-phosphates (iPRP) in leaf blades. Consistent with this, CK signaling was activated around the infection sites, as shown by histochemical staining for β-glucuronidase activity driven by a CK-responsive OsRR6 promoter. Diverse CK species were also detected in the hyphae (mycelium), conidia, and culture filtrates of blast fungus, indicating that M. oryzae is capable of production as well as hyphal secretion of CK. Co-treatment of leaf blades with CK and salicylic acid (SA), but not with either one alone, markedly induced pathogenesis-related genes OsPR1b and probenazole-induced protein 1 (PBZ1). These effects were diminished by RNAi-knockdown of OsNPR1 or WRKY45, the key regulators of the SA signaling pathway in rice, indicating that the effects of CK depend on these two regulators. Taken together, our data imply a coevolutionary rice–M. oryzae interaction, wherein M. oryzae probably elevates rice CK levels for its own benefits such as nutrient translocation. Rice plants, on the other hand, sense it as an infection signal and activate defense reactions through the synergistic action with SA.

scholarly journals Tobacco TGA7 mediates gene expression dependent and independent of salicylic acid

2018 ◽  
Author(s):  
Vlatka Stos-Zweifel ◽  
David Neeley ◽  
Evelyn Konopka ◽  
Meike Meissner ◽  
Meike Hermann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Leucine Zipper ◽  
Gene Activation ◽  
Chimeric Protein ◽  
Leaf Tissue ◽  
Terminal Region ◽  
Family Control ◽  
Transcription Activity ◽  
Tga Factors

ABSTRACTBasic region leucine zipper (bZIP) transcription factors of the TGA family control gene expression in response to diverse stimuli. Arabidopsis clade II and clade III TGA factors mediate salicylic acid (SA)-induced expression of PATHOGENESIS-RELATED GENE1 (PR-1) via interplay with NONEXPRESSOR OF PR GENES1 (NPR1, a.k.a. NIM1). Interaction with TGA factors occurs through the central ankyrin repeat domain of NPR1. In a yeast two-hybrid screen with the NPR1 bait, we identified TGA7, a novel member of the tobacco (Nt) TGA family grouping to clade III. TGA7 is most similar to NtTGA1a, and, like NtTGA1a, TGA7 displays transcription activity in yeast. Unexpectedly, TGA7 preferentially and uniquely interacts with the SA-sensitive C-terminal region of NtNPR1, demonstrating that NtNPR1 harbors multiple distinct TGA factor binding sites. Interaction with NPR1 impairs TGA7 transcription activity in yeast. Furthermore, TGA7 binding to the NtNPR1 C-terminus is outcompeted by SA-induced type 2 NIM1-INTERACTING (NIMIN) proteins. In tobacco plants, a TGA7–Gal4 DNA-binding domain chimeric protein (TGA7GBD) mediates SA-responsive reporter gene expression in young leaf tissue and spontaneous reporter activation in older leaves displaying PR-1 gene expression. Astonishingly, TGA7GBD is also able to activate the reporter independent from PR-1 gene expression in noninduced cotyledons of tobacco seedlings. Together, our findings support a model in which TGA7 mediates both SA-dependent and SA-independent gene activation controlled by the plant’s developmental stage and by the C-terminal region of constitutively accumulating NtNPR1.

scholarly journals Glutathione and fungal elicitor regulation of a plant defense gene promoter in electroporated protoplasts

1988 ◽  
Vol 85 (18) ◽  
pp. 6738-6742 ◽  
Author(s):  
M. Dron ◽  
S. D. Clouse ◽  
R. A. Dixon ◽  
M. A. Lawton ◽  
C. J. Lamb
Keyword(s):  
Plant Defense ◽  
Gene Promoter ◽  
Fungal Elicitor ◽  
Defense Gene

ArabidopsisGH3-LIKE DEFENSE GENE 1is required for accumulation of salicylic acid, activation of defense responses and resistance toPseudomonas syringae

2007 ◽  
Vol 51 (2) ◽  
pp. 234-246 ◽  
Author(s):  
Guru Jagadeeswaran ◽  
Surabhi Raina ◽  
Biswa R. Acharya ◽  
Shahina B. Maqbool ◽  
Stephen L. Mosher ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Defense Responses ◽  
Acid Activation ◽  
Defense Gene
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