A group I WRKY transcription factor regulates mulberry mosaic dwarf‐associated virus‐triggered cell death in Nicotiana benthamiana

WRKY transcription factor genes play critical roles in plant growth and development, as well as stress responses. WRKY genes have been examined in various higher plants, but they have not been characterized inLotus japonicus. The recent release of theL. japonicuswhole genome sequence provides an opportunity for a genome wide analysis of WRKY genes in this species. In this study, we identified 61 WRKY genes in theL. japonicusgenome. Based on the WRKY protein structure,L. japonicusWRKY (LjWRKY) genes can be classified into three groups (I–III). Investigations of gene copy number and gene clusters indicate that only one gene duplication event occurred on chromosome 4 and no clustered genes were detected on chromosomes 3 or 6. Researchers previously believed that group II and III WRKY domains were derived from the C-terminal WRKY domain of group I. Our results suggest that some WRKY genes in group II originated from the N-terminal domain of group I WRKY genes. Additional evidence to support this hypothesis was obtained byMedicago truncatulaWRKY (MtWRKY) protein motif analysis. We found that LjWRKY and MtWRKY group III genes are under purifying selection, suggesting that WRKY genes will become increasingly structured and functionally conserved.

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Genome-wide identification and expression analysis of the WRKY transcription factor family in flax (Linum usitatissimum L.)

BMC Genomics ◽

10.1186/s12864-021-07697-w ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Hongmei Yuan ◽

Wendong Guo ◽

Lijuan Zhao ◽

Ying Yu ◽

Si Chen ◽

...

Keyword(s):

Transcription Factor ◽

Plant Growth ◽

Stress Responses ◽

Linum Usitatissimum ◽

Developmental Stages ◽

Lignin Content ◽

Expression Patterns ◽

Wrky Transcription Factor ◽

Group I ◽

Genome Wide

Abstract Background Members of the WRKY protein family, one of the largest transcription factor families in plants, are involved in plant growth and development, signal transduction, senescence, and stress resistance. However, little information is available about WRKY transcription factors in flax (Linum usitatissimum L.). Results In this study, comprehensive genome-wide characterization of the flax WRKY gene family was conducted that led to prediction of 102 LuWRKY genes. Based on bioinformatics-based predictions of structural and phylogenetic features of encoded LuWRKY proteins, 95 LuWRKYs were classified into three main groups (Group I, II, and III); Group II LuWRKYs were further assigned to five subgroups (IIa-e), while seven unique LuWRKYs (LuWRKYs 96–102) could not be assigned to any group. Most LuWRKY proteins within a given subgroup shared similar motif compositions, while a high degree of motif composition variability was apparent between subgroups. Using RNA-seq data, expression patterns of the 102 predicted LuWRKY genes were also investigated. Expression profiling data demonstrated that most genes associated with cellulose, hemicellulose, or lignin content were predominantly expressed in stems, roots, and less in leaves. However, most genes associated with stress responses were predominantly expressed in leaves and exhibited distinctly higher expression levels in developmental stages 1 and 8 than during other stages. Conclusions Ultimately, the present study provides a comprehensive analysis of predicted flax WRKY family genes to guide future investigations to reveal functions of LuWRKY proteins during plant growth, development, and stress responses.

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MdWRKY100 encodes a group I WRKY transcription factor in Malus domestica that positively regulates resistance to Colletotrichum gloeosporioides infection

Plant Science ◽

10.1016/j.plantsci.2019.06.001 ◽

2019 ◽

Vol 286 ◽

pp. 68-77 ◽

Cited By ~ 3

Author(s):

Feng Zhang ◽

Feng Wang ◽

Shuang Yang ◽

Yuanyan Zhang ◽

Hao Xue ◽

...

Keyword(s):

Transcription Factor ◽

Malus Domestica ◽

Colletotrichum Gloeosporioides ◽

Wrky Transcription Factor ◽

Group I

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GhWRKY44, a WRKY transcription factor of cotton, mediates defense responses to pathogen infection in transgenic Nicotiana benthamiana

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-014-0688-9 ◽

2014 ◽

Vol 121 (1) ◽

pp. 127-140 ◽

Cited By ~ 24

Author(s):

Jing Li ◽

Ji Wang ◽

Ningxin Wang ◽

Xingqi Guo ◽

Zheng Gao

Keyword(s):

Transcription Factor ◽

Nicotiana Benthamiana ◽

Defense Responses ◽

Wrky Transcription Factor ◽

Pathogen Infection

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Arabidopsis WRKY70 Is Required for Full RPP4-Mediated Disease Resistance and Basal Defense Against Hyaloperonospora parasitica

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-20-2-0120 ◽

2007 ◽

Vol 20 (2) ◽

pp. 120-128 ◽

Cited By ~ 126

Author(s):

Colleen Knoth ◽

Jon Ringler ◽

Jeffery L. Dangl ◽

Thomas Eulgem

Keyword(s):

Cell Death ◽

Transcription Factor ◽

Salicylic Acid ◽

Defense Mechanism ◽

Wrky Transcription Factor ◽

Reactive Oxygen Intermediates ◽

Oxygen Intermediates ◽

Transcript Levels ◽

Hyaloperonospora Parasitica ◽

Basal Defense

AtWRKY70, encoding a WRKY transcription factor, is co-expressed with a set of Arabidopsis genes that share a pattern of RPP4- and RPP7-dependent late upregulation in response to Hyaloperonospora parasitica infection (LURP) genes. We show that AtWRKY70 is required for both full RPP4-mediated resistance and basal defense against H. parasitica. These two defense pathways are related to each other, because they require PAD4 and salicylic acid (SA). RPP7 function, which is independent from PAD4 and SA, is not affected by insertions in AtWRKY70. Although AtWRKY70 is required for RPP4-resistance, it appears not to contribute significantly to RPP4-triggered cell death. Furthermore, our data indicate that AtWRKY70 functions downstream of defense-associated reactive oxygen intermediates and SA. Constitutive and RPP4-induced transcript levels of two other LURP genes are reduced in AtWRKY70 T-DNA mutants, indicating a direct or indirect role for AtWRKY70 in their regulation. We propose that AtWRKY70 is a component of a basal defense mechanism that is boosted by engagement of either RPP4 or RPP7 and is required for RPP4-mediated resistance.

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The Nicotiana benthamiana Mitogen-Activated Protein Kinase Cascade and WRKY Transcription Factor Participate in Nep1Mo-Triggered Plant Responses

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-11-11-0293 ◽

2012 ◽

Vol 25 (12) ◽

pp. 1639-1653 ◽

Cited By ~ 28

Author(s):

Huajian Zhang ◽

Deqing Li ◽

Meifang Wang ◽

Jiewen Liu ◽

Wenjun Teng ◽

...

Keyword(s):

Cell Death ◽

Transcription Factor ◽

Protein Kinase ◽

Immune Responses ◽

Nicotiana Benthamiana ◽

Stomatal Closure ◽

Mapk Cascade ◽

Mitogen Activated Protein Kinase ◽

Plant Responses ◽

Mitogen Activated Protein

Many bacterial, fungal, and oomycete species secrete necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLP) that trigger programmed cell death (PCD) and innate immune responses in dicotyledonous plants. However, how NLP induce such immune responses is not understood. Here, we show that silencing of the MAPKKKα–MEK2–WIPK mitogen-activated protein kinase (MAPK) cascade through virus-induced gene silencing compromises hydrogen peroxide accumulation and PCD induced by Nep1Mo from Magnaporthe oryzae. WIPK interacts with NbWRKY2, a transcription factor in Nicotiana benthamiana, in vitro and in vivo, suggesting an effector pathway that mediates Nep1Mo-induced cell death. Unexpectedly, salicylic acid–induced protein kinase (SIPK)- and NbWRKY2-silenced plants showed impaired Nep1Mo-induced stomatal closure, decreased Nep1Mo-promoted nitric oxide (NO) production in guard cells, and a reduction in Nep1Mo-induced resistance against Phytophthora nicotianae. Expression studies by real-time polymerase chain reaction suggested that the MEK2–WIPK–NbWRKY2 pathway regulated Nep1Mo-triggered NO accumulation could be partly dependent on nitrate reductase, which was implicated in NO synthesis. Taken together, these studies demonstrate that the MAPK cascade is involved in Nep1Mo-triggered plant responses and MAPK signaling associated with PCD exhibits shared and distinct components with that for stomatal closure.

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