scholarly journals Regulating the Regulators: The Control of Transcription Factors in Plant Defense Signaling

2018 ◽  
Vol 19 (12) ◽  
pp. 3737 ◽  
Author(s):  
Danny Ng ◽  
Jayami Abeysinghe ◽  
Maedeh Kamali
Keyword(s):  
Transcription Factors ◽  
Plant Defense ◽  
Signaling Pathways ◽  
Stress Responses ◽  
Crop Production ◽  
Defense Responses ◽  
Sequencing Data ◽  
Basic Leucine Zipper ◽  
Master Regulators ◽  
External Threats

Being sessile, plants rely on intricate signaling pathways to mount an efficient defense against external threats while maintaining the cost balance for growth. Transcription factors (TFs) form a repertoire of master regulators in controlling various processes of plant development and responses against external stimuli. There are about 58 families of TFs in plants and among them, six major TF families (AP2/ERF (APETALA2/ethylene responsive factor), bHLH (basic helix-loop-helix), MYB (myeloblastosis related), NAC (no apical meristem (NAM), Arabidopsis transcription activation factor (ATAF1/2), and cup-shaped cotyledon (CUC2)), WRKY, and bZIP (basic leucine zipper)) are found to be involved in biotic and abiotic stress responses. As master regulators of plant defense, the expression and activities of these TFs are subjected to various transcriptional and post-transcriptional controls, as well as post-translational modifications. Many excellent reviews have discussed the importance of these TFs families in mediating their downstream target signaling pathways in plant defense. In this review, we summarize the molecular regulatory mechanisms determining the expression and activities of these master regulators themselves, providing insights for studying their variation and regulation in crop wild relatives (CWR). With the advance of genome sequencing and the growing collection of re-sequencing data of CWR, now is the time to re-examine and discover CWR for the lost or alternative alleles of TFs. Such approach will facilitate molecular breeding and genetic improvement of domesticated crops, especially in stress tolerance and defense responses, with the aim to address the growing concern of climate change and its impact on agriculture crop production.

scholarly journals Genome-Wide Identification and Expression Analysis of the bZIP Transcription Factors in the Mycoparasite Coniothyrium minitans

2020 ◽  
Vol 8 (7) ◽  
pp. 1045
Author(s):  
Yuping Xu ◽  
Yongchun Wang ◽  
Huizhang Zhao ◽  
Mingde Wu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Abiotic Stress ◽  
Gene Family ◽  
Expression Analysis ◽  
Stress Responses ◽  
Leucine Zipper ◽  
Coniothyrium Minitans ◽  
Basic Leucine Zipper ◽  
Bzip Domain ◽  
Conidial Development

The basic leucine zipper (bZIP) proteins family is one of the largest and most diverse transcription factors, widely distributed in eukaryotes. However, no information is available regarding the bZIP gene family in Coniothyrium minitans, an important biocontrol agent of the plant pathogen Sclerotinia sclerotiorum. In this study, we identified 34 bZIP genes from the C. minitans genome, which were classified into 8 groups based on their phylogenetic relationships. Intron analysis showed that 28 CmbZIP genes harbored a variable number of introns, and 15 of them shared a feature that intron inserted into the bZIP domain. The intron position in bZIP domain was highly conserved, which was related to recognize the arginine (R) and could be treated as a genomic imprinting. Expression analysis of the CmbZIP genes in response to abiotic stresses indicated that they might play distinct roles in abiotic stress responses. Results showed that 22 CmbZIP genes were upregulated during the later stage of conidial development. Furthermore, transcriptome analysis indicated that CmbZIP genes are involved in different stages of mycoparasitism. Among deletion mutants of four CmbZIPs (CmbZIP07, -09, -13, and -16), only ΔCmbZIP16 mutants significantly reduced its tolerance to the oxidative stress. The other mutants exhibited no significant effects on colony morphology, mycelial growth, conidiation, and mycoparasitism. Taken together, our results suggested that CmbZIP genes play important roles in the abiotic stress responses, conidial development, and mycoparasitism. These results provide comprehensive information of the CmbZIP gene family and lay the foundation for further research on the bZIP gene family regarding their biological functions and evolutionary history.

scholarly journals Reprogramming and remodeling: transcriptional and epigenetic regulation of salicylic acid-mediated plant defense

2020 ◽  
Vol 71 (17) ◽  
pp. 5256-5268 ◽  
Author(s):  
Jian Chen ◽  
Michael Clinton ◽  
Guang Qi ◽  
Daowen Wang ◽  
Fengquan Liu ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Transcription Factors ◽  
Plant Defense ◽  
Epigenetic Regulation ◽  
Current Knowledge ◽  
Plant Immunity ◽  
Defense Responses ◽  
Transcriptional Networks ◽  
Transcriptional Reprogramming ◽  
Genomic Tools

Abstract As a plant hormone, salicylic acid (SA) plays essential roles in plant defense against biotrophic and hemibiotrophic pathogens. Significant progress has been made in understanding the SA biosynthesis pathways and SA-mediated defense signaling networks in the past two decades. Plant defense responses involve rapid and massive transcriptional reprogramming upon the recognition of pathogens. Plant transcription factors and their co-regulators are critical players in establishing a transcription regulatory network and boosting plant immunity. A multitude of transcription factors and epigenetic regulators have been discovered, and their roles in SA-mediated defense responses have been reported. However, our understanding of plant transcriptional networks is still limited. As such, novel genomic tools and bioinformatic techniques will be necessary if we are to fully understand the mechanisms behind plant immunity. Here, we discuss current knowledge, provide an update on the SA biosynthesis pathway, and describe the transcriptional and epigenetic regulation of SA-mediated plant immune responses.

Witches’ broom disease of lime contributes to phytoplasma epidemics and attracts insect vectors

Plant Disease ◽  
2020 ◽  
Author(s):  
Ali Masoud Al-Subhi ◽  
Abdullah Mohammed Al-Sadi ◽  
Rashid Al-Yahyai ◽  
Yazhou Chen ◽  
Thomas Mathers ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Plant Defense ◽  
Defense Responses ◽  
Insect Vectors ◽  
Plant Defense Responses ◽  
Gene Encoding ◽  
Axillary Branching ◽  
Broom Disease ◽  
Acid Lime ◽  
Lime Production

An insect-transmitted phytoplasma causing Witches’ Broom Disease of Lime (WBDL) is responsible for the drastic decline in lime production in several countries. However, it is unclear how WBDL phytoplasma (WBDLp) induces witches’ broom symptoms and if these symptoms contribute to the spread of phytoplasma. Here we show that the gene encoding SAP11 of WBDLp (SAP11WBDL) is present in all WBDLp isolates collected from diseased trees. SAP11WBDL interacts with acid lime (Citrus aurantifolia) TCP transcription factors, specifically members of the TB1/CYC class that have a role in suppressing axillary branching in plants. Sampling of WBDLp-infected lime trees revealed that WBDLp titers and SAP11WBDL expression levels were higher in symptomatic leaves compared to asymptomatic sections of the same trees. Moreover, the witches’ brooms were found to attract the vector leafhopper. Defense genes that have a role in plant defense responses to bacteria and insects are more downregulated in witches’ brooms compared to asymptomatic sections of trees. These findings suggest that witches’ broom-affected parts of the trees contribute to WBDL epidemics by supporting higher phytoplasma titers and attracting insect vectors.

scholarly journals Genome-wide characterization and evolutionary analysis of heat stress transcription factors (HSFs) to reveal their potential role under abiotic stresses in radish (Raphanus sativus L.)

2019 ◽  
Author(s):  
Mingjia Tang ◽  
Liang Xu ◽  
Yan Wang ◽  
Wanwan Cheng ◽  
Xiaobo Luo ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Abiotic Stress ◽  
Stress Responses ◽  
Abiotic Stresses ◽  
Raphanus Sativus ◽  
Crop Production ◽  
Expression Patterns ◽  
Protein Domain ◽  
Evolutionary Analysis ◽  
Raphanus Sativus L

Abstract Background Abiotic stresses due to climate change pose a great threat to crop production. Heat shock transcription factors (HSFs) are vital regulators that play key roles in protecting plants against various abiotic stresses. Therefore, the identification and characterization of HSFs is imperative to dissect the mechanism responsible for plant stress responses. Although the HSF gene family has been extensively studied in several plant species, its characterization, evolutionary history and expression patterns in the radish (Raphanus sativus L.) remain limited. Results In this study, 33 RsHSF genes were obtained from the radish genome, which were classified into three main groups and 12 subgroups based on HSF protein domain structure. Chromosomal localization analysis revealed that 28 of 33 RsHSF genes were located on nine chromosomes, and 10 duplicated RsHSF genes were grouped into eight gene pairs by whole genome duplication (WGD). Moreover, there were 23 or 9 pairs of orthologous HSFs were identified between radish and Arabidopsis or rice, respectively. Comparative analysis revealed a close relationship among radish, Chinese cabbage and Arabidopsis. RNA-seq data showed that eight RsHSF genes, including RsHSF-03, were highly expressed in the leaf, root, cortex, cambium and xylem, results that these genes might be involved in plant growth and development. Further, quantitative real-time polymerase chain reaction (RT-qPCR) indicated that the expression patterns of 12 RsHSF genes varied upon exposure to different abiotic stresses, including heat, salt, and heavy metals. This data indicated that the RsHSFs may be involved in abiotic stress response. Conclusions These results could provide fundamental insights into the characteristics and evolution of the HSF family and facilitate further dissection of the molecular mechanism responsible for radish abiotic stress responses.

scholarly journals Crosstalk between heterotrimeric G protein-coupled signaling pathways and WRKY transcription factors modulating plant responses to suboptimal micronutrient conditions

2020 ◽  
Vol 71 (10) ◽  
pp. 3227-3239
Author(s):  
Ting-Ying Wu ◽  
Shalini Krishnamoorthi ◽  
Honzhen Goh ◽  
Richalynn Leong ◽  
Amy Catherine Sanson ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Stress Tolerance ◽  
Signaling Pathways ◽  
G Protein ◽  
Stress Responses ◽  
Metal Ion ◽  
Metal Transporters ◽  
Zinc Stress ◽  
Transcriptomic Data ◽  
G Protein Coupled

Abstract Nutrient stresses induce foliar chlorosis and growth defects. Here we propose heterotrimeric G proteins as signaling mediators of various nutrient stresses, through meta-analyses of >20 transcriptomic data sets associated with nutrient stresses or G protein mutations. Systematic comparison of transcriptomic data yielded 104 genes regulated by G protein subunits under common nutrient stresses: 69 genes under Gβ subunit (AGB1) control and 35 genes under Gα subunit (GPA1) control. Quantitative real-time PCR experiments validate that several transcription factors and metal transporters changed in expression level under suboptimal iron, zinc, and/or copper concentrations, while being misregulated in the Arabidopsis Gβ-null (agb1) mutant. The agb1 mutant had altered metal ion profiles and exhibited severe growth arrest under zinc stress, and aberrant root waving under iron and zinc stresses, while the Gα-null mutation attenuated leaf chlorosis under iron deficiency in both Arabidopsis and rice. Our transcriptional network analysis inferred computationally that WRKY-family transcription factors mediate the AGB1-dependent nutrient responses. As corroborating evidence of our inference, ectopic expression of WRKY25 or WRKY33 rescued the zinc stress phenotypes and the expression of zinc transporters in the agb1-2 background. These results, together with Gene Ontology analyses, suggest two contrasting roles for G protein-coupled signaling pathways in micronutrient stress responses: one enhancing general stress tolerance and the other modulating ion homeostasis through WRKY transcriptional regulatory networks. In addition, tolerance to iron stress in the rice Gα mutant provides an inroad to improve nutrient stress tolerance of agricultural crops by manipulating G protein signaling.

scholarly journals Patterns of Drought Response of 38 WRKY Transcription Factors of Zanthoxylum bungeanum Maxim.

2018 ◽  
Vol 20 (1) ◽  
pp. 68 ◽  
Author(s):  
Xitong Fei ◽  
Lixiu Hou ◽  
Jingwei Shi ◽  
Tuxi Yang ◽  
Yulin Liu ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Signaling Pathways ◽  
Structural Characteristics ◽  
Mitogen Activated Protein Kinase ◽  
Ethylene Synthesis ◽  
Sequencing Data ◽  
Wrky Transcription Factors ◽  
Bioinformatics Analyses ◽  
Zanthoxylum Bungeanum

The WRKY family of transcription factors (TFs) includes a number of transcription-specific groupings that play important roles in plant growth and development and in plant responses to various stresses. To screen for WRKY transcription factors associated with drought stress in Zanthoxylum bungeanum, a total of 38 ZbWRKY were identified and these were then classified and identified with Arabidopsis WRKY. Using bioinformatics analyses based on the structural characteristics of the conservative domain, 38 WRKY transcription factors were identified and categorized into three groups: Groups I, II, and III. Of these, Group II can be divided into four subgroups: subgroups IIb, IIc, IId, and IIe. No ZbWRKY members of subgroup IIa were found in the sequencing data. In addition, 38 ZbWRKY were identified by real-time PCR to determine the behavior of this family of genes under drought stress. Twelve ZbWRKY transcription factors were found to be significantly upregulated under drought stress and these were identified by relative quantification. As predicted by the STRING website, the results show that the WRKYs are involved in four signaling pathways—the jasmonic acid (JA), the salicylic acid (SA), the mitogen-activated protein kinase (MAPK), and the ethylene signaling pathways. ZbWRKY33 is the most intense transcription factor in response to drought stress. We predict that WRKY33 binds directly to the ethylene synthesis precursor gene ACS6, to promote ethylene synthesis. Ethylene then binds to the ethylene activator release signal to activate a series of downstream genes for cold stress and osmotic responses. The roles of ZbWRKY transcription factors in drought stress rely on a regulatory network center on the JA signaling pathway.

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