scholarly journals Diversified Regulation of Cytokinin Levels and Signaling During Botrytis cinerea Infection in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Beibei Li ◽  
Ruolin Wang ◽  
Shiya Wang ◽  
Jiang Zhang ◽  
Ling Chang
Keyword(s):  
Botrytis Cinerea ◽  
Response Regulator ◽  
Plant Immunity ◽  
Defense Responses ◽  
Cytokinin Oxidase ◽  
Plant Defense Responses ◽  
Necrotrophic Pathogen ◽  
Transcriptional Changes ◽  
Complex Regulation

Cytokinins (CKs) can modulate plant immunity to various pathogens, but how CKs are involved in plant defense responses to the necrotrophic pathogen Botrytis cinerea is still unknown. Here, we found that B. cinerea infection induced transcriptional changes in multiple genes involved in the biosynthesis, degradation, and signaling of CKs, as well as their contents, in pathogen-infected Arabidopsis leaves. Among the CKs, the gene expression of CYTOKININ OXIDASE/DEHYDROGENASE 5 (CKX5) was remarkably induced in the local infected leaves and the distant leaves of the same plant without pathogen inoculation. Cis-zeatin (cZ) and its riboside (cZR) accumulated considerably in infected leaves, suggesting an important role of the cis-zeatin type of CKs in the plant response to B. cinerea. Cytokinin double-receptor mutants were more susceptible to B. cinerea infection, whereas an exogenous CK treatment enhanced the expression levels of defense-related genes and of jasmonic acid (JA) and ethylene (ET), but not salicylic acid (SA), resulting in higher resistance of Arabidopsis to B. cinerea. Investigation of CK responses to B. cinerea infection in the JA biosynthesis mutant, jar1-1, and ET-insensitive mutant, ein2-1, showed that CK signaling and levels of CKs, namely, those of isopentenyladenine (iP), isopentenyladenine riboside (iPR), and trans-zeatin (tZ), were enhanced in jar1-1-infected leaves. By contrast, reductions in iP, iPR, tZ, and tZ riboside (tZR) as well as cZR contents occurred in ein2-1-infected leaves, whose transcript levels of CK signaling genes were likewise differentially regulated. The Arabidopsis Response Regulator 5 (ARR5) gene was upregulated in infected leaves of ein2-1 whereas another type-A response regulator, ARR16, was significantly downregulated, suggesting the existence of a complex regulation of CK signaling via the ET pathway. Accumulation of the cis-zeatin type of CKs in B. cinerea-infected leaves depended on ET but not JA pathways. Collectively, our findings provide evidence that CK responds to B. cinerea infection in a variety of ways that are differently modulated by JA and ET pathways in Arabidopsis.

scholarly journals Pseudomonas fluorescens DN16 Enhances Cucumber Defense Responses Against the Necrotrophic Pathogen Botrytis cinerea by Regulating Thermospermine Catabolism

2021 ◽  
Vol 12 ◽  
Author(s):  
Lin Zhu ◽  
Nana Qian ◽  
Yujun Sun ◽  
Xiaoming Lu ◽  
Haiming Duan ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Botrytis Cinerea ◽  
Defense Responses ◽  
Pathogen Infection ◽  
Necrotrophic Pathogen ◽  
Catabolic Enzymes ◽  
Catabolic Genes ◽  
Pathogenesis Related Protein ◽  
Pathogenesis Related

Plants can naturally interact with beneficial rhizobacteria to mediate defense responses against foliar pathogen infection. However, the mechanisms of rhizobacteria-mediated defense enhancement remain rarely clear. In this study, beneficial rhizobacterial strain Pseudomonas fluorescens DN16 greatly increased the resistance of cucumber plants against Botrytis cinerea infection. RNA-sequencing analyses showed that several polyamine-associated genes including a thermospermine (TSpm) synthase gene (CsACL5) and polyamine catabolic genes (CsPAO1, CsPAO5, and CsCuAO1) were notably induced by DN16. The associations of TSpm metabolic pathways with the DN16-mediated cucumber defense responses were further investigated. The inoculated plants exhibited the increased leaf TSpm levels compared with the controls. Accordantly, overexpression of CsACL5 in cucumber plants markedly increased leaf TSpm levels and enhanced defense against B. cinerea infection. The functions of TSpm catabolism in the DN16-mediated defense responses of cucumber plants to B. cinerea were further investigated by pharmacological approaches. Upon exposure to pathogen infection, the changes of leaf TSpm levels were positively related to the enhanced activities of polyamine catabolic enzymes including polyamine oxidases (PAOs) and copper amine oxidases (CuAOs), which paralleled the transcription of several defense-related genes such as pathogenesis-related protein 1 (CsPR1) and defensin-like protein 1 (CsDLP1). However, the inhibited activities of polyamine catabolic enzymes abolished the DN16-induced cucumber defense against B. cinerea infection. This was in line with the impaired expression of defense-related genes in the inoculated plants challenged by B. cinerea. Collectively, our findings unraveled a pivotal role of TSpm catabolism in the regulation of the rhizobacteria-primed defense states by mediating the immune responses in cucumber plants after B. cinerea infection.

scholarly journals Metatranscriptomic Analysis of Multiple Environmental Stresses Identifies RAP2.4 Gene Associated with Arabidopsis Immunity to Botrytis cinerea

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Arjun Sham ◽  
Hibatullah Al-Ashram ◽  
Kenna Whitley ◽  
Rabah Iratni ◽  
Khaled A. El-Tarabily ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Plant Immunity ◽  
Interaction Network ◽  
Defense Responses ◽  
Plant Responses ◽  
Breeding Programs ◽  
Protein Protein Interaction ◽  
Genetic Components ◽  
Protein Protein Interaction Network

AbstractIn this study, we aimed to identify common genetic components during stress response responsible for crosstalk among stresses, and to determine the role of differentially expressed genes in Arabidopsis-Botrytis cinerea interaction. Of 1,554 B. cinerea up-regulated genes, 24%, 1.4% and 14% were induced by biotic, abiotic and hormonal treatments, respectively. About 18%, 2.5% and 22% of B. cinerea down-regulated genes were also repressed by the same stress groups. Our transcriptomic analysis indicates that plant responses to all tested stresses can be mediated by commonly regulated genes; and protein-protein interaction network confirms the cross-interaction between proteins regulated by these genes. Upon challenges to individual or multiple stress(es), accumulation of signaling molecules (e.g. hormones) plays a major role in the activation of downstream defense responses. In silico gene analyses enabled us to assess the involvement of RAP2.4 (related to AP2.4) in plant immunity. Arabidopsis RAP2.4 was repressed by B. cinerea, and its mutants enhanced resistance to the same pathogen. To the best of our knowledge, this is the first report demonstrating the role of RAP2.4 in plant defense against B. cinerea. This research can provide a basis for breeding programs to increase tolerance and improve yield performance in crops.

MPK3/MPK6-mediated ERF72 Phosphorylation Positively Regulates Resistance to Botrytis cinerea Through Directly and Indirectly Activating the Transcription of Camalexin-biosynthesis Enzymes

2021 ◽  
Author(s):  
Yihao Li ◽  
Kun Liu ◽  
Ganlu Tong ◽  
Chao Xi ◽  
Jin Liu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Botrytis Cinerea ◽  
Target Genes ◽  
Plant Immunity ◽  
Ethylene Response Factor ◽  
Wild Type ◽  
Abiotic Stress Response ◽  
Necrotrophic Pathogen ◽  
Ethylene Response

Abstract Ethylene response factor (ERF) Group VII members generally function in regulating plant growth and development, abiotic stress response, and plant immunity in Arabidopsis. However, the detail regulatory mechanism by which Group VII ERFs mediate plant immune responses remains elusive. Here, we characterised ERF72, a member of the Group VII ERFs, as a positive regulator mediating resistance to the necrotrophic pathogen Botrytis cinerea. Compared with wild type (WT), erf72 mutant showed the lower camalexin contents and more susceptible to B. cinerea, while complementation of ERF72 in erf72 rescued susceptibility phenotypes. Moreover, overexpression of ERF72 in WT promoted camalexin biosynthesis and resistance to B. cinerea. Then, we identified camalexin biosynthesis genes PAD3 and CYP71A13, and transcription factor WRKY33 as target genes of ERF72. Furthermore, MPK3 and MPK6 phosphorylate ERF72 at Ser151 to improve its transactivation activity, camalexin contents and resistance to B. cinerea. These findings highlight the role of ERF72 in coordinating the camalexin biosynthesis via directly regulating the expression of camalexin biosynthetic genes and indirectly by targeting WRKK33 in plant immunity.

scholarly journals Method for the Production and Purification of Plant Immuno-Active Xylanase from Trichoderma

2021 ◽  
Vol 22 (8) ◽  
pp. 4214
Author(s):  
Gautam Anand ◽  
Meirav Leibman-Markus ◽  
Dorin Elkabetz ◽  
Maya Bar
Keyword(s):  
Immune System ◽  
Plant Defense ◽  
Plant Immunity ◽  
Xylanase Activity ◽  
Hydrolytic Enzymes ◽  
Adaptive Immune System ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Xylanase Production ◽  
Ideal System

Plants lack a circulating adaptive immune system to protect themselves against pathogens. Therefore, they have evolved an innate immune system based upon complicated and efficient defense mechanisms, either constitutive or inducible. Plant defense responses are triggered by elicitors such as microbe-associated molecular patterns (MAMPs). These components are recognized by pattern recognition receptors (PRRs) which include plant cell surface receptors. Upon recognition, PRRs trigger pattern-triggered immunity (PTI). Ethylene Inducing Xylanase (EIX) is a fungal MAMP protein from the plant-growth-promoting fungi (PGPF)–Trichoderma. It elicits plant defense responses in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum), making it an excellent tool in the studies of plant immunity. Xylanases such as EIX are hydrolytic enzymes that act on xylan in hemicellulose. There are two types of xylanases: the endo-1, 4-β-xylanases that hydrolyze within the xylan structure, and the β-d-xylosidases that hydrolyze the ends of the xylan chain. Xylanases are mainly synthesized by fungi and bacteria. Filamentous fungi produce xylanases in high amounts and secrete them in liquid cultures, making them an ideal system for xylanase purification. Here, we describe a method for cost- and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate. Xylanase produced by this method possessed xylanase activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis, and ROS burst.

scholarly journals THESEUS1 positively modulates plant defense responses against Botrytis cinerea through GUANINE EXCHANGE FACTOR4 signaling

2017 ◽  
Vol 59 (11) ◽  
pp. 797-804 ◽  
Author(s):  
Shaofeng Qu ◽  
Xi Zhang ◽  
Yutong Song ◽  
Jinxing Lin ◽  
Xiaoyi Shan
Keyword(s):  
Plant Defense ◽  
Botrytis Cinerea ◽  
Defense Responses ◽  
Plant Defense Responses

scholarly journals Silicon in plant disease control

Revista CERES ◽  
2015 ◽  
Vol 62 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Edson Ampélio Pozza ◽  
Adélia Aziz Alexandre Pozza ◽  
Deila Magna dos Santos Botelho
Keyword(s):  
Disease Control ◽  
Defense Responses ◽  
Plant Diseases ◽  
Plant Cell Walls ◽  
Plant Defense Responses ◽  
Polyphenol Oxidases ◽  
Plant Disease Control ◽  
Essential Nutrient ◽  
Increased Activity

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

scholarly journals How to Unravel the Key Functions of Cryptic Oomycete Elicitin Proteins and Their Role in Plant Disease

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1201
Author(s):  
Aayushree Kharel ◽  
Md Tohidul Islam ◽  
James Rookes ◽  
David Cahill
Keyword(s):  
Gene Editing ◽  
Plant Disease ◽  
Plant Cells ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Host Pathogen Interactions ◽  
Binding Ability ◽  
Host Pathogen ◽  
Pathogen Colonization

Pathogens and plants are in a constant battle with one another, the result of which is either the restriction of pathogen growth via constitutive or induced plant defense responses or the pathogen colonization of plant cells and tissues that cause disease. Elicitins are a group of highly conserved proteins produced by certain oomycete species, and their sterol binding ability is recognized as an important feature in sterol–auxotrophic oomycetes. Elicitins also orchestrate other aspects of the interactions of oomycetes with their plant hosts. The function of elicitins as avirulence or virulence factors is controversial and is dependent on the host species, and despite several decades of research, the function of these proteins remains elusive. We summarize here our current understanding of elicitins as either defense-promoting or defense-suppressing agents and propose that more recent approaches such as the use of ‘omics’ and gene editing can be used to unravel the role of elicitins in host–pathogen interactions. A better understanding of the role of elicitins is required and deciphering their role in host–pathogen interactions will expand the strategies that can be adopted to improve disease resistance and reduce crop losses.

scholarly journals Two Arabidopsis Homologs of Human Lysine-Specific Demethylase Function in Epigenetic Regulation of Plant Defense Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Seong Woo Noh ◽  
Ri-Ra Seo ◽  
Hee Jin Park ◽  
Ho Won Jung
Keyword(s):  
Pseudomonas Syringae ◽  
Epigenetic Regulation ◽  
Plant Immunity ◽  
Systemic Disease ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Promoter Regions ◽  
Lysine Specific Demethylase ◽  
Genome Wide ◽  
Histone H3k4

Epigenetic marks such as covalent histone modification and DNA methylation are crucial for mitotically and meiotically inherited cellular memory-based plant immunity. However, the roles of individual players in the epigenetic regulation of plant immunity are not fully understood. Here we reveal the functions of two Arabidopsis thaliana homologs of human lysine-specific demethylase1-like1, LDL1 and LDL2, in the maintenance of methyl groups at lysine 4 of histone H3 and in plant immunity to Pseudomonas syringae infection. The growth of virulent P. syringae strains was reduced in ldl1 and ldl2 single mutants compared to wild-type plants. Local and systemic disease resistance responses, which coincided with the rapid, robust transcription of defense-related genes, were more stably expressed in ldl1 ldl2 double mutants than in the single mutants. At the nucleosome level, mono-methylated histone H3K4 accumulated in ldl1 ldl2 plants genome-wide and in the mainly promoter regions of the defense-related genes examined in this study. Furthermore, in silico comparative analysis of RNA-sequencing and chromatin immunoprecipitation data suggested that several WRKY transcription factors, e.g., WRKY22/40/70, might be partly responsible for the enhanced immunity of ldl1 ldl2. These findings suggest that LDL1 and LDL2 control the transcriptional sensitivity of a group of defense-related genes to establish a primed defense response in Arabidopsis.

scholarly journals Jasmonic Acid at the Crossroads of Plant Immunity and Pseudomonas syringae Virulence

2020 ◽  
Vol 21 (20) ◽  
pp. 7482
Author(s):  
Aarti Gupta ◽  
Mamta Bhardwaj ◽  
Lam-Son Phan Tran
Keyword(s):  
Jasmonic Acid ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Regulatory Networks ◽  
Genetic Manipulation ◽  
Plant Immunity ◽  
Stomatal Closure ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Callose Deposition

Sensing of pathogen infection by plants elicits early signals that are transduced to affect defense mechanisms, such as effective blockage of pathogen entry by regulation of stomatal closure, cuticle, or callose deposition, change in water potential, and resource acquisition among many others. Pathogens, on the other hand, interfere with plant physiology and protein functioning to counteract plant defense responses. In plants, hormonal homeostasis and signaling are tightly regulated; thus, the phytohormones are qualified as a major group of signaling molecules controlling the most widely tinkered regulatory networks of defense and counter-defense strategies. Notably, the phytohormone jasmonic acid mediates plant defense responses to a wide array of pathogens. In this review, we present the synopsis on the jasmonic acid metabolism and signaling, and the regulatory roles of this hormone in plant defense against the hemibiotrophic bacterial pathogen Pseudomonas syringae. We also elaborate on how this pathogen releases virulence factors and effectors to gain control over plant jasmonic acid signaling to effectively cause disease. The findings discussed in this review may lead to ideas for the development of crop cultivars with enhanced disease resistance by genetic manipulation.

scholarly journals A Role of Cytokinin Transporter in Arabidopsis Immunity

2017 ◽  
Vol 30 (4) ◽  
pp. 325-333 ◽  
Author(s):  
Shuai Wang ◽  
Shu Wang ◽  
Qi Sun ◽  
Leiyun Yang ◽  
Ying Zhu ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Induced Defense ◽  
Plant Immunity ◽  
Receptor Gene ◽  
Defense Responses ◽  
Plant Growth And Development ◽  
Immune Receptor ◽  
Receptor Mutant ◽  
Induced Defense Responses

The phytohormone cytokinin (CK) is not only essential for plant growth and development but also impacts plant immunity. A mutant screen in a constitutively active plant immune receptor mutant snc1 (suppressor of npr1, constitutive1) identified a suppressor mutation of SNC1-induced defense responses in an ABC transporter coding gene ABCG14. ABCG14 transports CK from roots to the shoots, and the suppression of the SNC1-mediated defense response by the loss of ABCG14 is due to a deficiency of trans-zeatin (tZ)-type CK in the shoot. In addition, exogenous application of the tZ-type CK enhances disease resistance associated with increased expression of the plant immune receptor gene SNC1. Taken together, this study further established the role of tZ-type CK in disease resistance and suggests a new intersection of CKs with plant immunity at the expression regulation of a plant immune receptor gene.

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