scholarly journals Jasmonates: biosynthesis, perception and signal transduction

2020 ◽  
Vol 64 (3) ◽  
pp. 501-512
Author(s):  
Gareth Griffiths
Keyword(s):  
Stress Responses ◽  
Biotic Stress ◽  
Acyl Chain ◽  
Active Form ◽  
Control Plant ◽  
26S Proteasome ◽  
Plant Responses ◽  
Signalling Molecules ◽  
Jaz Proteins ◽  
Wide Range

Abstract Jasmonates (JAs) are physiologically important molecules involved in a wide range of plant responses from growth, flowering, senescence to defence against abiotic and biotic stress. They are rapidly synthesised from α-linolenic acid (ALA; C18:3 ∆9,12,15) by a process of oxidation, cyclisation and acyl chain shortening involving co-operation between the chloroplast and peroxisome. The active form of JA is the isoleucine conjugate, JA-isoleucine (JA-Ile), which is synthesised in the cytoplasm. Other active metabolites of JA include the airborne signalling molecules, methyl JA (Me-JA) and cis-jasmone (CJ), which act as inter-plant signalling molecules activating defensive genes encoding proteins and secondary compounds such as anthocyanins and alkaloids. One of the key defensive metabolites in many plants is a protease inhibitor that inactivates the protein digestive capabilities of insects, thereby, reducing their growth. The receptor for JA-Ile is a ubiquitin ligase termed as SCFCoi1 that targets the repressor protein JA Zim domain (JAZ) for degradation in the 26S proteasome. Removal of JAZ allows other transcription factors (TFs) to activate the JA response. The levels of JA-Ile are controlled through catabolism by hydroxylating enzymes of the cytochrome P450 (CYP) family. The JAZ proteins act as metabolic hubs and play key roles in cross-talk with other phytohormone signalling pathways in co-ordinating genome-wide responses. Specific subsets of JAZ proteins are involved in regulating different response outcomes such as growth inhibition versus biotic stress responses. Understanding the molecular circuits that control plant responses to pests and pathogens is a necessary pre-requisite to engineering plants with enhanced resilience to biotic challenges for improved agricultural yields.

Novel players fine-tune plant trade-offs

2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano
Keyword(s):  
Ubiquitin Ligase ◽  
Feedback Loop ◽  
Molecular Level ◽  
26S Proteasome ◽  
Signalling Molecules ◽  
Transcriptional Reprogramming ◽  
Trade Offs ◽  
Jaz Proteins ◽  
Regulatory Feedback Loop ◽  
Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

scholarly journals Jasmonic Acid-dependent MYC Transcription Factors Bind to a Tandem G-box Motif in the YUCCA8 and YUCCA9 Promoters to Regulate Biotic Stress Responses

2021 ◽  
Author(s):  
Marta-Marina Pérez-Alonso ◽  
Betriz Sánchez-Parra ◽  
Paloma Ortiz-García ◽  
Estrella Santamaría ◽  
Isabel Díaz ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Jasmonic Acid ◽  
Stress Responses ◽  
Pyruvic Acid ◽  
Biotic Stress ◽  
De Novo ◽  
Higher Plants ◽  
Plant Responses ◽  
Mechanical Wounding ◽  
Promoter Regions

The indole-3-pyruvic acid pathway is the major route for auxin biosynthesis in higher plants. Tryptophan aminotransferases (TAA1/TAR) and members of the YUCCA family of flavin-containing monooxygenases catalyze the conversion of L-tryptophan via indole-3-pyruvic acid into indole-3-acetic acid (IAA). It has been described that locally produced jasmonic acid (JA) in response to mechanical wounding, triggers de novo-formation of IAA through the induction of two YUCCA genes, YUC8 and YUC9. Here, we report the direct involvement of a small number of basic helix-loop-helix transcription factors of the MYC family in this process. We show that the JA-mediated regulation of YUC8 and YUC9 gene expression depends on the abundance of MYC2, MYC3, and MYC4. In support of this observation, seedlings of myc knockout mutants displayed a strongly reduced response to JA-mediated IAA formation. In addition, transactivation assays provided experimental evidence for the binding of the MYC transcription factors to a particular tandem G-box motif abundant in the promoter regions of YUC8 and YUC9, but not in those of the other YUCCA genes. Moreover, we clearly demonstrate that YUC8ox and YUC9ox overexpressing plants show less damage after spider mite infestation, thereby underlining a role of auxin in plant responses toward biotic stress cues.

scholarly journals Transcription Factors Associated with Abiotic and Biotic Stress Tolerance and Their Potential for Crops Improvement

Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 771 ◽  
Author(s):  
Baillo ◽  
Kimotho ◽  
Zhang ◽  
Xu
Keyword(s):  
Transcription Factors ◽  
Stress Tolerance ◽  
Stress Responses ◽  
Biotic Stress ◽  
Crop Improvement ◽  
Abiotic And Biotic Stress ◽  
Crop Species ◽  
Biotic Stresses ◽  
Wide Range ◽  
Tf Gene

In field conditions, crops are adversely affected by a wide range of abiotic stresses including drought, cold, salt, and heat, as well as biotic stresses including pests and pathogens. These stresses can have a marked effect on crop yield. The present and future effects of climate change necessitate the improvement of crop stress tolerance. Plants have evolved sophisticated stress response strategies, and genes that encode transcription factors (TFs) that are master regulators of stress-responsive genes are excellent candidates for crop improvement. Related examples in recent studies include TF gene modulation and overexpression approaches in crop species to enhance stress tolerance. However, much remains to be discovered about the diverse plant TFs. Of the >80 TF families, only a few, such as NAC, MYB, WRKY, bZIP, and ERF/DREB, with vital roles in abiotic and biotic stress responses have been intensively studied. Moreover, although significant progress has been made in deciphering the roles of TFs in important cereal crops, fewer TF genes have been elucidated in sorghum. As a model drought-tolerant crop, sorghum research warrants further focus. This review summarizes recent progress on major TF families associated with abiotic and biotic stress tolerance and their potential for crop improvement, particularly in sorghum. Other TF families and non-coding RNAs that regulate gene expression are discussed briefly. Despite the emphasis on sorghum, numerous examples from wheat, rice, maize, and barley are included. Collectively, the aim of this review is to illustrate the potential application of TF genes for stress tolerance improvement and the engineering of resistant crops, with an emphasis on sorghum.

scholarly journals COST1 regulates autophagy to control plant drought tolerance

2020 ◽  
Vol 117 (13) ◽  
pp. 7482-7493 ◽  
Author(s):  
Yan Bao ◽  
Wei-Meng Song ◽  
Peipei Wang ◽  
Xiang Yu ◽  
Bei Li ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Plant Growth ◽  
Drought Resistance ◽  
Stress Responses ◽  
Control Plant ◽  
26S Proteasome ◽  
Specific Gene ◽  
Physical Interaction ◽  
Autophagy Pathway ◽  
Direct Regulation

Plants balance their competing requirements for growth and stress tolerance via a sophisticated regulatory circuitry that controls responses to the external environments. We have identified a plant-specific gene, COST1 (constitutively stressed 1), that is required for normal plant growth but negatively regulates drought resistance by influencing the autophagy pathway. An Arabidopsis thaliana cost1 mutant has decreased growth and increased drought tolerance, together with constitutive autophagy and increased expression of drought-response genes, while overexpression of COST1 confers drought hypersensitivity and reduced autophagy. The COST1 protein is degraded upon plant dehydration, and this degradation is reduced upon treatment with inhibitors of the 26S proteasome or autophagy pathways. The drought resistance of a cost1 mutant is dependent on an active autophagy pathway, but independent of other known drought signaling pathways, indicating that COST1 acts through regulation of autophagy. In addition, COST1 colocalizes to autophagosomes with the autophagosome marker ATG8e and the autophagy adaptor NBR1, and affects the level of ATG8e protein through physical interaction with ATG8e, indicating a pivotal role in direct regulation of autophagy. We propose a model in which COST1 represses autophagy under optimal conditions, thus allowing plant growth. Under drought, COST1 is degraded, enabling activation of autophagy and suppression of growth to enhance drought tolerance. Our research places COST1 as an important regulator controlling the balance between growth and stress responses via the direct regulation of autophagy.

CDF transcription factors: plant regulators to deal with extreme environmental conditions

2020 ◽  
Vol 71 (13) ◽  
pp. 3803-3815 ◽  
Author(s):  
Begoña Renau-Morata ◽  
Laura Carrillo ◽  
Jose Dominguez-Figueroa ◽  
Jesús Vicente-Carbajosa ◽  
Rosa V Molina ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Plant Species ◽  
Stress Responses ◽  
Environmental Conditions ◽  
Functional Characterization ◽  
Plant Responses ◽  
Large Set ◽  
Cell Integrity ◽  
Wide Range ◽  
Adverse Environmental Conditions

Abstract In terrestrial environments, water and nutrient availabilities and temperature conditions are highly variable, and especially in extreme environments limit survival, growth, and reproduction of plants. To sustain growth and maintain cell integrity under unfavourable environmental conditions, plants have developed a variety of biochemical and physiological mechanisms, orchestrated by a large set of stress-responsive genes and a complex network of transcription factors. Recently, cycling DOF factors (CDFs), a group of plant-specific transcription factors (TFs), were identified as components of the transcriptional regulatory networks involved in the control of abiotic stress responses. The majority of the members of this TF family are activated in response to a wide range of adverse environmental conditions in different plant species. CDFs regulate different aspects of plant growth and development such as photoperiodic flowering-time control and root and shoot growth. While most of the functional characterization of CDFs has been reported in Arabidopsis, recent data suggest that their diverse roles extend to other plant species. In this review, we integrate information related to structure and functions of CDFs in plants, with special emphasis on their role in plant responses to adverse environmental conditions.

scholarly journals The light and dark sides of nitric oxide: multifaceted roles of nitric oxide in plant responses to light

2020 ◽  
Author(s):  
Patrícia Juliana Lopes-Oliveira ◽  
Halley Caixeta Oliveira ◽  
Zsuzsanna Kolbert ◽  
Luciano Freschi
Keyword(s):  
Nitric Oxide ◽  
Stress Responses ◽  
Light Stress ◽  
Control Plant ◽  
Ultraviolet B ◽  
Signaling Cascades ◽  
Carbon Gain ◽  
Plant Responses ◽  
No Production ◽  
Action Mechanisms

Abstract Light drives photosynthesis and informs plants about their surroundings. Regarded as a multifunctional signaling molecule in plants, nitric oxide (NO) has been repeatedly demonstrated to interact with light signaling cascades to control plant growth, development and metabolism. During early plant development, light-triggered NO accumulation counteracts negative regulators of photomorphogenesis and modulates the abundance of, and sensitivity to, plant hormones to promote seed germination and de-etiolation. In photosynthetically active tissues, NO is generated at distinct rates under light or dark conditions and acts at multiple target sites within chloroplasts to regulate photosynthetic reactions. Moreover, changes in NO concentrations in response to light stress promote plant defenses against oxidative stress under high light or ultraviolet-B radiation. Here we review the literature on the interaction of NO with the complicated light and hormonal signaling cascades controlling plant photomorphogenesis and light stress responses, focusing on the recently identified molecular partners and action mechanisms of NO in these events. We also discuss the versatile role of NO in regulating both photosynthesis and light-dependent stomatal movements, two key determinants of plant carbon gain. The regulation of nitrate reductase (NR) by light is highlighted as vital to adjust NO production in plants living under natural light conditions.

scholarly journals A Plant Stress-Responsive Bioreporter Coupled With Transcriptomic Analysis Allows Rapid Screening for Biocontrols of Necrotrophic Fungal Pathogens

2021 ◽  
Vol 8 ◽  
Author(s):  
Katharina Belt ◽  
Rhonda C. Foley ◽  
Cathryn A. O’Sullivan ◽  
Margaret M. Roper ◽  
Karam B. Singh ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Stress Responses ◽  
Biotic Stress ◽  
Fungal Pathogens ◽  
Transcriptomic Analysis ◽  
Biocontrol Agents ◽  
Rapid Screening ◽  
Auxin Signaling ◽  
Microbial Culture ◽  
Wide Range

Streptomyces are soil-borne Actinobacteria known to produce a wide range of enzymes, phytohormones, and metabolites including antifungal compounds, making these microbes fitting for use as biocontrol agents in agriculture. In this study, a plant reporter gene construct comprising the biotic stress-responsive glutathione S-transferase promoter GSTF7 linked to a luciferase output (GSTF7:luc) was used to screen a collection of Actinobacteria candidates for manipulation of plant biotic stress responses and their potential as biocontrol agents. We identified a Streptomyces isolate (KB001) as a strong candidate and demonstrated successful protection against two necrotrophic fungal pathogens, Sclerotinia sclerotiorum and Rhizoctonia solani, but not against a bacterial pathogen (Pseudomonas syringe). Treatment of Arabidopsis plants with either KB001 microbial culture or its secreted compounds induced a range of stress and defense response-related genes like pathogenesis-related (PR) and hormone signaling pathways. Global transcriptomic analysis showed that both treatments shared highly induced expression of reactive oxygen species and auxin signaling pathways at 6 and 24 h posttreatment, while some other responses were treatment specific. This study demonstrates that GSTF7 is a suitable marker for the rapid and preliminary screening of beneficial bacteria and selection of candidates with potential for application as biocontrols in agriculture, including the Streptomyces KB001 that was characterized here, and could provide protection against necrotrophic fungal pathogens.

RNA silencing pathways in plant development and defense

2021 ◽  
Author(s):  
Nikoleta Kryovrysanaki ◽  
Anthony James ◽  
Martha Tselika ◽  
Eirini Bardani ◽  
Kriton Kalantidis
Keyword(s):  
Gene Expression ◽  
Stress Responses ◽  
Biotic Stress ◽  
Rna Silencing ◽  
Plant Responses ◽  
Developmental Processes ◽  
Endogenous Gene ◽  
Core Components ◽  
Silencing Pathways

RNA silencing refers to a conserved eukaryotic process and is regarded as one of the most important processes in plants, with the ability to regulate gene expression both transcriptionally and post-transcriptionally. Different classes of non-coding RNAs (ncRNAs) constitute key components of the RNA silencing pathways and play pivotal roles in modulating various biological processes as well as host-pathogen interactions. One of the most extensively studied classes of ncRNAs are the 20-24 nucleotide (nt) long microRNAs (miRNAs), which are core components of the endogenous gene silencing pathway. miRNAs act as negative regulators of endogenous gene expression either through mRNA-target cleavage, translational inhibition, or DNA methylation, and are inextricably linked to a plethora of developmental processes, such as leaf pattern formation as well as abiotic and biotic stress responses. In this review, we focus on the role of the RNA silencing pathways in the regulation of developmental processes as well as in the plant responses to biotic stress.

scholarly journals Plant Responses to Biotic Stress: Old Memories Matter

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 84
Author(s):  
Anirban Bhar ◽  
Amrita Chakraborty ◽  
Amit Roy
Keyword(s):  
Immune Response ◽  
Stress Responses ◽  
Biotic Stress ◽  
Current Knowledge ◽  
Adaptive Immune Response ◽  
General Concept ◽  
Immune Memory ◽  
Plant Responses ◽  
Biotic Stresses ◽  
Genomic Imprints

Plants are fascinating organisms present in most ecosystems and a model system for studying different facets of ecological interactions on Earth. In the environment, plants constantly encounter a multitude of abiotic and biotic stresses. The zero-avoidance phenomena make them more resilient to such environmental odds. Plants combat biotic stress or pathogenic ingression through a complex orchestration of intracellular signalling cascades. The plant–microbe interaction primarily relies on acquired immune response due to the absence of any specialised immunogenic cells for adaptive immune response. The generation of immune memory is mainly carried out by T cells as part of the humoral immune response in animals. Recently, prodigious advancements in our understanding of epigenetic regulations in plants invoke the “plant memory” theory afresh. Current innovations in cutting-edge genomic tools have revealed stress-associated genomic alterations and strengthened the idea of transgenerational memory in plants. In plants, stress signalling events are transferred as genomic imprints in successive generations, even without any stress. Such immunogenic priming of plants against biotic stresses is crucial for their eco-evolutionary success. However, there is limited literature capturing the current knowledge of the transgenerational memory of plants boosting biotic stress responses. In this context, the present review focuses on the general concept of memory in plants, recent advancements in this field and comprehensive implications in biotic stress tolerance with future perspectives.

scholarly journals Jasmonic Acid-Dependent MYC Transcription Factors Bind to a Tandem G-Box Motif in the YUCCA8 and YUCCA9 Promoters to Regulate Biotic Stress Responses

2021 ◽  
Vol 22 (18) ◽  
pp. 9768
Author(s):  
Marta-Marina Pérez-Alonso ◽  
Beatriz Sánchez-Parra ◽  
Paloma Ortiz-García ◽  
Maria Estrella Santamaría ◽  
Isabel Díaz ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Jasmonic Acid ◽  
Stress Responses ◽  
Pyruvic Acid ◽  
Biotic Stress ◽  
De Novo ◽  
Higher Plants ◽  
Plant Responses ◽  
Mechanical Wounding ◽  
Promoter Regions

The indole-3-pyruvic acid pathway is the main route for auxin biosynthesis in higher plants. Tryptophan aminotransferases (TAA1/TAR) and members of the YUCCA family of flavin-containing monooxygenases catalyze the conversion of l-tryptophan via indole-3-pyruvic acid to indole-3-acetic acid (IAA). It has been described that jasmonic acid (JA) locally produced in response to mechanical wounding triggers the de novo formation of IAA through the induction of two YUCCA genes, YUC8 and YUC9. Here, we report the direct involvement of a small number of basic helix-loop-helix transcription factors of the MYC family in this process. We show that the JA-mediated regulation of the expression of the YUC8 and YUC9 genes depends on the abundance of MYC2, MYC3, and MYC4. In support of this observation, seedlings of myc knockout mutants displayed a strongly reduced response to JA-mediated IAA formation. Furthermore, transactivation assays provided experimental evidence for the binding of MYC transcription factors to a particular tandem G-box motif abundant in the promoter regions of YUC8 and YUC9, but not in the promoters of the other YUCCA isogenes. Moreover, we demonstrate that plants that constitutively overexpress YUC8 and YUC9 show less damage after spider mite infestation, thereby underlining the role of auxin in plant responses to biotic stress signals.

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