RNA silencing pathways in plant development and defense

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.

Download Full-text

Effects of Abscisic Acid and Salicylic Acid on Gene Expression in the Antiviral RNA Silencing Pathway in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms20102538 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2538 ◽

Cited By ~ 8

Author(s):

Mazen Alazem ◽

Kook-Hyung Kim ◽

Na-Sheng Lin

Keyword(s):

Gene Expression ◽

Salicylic Acid ◽

Abscisic Acid ◽

Stress Responses ◽

Binding Sites ◽

Virus Resistance ◽

Rna Silencing ◽

Multiple Binding Sites ◽

Multiple Binding ◽

Silencing Pathways

The RNA silencing pathways modulate responses to certain stresses, and can be partially tuned by several hormones such as salicylic acid (SA) and abscisic acid (ABA). Although SA and ABA are often antagonistic and often modulate different stress responses, they have similar effects on virus resistance, which are partially achieved through the antiviral RNA silencing pathway. Whether they play similar roles in regulating the RNA silencing pathway is unclear. By employing coexpression and promoter analyses, we found that some ABA- and SA-related transcription factors (TFs) are coexpressed with several AGO, DCL, and RDR genes, and have multiple binding sites for the identified TFs in the queried promoters. ABA and SA are antagonistic with respect to the expression of AGO1 and RDRs because ABA was able to induce these genes only in the SA mutant. Nevertheless, both hormones showed similarities in the regulation of other genes, for example, the induction of AGO2 by ABA was SA-dependent, indicating that ABA acts upstream of SA in this regulation. We inferred that the similar effects of ABA and SA on some genes resulted in the redundancy of their roles in resistance to bamboo mosaic virus, but that the two hormones are antagonistic with respect to other genes unrelated to their biosynthesis pathways.

Download Full-text

The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress

International Journal of Molecular Sciences ◽

10.3390/ijms21176082 ◽

2020 ◽

Vol 21 (17) ◽

pp. 6082 ◽

Cited By ~ 1

Author(s):

Yi Zhang ◽

Aihong Zhang ◽

Xiuming Li ◽

Congming Lu

Keyword(s):

Gene Expression ◽

Environmental Stress ◽

Stress Responses ◽

Light Stress ◽

High Light ◽

Plant Responses ◽

Chloroplast Gene ◽

Chloroplast Gene Expression ◽

Endosymbiotic Origin

Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment.

Download Full-text

The role of REST/NRSF in regulating endogenous gene expression

Biochemical Society Transactions ◽

10.1042/bst027a125b ◽

1999 ◽

Vol 27 (3) ◽

pp. A125-A125

Author(s):

I.C. Wood ◽

M. Mistry ◽

A. Roopra ◽

N.J. Buckley

Keyword(s):

Gene Expression ◽

Endogenous Gene

Download Full-text

Fungal Production and Manipulation of Plant Hormones

Current Medicinal Chemistry ◽

10.2174/0929867324666170314150827 ◽

2018 ◽

Vol 25 (2) ◽

pp. 253-267 ◽

Cited By ~ 8

Author(s):

Sandra Fonseca ◽

Dhanya Radhakrishnan ◽

Kalika Prasad ◽

Andrea Chini

Keyword(s):

Stress Responses ◽

Current Knowledge ◽

Critical Role ◽

Plant Defence ◽

Pathogenic Fungi ◽

Plant Responses ◽

Defensive Strategies ◽

Hormone Balance ◽

Living Organisms

Living organisms are part of a highly interconnected web of interactions, characterised by species nurturing, competing, parasitizing and preying on one another. Plants have evolved cooperative as well as defensive strategies to interact with neighbour organisms. Among these, the plant-fungus associations are very diverse, ranging from pathogenic to mutualistic. Our current knowledge of plant-fungus interactions suggests a sophisticated coevolution to ensure dynamic plant responses to evolving fungal mutualistic/pathogenic strategies. The plant-fungus communication relies on a rich chemical language. To manipulate the plant defence mechanisms, fungi produce and secrete several classes of biomolecules, whose modeof- action is largely unknown. Upon perception of the fungi, plants produce phytohormones and a battery of secondary metabolites that serve as defence mechanism against invaders or to promote mutualistic associations. These mutualistic chemical signals can be co-opted by pathogenic fungi for their own benefit. Among the plant molecules regulating plant-fungus interaction, phytohormones play a critical role since they modulate various aspects of plant development, defences and stress responses. Intriguingly, fungi can also produce phytohormones, although the actual role of fungalproduced phytohormones in plant-fungus interactions is poorly understood. Here, we discuss the recent advances in fungal production of phytohormone, their putative role as endogenous fungal signals and how fungi manipulate plant hormone balance to their benefits.

Download Full-text

Viral Virulence Protein Suppresses RNA Silencing–Mediated Defense but Upregulates the Role of MicroRNA in Host Gene Expression

The Plant Cell ◽

10.1105/tpc.018986 ◽

2004 ◽

Vol 16 (5) ◽

pp. 1302-1313 ◽

Cited By ~ 178

Author(s):

Jun Chen ◽

Wan Xiang Li ◽

Daoxin Xie ◽

Jin Rong Peng ◽

Shou Wei Ding

Keyword(s):

Gene Expression ◽

Rna Silencing ◽

Host Gene ◽

Host Gene Expression ◽

Viral Virulence ◽

Virulence Protein

Download Full-text

Epigenetic Influences on Plant Responses to the Environment [University of Wisconsin - Oshkosh]

Journal of Student Research ◽

10.47611/jsr.vi.624 ◽

2019 ◽

Author(s):

Angela L Vickman ◽

Travis Smith ◽

Hayley Vandenboom ◽

Lisa A. Dorn

Keyword(s):

Gene Expression ◽

Phenotypic Plasticity ◽

Molecular Mechanisms ◽

Molecular Level ◽

Physical Structure ◽

Plant Responses ◽

Appropriate Behavior ◽

Stressful Environment ◽

University Of Wisconsin

Plants and animals may respond to changes in the environment at the molecular level by changing the amount of a gene product (a protein) to generate the appropriate behavior or physical structure (a phenotype) for that environment. For example, an extremely stressful environment can cause plants to reproduce immediately rather than waiting for conditions to improve. The molecular mechanisms for changing phenotype with environment (phenotypic plasticity) are not clear, however previous studies have shown plasticity may be the result of failing to change expression to maintain a phenotype or a deliberate change in expression altering the phenotype. To explore the molecular mechanisms underlying phenotypic plasticity, I am using a minION sequencing apparatus to re-sequence three inbred lines of Arabidopsis thaliana with extreme phenotypic plasticity differences and gene expression differences with the environment. I will specifically explore the role of methylated cytosines and adenines in gene expression.

Download Full-text

Phosphorylation of Serine114 of the transcription factor ABSCISIC ACID INSENSITIVE 4 is essential for activity

10.1101/2020.08.14.250936 ◽

2020 ◽

Author(s):

Nadav Eisner ◽

Tzofia Maymon ◽

Ester Cancho Sanchez ◽

Dana Bar-Zvi ◽

Sagie Brodsky ◽

...

Keyword(s):

Gene Expression ◽

Transcription Factor ◽

Stress Responses ◽

Lateral Root ◽

Map Kinases ◽

Regulation Of Gene Expression ◽

List Type ◽

Lateral Root Development ◽

Aba Insensitive

AbstractThe transcription factor ABA-INSENSITIVE(ABI)4 has diverse roles in regulating plant growth, including inhibiting germination and reserve mobilization in response to ABA and high salinity, inhibiting seedling growth in response to high sugars, inhibiting lateral root growth, and repressing light-induced gene expression. ABI4 activity is regulated at multiple levels, including gene expression, protein stability, and activation by phosphorylation. Although ABI4 can be phosphorylated at multiple residues by MAPKs, we found that S114 is the preferred site of MPK3. To examine the possible biological role of S114 phosphorylation, we transformed abi4-1 mutant plants with ABI4pro::ABI4 constructs encoding wild type (114S), phosphorylation-null (S114A) or phosphomimetic (S114E) forms of ABI4. Phosphorylation of S114 is necessary for the response to ABA, glucose, salt stress, and lateral root development, where the abi4 phenotype could be complemented by expressing ABI4(114S) or ABI4(S114E) but not ABI4(S114A). Comparison of root transcriptomes in ABA-treated roots of abi4-1 mutant plants transformed with constructs encoding the different phosphorylation-forms of S114 of ABI4 revealed that 85% of the ABI4-regulated genes whose expression pattern could be restored by expressing ABI4(114S) are down-regulated by ABI4. Over half of the ABI4-modulated genes were independent of the phosphorylation state of ABI4; these are enriched for stress responses. Phosphorylation of S114 was required for regulation of 35% of repressed genes, but only 17% of induced genes. The genes whose repression requires the phosphorylation of S114 are mainly involved in embryo and seedling development, growth and differentiation, and regulation of gene expression.HighlightsTranscription factor ABI4 is a substrate of MAP kinases.MPK3 preferentially phosphorylates Serine 114 of ABI4.Phosphorylated Serine 114 of ABI4 is required for the complementation of abi4 mutants.Phosphorylated ABI4 acts primarily as a repressor.

Download Full-text

BRS1 mediates plant redox regulation and cold responses

10.21203/rs.3.rs-59649/v2 ◽

2021 ◽

Author(s):

Dongzhi Zhang ◽

Yuqian Zhao ◽

Junzhe Wang ◽

Peng Zhao ◽

Shengbao Xu

Keyword(s):

Cold Stress ◽

Stress Responses ◽

Isocitrate Dehydrogenase ◽

Redox Regulation ◽

Serine Carboxypeptidase ◽

Developmental Processes ◽

Brassinosteroid Signaling ◽

Cold Responses ◽

Precise Role

Abstract Background: Brassinosteroid-insensitive 1 suppressor 1 (BRS1), is a serine carboxypeptidase that mediates brassinosteroid signaling and participates in multiple developmental processes in Arabidopsis. However, little is known about the precise role of BRS1 in this context. Results: In this study, we analyzed transcriptional and proteomic profiles of Arabidopsis seedlings overexpressing BRS1 and found that this gene is involved in both cold stress responses and redox regulation. Further proteomic evidence shows that BRS1 regulates cell redox by indirectly interacting with cytosolic NADP+-dependent isocitrate dehydrogenase (cICDH). We identified two novel splice products of BRS1, which might play important roles in development and stress responses in plants. Conclusions: This study highlights the role of BRS1 in plant redox regulation and stress responses, which extends our understanding of extracellular serine carboxypeptidases.

Download Full-text