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The New Phytologist Sep 2022
PubMed: 35979686
DOI: 10.1111/nph.18346 -
The Plant Cell Sep 2023Emerging evidence indicates that in addition to its well-recognized functions in antiviral RNA silencing, dsRNA elicits pattern-triggered immunity (PTI), likely...
Emerging evidence indicates that in addition to its well-recognized functions in antiviral RNA silencing, dsRNA elicits pattern-triggered immunity (PTI), likely contributing to plant resistance against virus infections. However, compared to bacterial and fungal elicitor-mediated PTI, the mode-of-action and signaling pathway of dsRNA-induced defense remain poorly characterized. Here, using multicolor in vivo imaging, analysis of GFP mobility, callose staining, and plasmodesmal marker lines in Arabidopsis thaliana and Nicotiana benthamiana, we show that dsRNA-induced PTI restricts the progression of virus infection by triggering callose deposition at plasmodesmata, thereby likely limiting the macromolecular transport through these cell-to-cell communication channels. The plasma membrane-resident SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE 1, the BOTRYTIS INDUCED KINASE1/AVRPPHB SUSCEPTIBLE1-LIKE KINASE1 kinase module, PLASMODESMATA-LOCATED PROTEINs 1/2/3, as well as CALMODULIN-LIKE 41 and Ca2+ signals are involved in the dsRNA-induced signaling leading to callose deposition at plasmodesmata and antiviral defense. Unlike the classical bacterial elicitor flagellin, dsRNA does not trigger a detectable reactive oxygen species (ROS) burst, substantiating the idea that different microbial patterns trigger partially shared immune signaling frameworks with distinct features. Likely as a counter strategy, viral movement proteins from different viruses suppress the dsRNA-induced host response leading to callose deposition to achieve infection. Thus, our data support a model in which plant immune signaling constrains virus movement by inducing callose deposition at plasmodesmata and reveals how viruses counteract this layer of immunity.
PubMed: 37378592
DOI: 10.1093/plcell/koad176 -
Plant Physiology Jan 2020Localization of mRNAs at the subcellular level is an essential mechanism for specific protein targeting and local control of protein synthesis in both eukaryotes and... (Review)
Review
Localization of mRNAs at the subcellular level is an essential mechanism for specific protein targeting and local control of protein synthesis in both eukaryotes and bacteria. While mRNA localization is well documented in metazoans, somatic cells, and microorganisms, only a handful of well-defined mRNA localization examples have been reported in vascular plants and algae. This review summarizes the function and mechanism of mRNA localization and highlights recent studies of mRNA localization in vascular plants. While the emphasis focuses on storage protein mRNA localization in rice endosperm cells, information on targeting of RNAs to organelles (chloroplasts and mitochondria) and plasmodesmata is also discussed.
Topics: Plant Cells; RNA, Messenger; RNA, Plant
PubMed: 31611420
DOI: 10.1104/pp.19.00972 -
Annual Review of Virology Sep 2021Viroids are small, single-stranded, circular RNAs infecting plants. Composed of only a few hundred nucleotides and being unable to code for proteins, viroids represent... (Review)
Review
Viroids are small, single-stranded, circular RNAs infecting plants. Composed of only a few hundred nucleotides and being unable to code for proteins, viroids represent the lowest level of complexity for an infectious agent, even below that of the smallest known viruses. Despite the relatively small size, viroids contain RNA structural elements embracing all the information needed to interact with host factors involved in their infectious cycle, thus providing models for studying structure-function relationships of RNA. Viroids are specifically targeted to nuclei (family ) or chloroplasts (family ), where replication based on rolling-circle mechanisms takes place. They move locally and systemically through plasmodesmata and phloem, respectively, and may elicit symptoms in the infected host, with pathogenic pathways linked to RNA silencing and other plant defense responses. In this review, recent advances in the dissection of the complex interplay between viroids and plants are presented, highlighting knowledge gaps and perspectives for future research.
Topics: Plant Diseases; Plants; RNA Interference; RNA, Viral; Viroids
PubMed: 34255541
DOI: 10.1146/annurev-virology-091919-092331 -
Molecular Plant-microbe Interactions :... Feb 2022Being sessile, plants are continuously challenged by changes in their surrounding environment and must survive and defend themselves against a multitude of pathogens.... (Review)
Review
Being sessile, plants are continuously challenged by changes in their surrounding environment and must survive and defend themselves against a multitude of pathogens. Plants have evolved a mode for pathogen recognition that activates signaling cascades such as reactive oxygen species, mitogen-activated protein kinase, and Ca pathways, in coordination with hormone signaling, to execute the defense response at the local and systemic levels. Phytopathogens have evolved to manipulate cellular and hormonal signaling and exploit hosts' cell-to-cell connections in many ways at multiple levels. Overall, triumph over pathogens depends on how efficiently the pathogens are recognized and how rapidly the plant response is initiated through efficient intercellular communication via apoplastic and symplastic routes. Here, we review how intercellular communication in plants is mediated, manipulated, and maneuvered during plant-pathogen interaction.[Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2022.
Topics: Cell Communication; Plants
PubMed: 34664986
DOI: 10.1094/MPMI-09-21-0221-CR -
The New Phytologist Sep 2021Characterising the processes that control auxin dynamics is essential to understanding how auxin regulates plant development. Over recent years, several studies have... (Review)
Review
Characterising the processes that control auxin dynamics is essential to understanding how auxin regulates plant development. Over recent years, several studies have investigated auxin diffusion through plasmodesmata, characterising this cell-to-cell diffusion and demonstrating that it affects auxin distributions. Furthermore, studies have shown that plasmodesmatal auxin diffusion affects developmental processes, including phototropism, lateral root emergence and leaf hyponasty. This short Tansley Insight review describes how these studies have contributed to our understanding of auxin dynamics and discusses potential future directions in this area.
Topics: Gene Expression Regulation, Plant; Indoleacetic Acids; Phototropism; Plant Development; Plant Roots; Plasmodesmata
PubMed: 34053083
DOI: 10.1111/nph.17517 -
Molecular Plant Pathology Jun 2022Plants perceive an assortment of external cues during their life cycle, including abiotic and biotic stressors. Biotic stress from a variety of pathogens, including... (Review)
Review
Plants perceive an assortment of external cues during their life cycle, including abiotic and biotic stressors. Biotic stress from a variety of pathogens, including viruses, oomycetes, fungi, and bacteria, is considered to be a substantial factor hindering plant growth and development. To hijack the host cell's defence machinery, plant pathogens have evolved sophisticated attack strategies mediated by numerous effector proteins. Several studies have indicated that plasmodesmata (PD), symplasmic pores that facilitate cell-to-cell communication between a cell and neighbouring cells, are one of the targets of pathogen effectors. However, in contrast to plant-pathogenic viruses, reports of fungal- and bacterial-encoded effectors that localize to and exploit PD are limited. Surprisingly, a recent study of PD-associated bacterial effectors has shown that a number of bacterial effectors undergo cell-to-cell movement via PD. Here we summarize and highlight recent advances in the study of PD-associated fungal/oomycete/bacterial effectors. We also discuss how pathogen effectors interfere with host defence mechanisms in the context of PD regulation.
Topics: Host-Pathogen Interactions; Oomycetes; Plant Diseases; Plants; Plasmodesmata
PubMed: 34569687
DOI: 10.1111/mpp.13142 -
Frontiers in Plant Science 2021Plasmodesmata (PD) are cytoplasmic canals that facilitate intercellular communication and molecular exchange between adjacent plant cells. PD-associated proteins are... (Review)
Review
Plasmodesmata (PD) are cytoplasmic canals that facilitate intercellular communication and molecular exchange between adjacent plant cells. PD-associated proteins are considered as one of the foremost factors in regulating PD function that is critical for plant development and stress responses. Although its potential to be used for crop engineering is enormous, our understanding of PD biology was relatively limited to model plants, demanding further studies in crop systems. Recently developed genome editing techniques such as Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associate protein (CRISPR/Cas) might confer powerful approaches to dissect the molecular function of PD components and to engineer elite crops. Here, we assess several aspects of PD functioning to underline and highlight the potential applications of CRISPR/Cas that provide new insight into PD biology and crop improvement.
PubMed: 34149780
DOI: 10.3389/fpls.2021.679140 -
Life (Basel, Switzerland) Nov 2022The necessity to include plants as a component of a Bioregenerative Life Support System leads to investigations to optimize plant growth facilities as well as a better... (Review)
Review
The necessity to include plants as a component of a Bioregenerative Life Support System leads to investigations to optimize plant growth facilities as well as a better understanding of the plant cell membrane and its numerous activities in the signaling, transport, and sensing of gravity, drought, and other stressors. The cell membrane participates in numerous processes, including endo- and exocytosis and cell division, and is involved in the response to external stimuli. Variable but stabilized microdomains form in membranes that include specific lipids and proteins that became known as (detergent-resistant) membrane microdomains, or lipid rafts with various subclassifications. The composition, especially the sterol-dependent recruitment of specific proteins affects endo- and exo-membrane domains as well as plasmodesmata. The enhanced saturated fatty acid content in lipid rafts after clinorotation suggests increased rigidity and reduced membrane permeability as a primary response to abiotic and mechanical stress. These results can also be obtained with lipid-sensitive stains. The linkage of the CM to the cytoskeleton via rafts is part of the complex interactions between lipid microdomains, mechanosensitive ion channels, and the organization of the cytoskeleton. These intricately linked structures and functions provide multiple future research directions to elucidate the role of lipid rafts in physiological processes.
PubMed: 36362962
DOI: 10.3390/life12111809 -
Molecular Plant Pathology Apr 2020RNA interference is a biological process whereby small RNAs inhibit gene expression through neutralizing targeted mRNA molecules. This process is conserved in... (Review)
Review
RNA interference is a biological process whereby small RNAs inhibit gene expression through neutralizing targeted mRNA molecules. This process is conserved in eukaryotes. Here, recent work regarding the mechanisms of how small RNAs move within and between organisms is examined. Small RNAs can move locally and systemically in plants through plasmodesmata and phloem, respectively. In fungi, transportation of small RNAs may also be achieved by septal pores and vesicles. Recent evidence also supports bidirectional cross-kingdom communication of small RNAs between host plants and adapted fungal pathogens to affect the outcome of infection. We discuss several mechanisms for small RNA trafficking and describe evidence for transport through naked form, combined with RNA-binding proteins or enclosed by vesicles.
Topics: Extracellular Vesicles; Fungi; Phloem; Plasmodesmata; RNA Interference; RNA, Plant
PubMed: 32027079
DOI: 10.1111/mpp.12911