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Morales-Martinez, P.

Publications and source records attributed to Morales-Martinez, P..

2 recordsLinked to original sources

Extracellular vesicles associate with infectious geminiviral particles in the apoplast of infected plants.

Plant viruses have evolved diverse strategies to facilitate their movement and survival within the host. Among them, geminiviruses co-opt host cellular machinery to replicate and disseminate. Traditionally, viral propagation has been associated with intercellular symplastic trafficking mediated by plasmodesmata and viral movement proteins. However, recent evidence demonstrated that the plant RNA virus turnip mosaic virus (TuMV) components are associated with extracellular vesicles (EVs). EVs are membrane-bound structures secreted to the extracellular space to potentially mediate several plant-pathogen interactions such as cross-kingdom RNA interference or the delivery of stress response proteins. In animals, EVs facilitate viral transmission both within the host and across species, but knowledge about their potential roles in plant viral infection is scarce. In this study, we demonstrate that EVs isolated from geminivirus-infected plants contain complete viral genomes and both capsid and viral movement proteins. Furthermore, these EV fractions were demonstrated to be infectious when mechanically inoculated onto naive plants. This discovery suggests that EVs may serve as alternative carriers for geminivirus components, enabling long-range transport or potentially modulating host immune responses, and highlights geminiviral capacity to transverse membrane boundaries, essential for circulative arbovirus propagation in their insect vectors. Significance StatementViruses are obligate intracellular parasites that shape ecological communities and crucially challenge animal and plant health worldwide. Conversely to animal viruses, plant-infecting viruses rely on plasmodesmata to disseminate through their host and establish systemic infection. Nonetheless, most plant viruses are insect-transmitted whose ecological cycle relies on their insect vector spread. Thus, strategies to cross continuous membrane barriers are essential for their dissemination and may be potentially conserved in plant hosts. Our discovery that infectious viral entities are associated with EVs reveals an alternative pathway for geminiviral movement within plant hosts that could facilitate vector transmission, challenging our long-standing understanding of plant virus biology and expanding the current conception of plant viral pathology.

plant biology↗

Defender or accomplice? Dual roles of plant vesicle trafficking in restricting and enabling geminiviral systemic infection.

The vesicle trafficking system enables multidirectional cargo fluxes between endomembrane compartments, ensuring the viability of eukaryotic cells. However, vesicle trafficking plays dual roles during pathogen infections. In plants, the endomembrane system mediates autophagic immune responses but can also be hijacked by pathogens to facilitate successful infections. In this study, we demonstrate that vesicle trafficking machinery acts as a double-edged sword during infection by the geminivirus tomato yellow leaf curl Sardinia virus (TYLCSaV) in Nicotiana benthamiana. Virus-induced gene silencing (VIGS) of eight genes encoding key vesicle trafficking regulators revealed contrasting outcomes. Silencing of NbSAR1 and NbAP-1{gamma} significantly increased systemic geminiviral DNA accumulation, whereas silencing of Nb{delta}-COP, NbARF1, and clathrin genes almost completely abolished infection. Notably, this inhibition is hypothesized to result from direct or indirect impairment in viral movement, as replication remained unaffected by gene silencing. Furthermore, the observed effects affect other geminiviruses, including tomato yellow leaf curl virus (TYLCV) and beet curly top virus (BCTV), but not unrelated pathogens such as the RNA potato virus X (PVX) or the plant pathogenic bacterium Pseudomonas syringae. These findings suggest that while the vacuolar and autophagy branches of the vesicle trafficking system might mediate antiviral autophagic defense responses, the integrity of endocytosis and retrograde transport is essential for systemic geminiviral infection.

plant biology↗