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Plants (Basel, Switzerland) Aug 2023Heavy metal-associated isoprenylated plant proteins (HIPPs) are a metallochaperone-like protein family comprising a combination of structural features unique to vascular... (Review)
Review
Heavy metal-associated isoprenylated plant proteins (HIPPs) are a metallochaperone-like protein family comprising a combination of structural features unique to vascular plants. HIPPs possess both one or two heavy metal-binding domains and an isoprenylation site, facilitating a posttranslational protein lipid modification. Recent work has characterized individual HIPPs across numerous different species and provided evidence for varied functionalities. Interestingly, a significant number of HIPPs have been identified in proteomes of plasmodesmata (PD)-nanochannels mediating symplastic connectivity within plant tissues that play pivotal roles in intercellular communication during plant development as well as responses to biotic and abiotic stress. As characterized functions of many HIPPs are linked to stress responses, plasmodesmal HIPP proteins are potentially interesting candidate components of signaling events at or for the regulation of PD. Here, we review what is known about PD-localized HIPP proteins specifically, and how the structure and function of HIPPs more generally could link to known properties and regulation of PD.
PubMed: 37631227
DOI: 10.3390/plants12163015 -
International Journal of Molecular... Aug 2023Reversibly glycosylated polypeptides (RGPs) have been identified in many plant species and play an important role in cell wall formation, intercellular transport...
Reversibly glycosylated polypeptides (RGPs) have been identified in many plant species and play an important role in cell wall formation, intercellular transport regulation, and plant-virus interactions. Most plants have several genes with different expression patterns depending on the organ and developmental stage. Here, we report on four members of the RGP family in . Based on a homology search, NbRGP1-3 and NbRGP5 were assigned to the class 1 and class 2 RGPs, respectively. We demonstrated that and mRNA accumulation increases significantly in response to tobacco mosaic virus (TMV) infection. Moreover, all identified class 1 NbRGPs (as distinct from NbRGP5) suppress TMV intercellular transport and replication in . Elevated expression of led to the stimulation of callose deposition at plasmodesmata, indicating that RGP-mediated TMV local spread could be affected via a callose-dependent mechanism. It was also demonstrated that NbRGP1 interacts with TMV movement protein (MP) in vitro and in vivo. Therefore, class 1 NbRGP1-2 play an antiviral role by impeding intercellular transport of the virus by affecting plasmodesmata callose and directly interacting with TMV MP, resulting in the reduced viral spread and replication.
Topics: Nicotiana; Tobacco Mosaic Virus; Peptides; Glycosylation; Antiviral Agents
PubMed: 37629021
DOI: 10.3390/ijms241612843 -
Frontiers in Plant Science 2023Asparagus samples were examined from growing areas of Germany and selected European as well as North, Central and South American countries. Overall, 474 samples were...
Asparagus samples were examined from growing areas of Germany and selected European as well as North, Central and South American countries. Overall, 474 samples were analyzed for Asparagus virus 1 (AV1) using DAS-ELISA. In our survey, 19 AV1 isolates were further characterized. Experimental transmission to 11 species belonging to Aizoaceae, Amarantaceae, Asparagaceae, and Solanaceae succeeded. The ultrastructure of AV1 infection in asparagus has been revealed and has been compared with the one in indicator plants. The cylindrical inclusion (CI) protein, a core factor in viral replication, localized within the cytoplasm and in systemic infections adjacent to the plasmodesmata. The majority of isolates referred to pathotype I (PI). These triggered a hypersensitive resistance in inoculated leaves of spp. and were incapable of infecting spp. Only pathotype II (PII) and pathotype III (PIII) infected systemically but differed in their virulence when transmitted to spp. The newly identified PIII generated amorphous inclusion bodies and degraded chloroplasts during systemic infection but not in local lesions of infected spp. PIII probably evolved recombination in asparagus carrying a mixed infection by PI and PII. Phylogeny of the coat protein region recognized two clusters, which did not overlap with the CI-associated grouping of pathotypes. These results provide evidence for ongoing modular evolution of AV1.
PubMed: 37600206
DOI: 10.3389/fpls.2023.1187563 -
Plant Science : An International... Oct 2023Ovules are precursors of seeds and contain sporophytic integuments and gametophytic embryo sac. In Arabidopsis, embryo sac development requires highly synchronized... (Review)
Review
Ovules are precursors of seeds and contain sporophytic integuments and gametophytic embryo sac. In Arabidopsis, embryo sac development requires highly synchronized morphogenesis of integument such that defects in integument growth often accompanies with a block in megagametogenesis, indicating that integument instructs the development of female gametophytes. In this mini review, we discuss signaling pathways through which integument cells mediate embryo sac development. We also propose ways to identify key signaling factors for the communication between integument and developing female gametophyte.
Topics: Ovule; Signal Transduction; Arabidopsis; Seeds; Arabidopsis Proteins
PubMed: 37574141
DOI: 10.1016/j.plantsci.2023.111829 -
Molecular Plant Pathology Dec 2023The genus Potyvirus is considered as the largest among plant single-stranded (positive-sense) RNA viruses, causing considerable economic damage to vegetable and fruit... (Review)
Review
The genus Potyvirus is considered as the largest among plant single-stranded (positive-sense) RNA viruses, causing considerable economic damage to vegetable and fruit crops worldwide. Through the coordinated action of four viral proteins and a few identified host factors, potyviruses exploit the endomembrane system of infected cells for their replication and for their intra- and intercellular movement to and through plasmodesmata (PDs). Although a significant amount of data concerning potyvirus movement has been published, no synthetic review compiling and integrating all information relevant to our current understanding of potyvirus transport is available. In this review, we highlight the complexity of potyvirus movement pathways and present three potential nonexclusive mechanisms based on (1) the use of the host endomembrane system to produce membranous replication vesicles that are targeted to PDs and move from cell to cell, (2) the movement of extracellular viral vesicles in the apoplasm, and (3) the transport of virion particles or ribonucleoprotein complexes through PDs. We also present and discuss experimental data supporting these different models as well as the aspects that still remain mostly speculative.
Topics: Potyvirus; Viral Proteins; Plant Diseases; Nicotiana
PubMed: 37571979
DOI: 10.1111/mpp.13383 -
Nature Plants Sep 2023In plants, restoring intercellular communication is required for cell activity in buds during the growth transition from slow to fast growth after dormancy release....
In plants, restoring intercellular communication is required for cell activity in buds during the growth transition from slow to fast growth after dormancy release. However, the epigenetic regulation of this phenomenon is far from understood. Here we demonstrate that lily VERNALIZATION INSENSITIVE 3-LIKE 1 (LoVIL1) confers growth transition by mediating plasmodesmata opening via epigenetic repression of CALLOSE SYNTHASE 3 (LoCALS3). Moreover, we found that a novel transcription factor, NUCLEAR FACTOR Y, SUBUNIT A7 (LoNFYA7), is capable of recruiting the LoVIL1-Polycomb Repressive Complex 2 (PRC2) and enhancing H3K27me3 at the LoCALS3 locus by recognizing the CCAAT cis-element (Cce) of its promoter. The LoNFYA7-LoVIL1 module serves as a key player in orchestrating the phase transition from slow to fast growth in lily bulbs. These studies also indicate that LoVIL1 is a suitable marker for the bud-growth-transition trait following dormancy release in lily cultivars.
Topics: Epigenesis, Genetic; Lilium; Glucosyltransferases; Polycomb Repressive Complex 2; Gene Expression Regulation, Plant
PubMed: 37563458
DOI: 10.1038/s41477-023-01492-z -
Functional & Integrative Genomics Aug 2023Rice (Oryza sativa L.) is one of the most important dietary carbohydrate sources for half of the world's population. However, it is not well adapted to environmental...
Rice (Oryza sativa L.) is one of the most important dietary carbohydrate sources for half of the world's population. However, it is not well adapted to environmental stress conditions, necessitating to create new and improved varieties to help ensure sufficient rice production in the face of rising populations and shrinking arable land. Recently, the development of the CRISPR/Cas9 gene editing system has allowed researchers to study functional genomics and engineer new rice varieties with great efficiency compared to conventional methods. In this study, we investigate the involvement of OsGER4, a germin-like protein identified by a genome-wide association study that is associated with rice root development under a stress hormone jasmonic acids treatment. Analysis of the OsGER4 promoter region revealed a series of regulatory elements that connect this gene to ABA signaling and water stress response. Under heat stress, osger4 mutant lines produce a significantly lower crown root than wild-type Kitaake rice. The loss of OsGER4 also led to the reduction of lateral root development. Using the GUS promoter line, OsGER4 expression was detected in the epidermis of the crown root primordial, in the stele of the crown root, and subsequently in the primordial of the lateral root. Taken together, these results illustrated the involvement of OsGER4 in root development under heat stress by regulating auxin transport through plasmodesmata, under control by both ABA and auxin signaling.
Topics: Oryza; Plant Roots; Genome-Wide Association Study; Plant Proteins; Heat-Shock Response; Indoleacetic Acids; Gene Expression Regulation, Plant
PubMed: 37561192
DOI: 10.1007/s10142-023-01201-1 -
Virology Oct 2023Over the past decades, several studies have examined the subcellular localization of the cauliflower mosaic virus (CaMV) P6 protein by tagging it with GFP (P6-GFP)....
Transient expression of cauliflower mosaic virus (CaMV) P6-GFP complements a defective CaMV replicon to facilitate viral gene expression, replication and virion formation.
Over the past decades, several studies have examined the subcellular localization of the cauliflower mosaic virus (CaMV) P6 protein by tagging it with GFP (P6-GFP). These investigations have been essential in the development of models for inclusion body formation, nuclear transport, and microfilament-associated intracellular movement of P6 inclusion bodies for delivery of virions to plasmodesmata. Although it was shown early on that the translational transactivation function of P6-GFP was comparable to wild type P6, it has not been possible to incorporate a P6-GFP gene into an infectious clone of CaMV. Consequently, it has not been possible to formally prove that a P6-GFP fusion is comparable in function to the unmodified P6 protein. Here we show that transient expression of P6-GFP can complement a defective CaMV replicon through gene expression, replication and encapsidation, which validates the relevance of P6-GFP subcellular localization studies for understanding the development of CaMV infections.
PubMed: 37556874
DOI: 10.1016/j.virol.2023.109854 -
Frontiers in Plant Science 2023Arbuscular mycorrhizal (AM) fungi and rhizobia form two of the most important plant-microbe associations for the assimilation of phosphorus (P) and nitrogen (N)....
Arbuscular mycorrhizal (AM) fungi and rhizobia form two of the most important plant-microbe associations for the assimilation of phosphorus (P) and nitrogen (N). Symbiont-derived signals are able to coordinate the infection process by triggering multiple responses in the plant root, such as calcium influxes and oscillations, increased reactive oxygen species (ROS), cytoskeletal rearrangements and altered gene expression. An examination was made of the role of tetraspanins, which are transmembrane proteins that self-organize into tetraspanin web regions, where they recruit specific proteins into platforms required for signal transduction, membrane fusion, cell trafficking, and ROS generation. In plant cells, tetraspanins are scaffolding proteins associated with root radial patterning, biotic and abiotic stress responses, cell fate determination, plasmodesmata and hormonal regulation. Some plant tetraspanins, such as TETRASPANIN 8 and TETRASPANIN 9 (AtTET8 and AtTET9) are associated with exosomes during inter-kingdom communication. In this study, a homolog of , , in common bean ( var. Negro Jamapa) was examined in roots during interactions with and . The promoter of contained several acting regulatory DNA elements potentially related to mutualistic interactions, and was transcriptionally activated during AM fungal and rhizobial associations. Silencing it decreased the size and number of nodules, nitrogen fixation, and mycorrhizal arbuscule formation, whereas overexpressing it increased the size and number of nodules, and mycorrhizal arbuscule formation but decreased nitrogen fixation. appears to be an important element in both of these mutualistic interactions, perhaps through its interaction with NADPH oxidase and the generation of ROS during the infection processes.
PubMed: 37465390
DOI: 10.3389/fpls.2023.1152493 -
Protoplasma Jan 2024In this study, the results of the first detection of callose within the ovules of the representatives of the family Crassulaceae are presented. This study was carried...
In this study, the results of the first detection of callose within the ovules of the representatives of the family Crassulaceae are presented. This study was carried out on three species of the genus Sedum. Data analysis showed differences in the callose deposition pattern between Sedum hispanicum and Sedum ser. Rupestria species during megasporogenesis. Callose was present mostly in the transversal walls of dyads and tetrads in S. hispanicum. Furthermore, a complete loss of callose from the cell walls of the linear tetrad and a gradual and simultaneous deposition of callose within the nucellus of S. hispanicum were observed. The findings of this study showed the presence of hypostase with callose in the ovules of S. hispanicum, which is not common in other angiosperms. The remaining species tested in this study-Sedum sediforme and Sedum rupestre-showed a typical, well-known callose deposition pattern for plants with the monospore type of megasporogenesis and the Polygonum type of embryo sac. The functional megaspore (FM) in all studied species was located most chalazally. FM is a mononuclear cell, which wall is callose-free in the chalazal pole. The study presents the causes of different patterns of callose deposition within Sedum and their relationship with the systematic position of the study species. Moreover, embryological studies present an argument for excluding callose as a substance that forms an electron-dense material near the plasmodesmata in megaspores of S. hispanicum. This research expands the knowledge about the embryological processes of succulent plants from the family Crassulaceae.
Topics: Sedum; Crassulaceae; Gametogenesis, Plant; Plasmodesmata; Glucans
PubMed: 37418158
DOI: 10.1007/s00709-023-01879-x