Publications by authors named "Laura G C Martins"

Protoplasts are isolated plant cells from which the cell walls have been removed by treatment with fungal cellulase and macerozyme enzymes, which degrade the primary components of the cell wall. The protoplasts are totipotent, sensitive, and versatile; thereby, they have been extensively used to study signal transduction pathways, cell-autonomous responses, and replication of plant viruses. This system has several advantages over the use of whole plants for viral replication, including a high percentage of infected cells and uncoupling virus movement from replication assays.

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Because of limited free diffusion in the cytoplasm, viruses must use active transport mechanisms to move intracellularly. Nevertheless, how the plant single-stranded DNA begomoviruses hijack the host intracytoplasmic transport machinery to move from the nucleus to the plasmodesmata remains enigmatic. Here, we identified nuclear shuttle protein (NSP)-interacting proteins from Arabidopsis (Arabidopsis thaliana) by probing a protein microarray and demonstrated that the cabbage leaf curl virus NSP, a facilitator of the nucleocytoplasmic trafficking of viral (v)DNA, interacts in planta with an endosomal vesicle-localized, plant-specific syntaxin-6 protein, designated NSP-interacting syntaxin domain-containing protein (NISP).

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Begomoviruses ( family) represent a severe constraint to agriculture worldwide. As ssDNA viruses that replicate in the nuclei of infected cells, the nascent viral DNA has to move to the cytoplasm and then to the adjacent cell to cause disease. The begomovirus nuclear shuttle protein (NSP) assists the intracellular transport of viral DNA from the nucleus to the cytoplasm and cooperates with the movement protein (MP) for the cell-to-cell translocation of viral DNA to uninfected cells.

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The Geminiviridae family is one of the most successful and largest families of plant viruses that infect a large variety of important dicotyledonous and monocotyledonous crops and cause significant yield losses worldwide. This broad spectrum of host range is only possible because geminiviruses have evolved sophisticated strategies to overcome the arsenal of antiviral defenses in such diverse plant species. In addition, geminiviruses evolve rapidly through recombination and pseudo-recombination to naturally create a great diversity of virus species with divergent genome sequences giving the virus an advantage over the host recognition system.

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Plants deploy various immune receptors to recognize pathogens and defend themselves. Crosstalk may happen among receptor-mediated signal transduction pathways in the same host during simultaneous infection of different pathogens. However, the related function of the receptor-like kinases (RLKs) in thwarting different pathogens remains elusive.

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Acidic soils, where aluminum (Al) toxicity is a major agricultural constraint, are globally widespread and are prevalent in developing countries. In sorghum, the root citrate transporter SbMATE confers Al tolerance by protecting root apices from toxic Al, but can exhibit reduced expression when introgressed into different lines. We show that allele-specific transactivation occurs and is caused by factors located away from Using expression-QTL mapping and expression genome-wide association mapping, we establish that transcription is controlled in a bipartite fashion, primarily in but also in Multiallelic promoter transactivation and ChIP analyses demonstrated that intermolecular effects on expression arise from a WRKY and a zinc finger-DHHC transcription factor (TF) that bind to and -activate the promoter.

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