Responsiveness to environmental conditions and developmental plasticity of root systems are crucial determinants of plant fitness. These processes are interconnected at a cellular level with cell wall properties and cell surface signaling, which involve arabinogalactan proteins (AGPs) as essential components. AGPs are cell-wall localized glycoproteins, often GPI-anchored, which participate in root functions at many levels. They are involved in cell expansion and differentiation, regulation of root growth, interactions with other organisms, and environmental response. Due to the complexity of cell wall functional and regulatory networks, and despite the large amount of experimental data, the exact molecular mechanisms of AGP-action are still largely unknown. This dynamically evolving field of root biology is summarized in the present review.

• Keywords
• AGP, GPI anchor, arabinogalactan proteins, fasciclin-like, interactions, root growth, root hairs,
• Publication type
• Journal Article MeSH
• Review MeSH

Banana Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc) is one of the most destructive soil-borne diseases. In this study, young tissue-cultured plantlets of banana (Musa spp. AAA) cultivars differing in Foc susceptibility were used to reveal their differential responses to this pathogen using digital gene expression (DGE). Data were evaluated by various bioinformatic tools (Venn diagrams, gene ontology (GO) annotation and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses) and immunofluorescence labelling method to support the identification of gene candidates determining the resistance of banana against Foc. Interestingly, we have identified MaWRKY50 as an important gene involved in both constitutive and induced resistance. We also identified new genes involved in the resistance of banana to Foc, including several other transcription factors (TFs), pathogenesis-related (PR) genes and some genes related to the plant cell wall biosynthesis or degradation (e.g., pectinesterases, β-glucosidases, xyloglucan endotransglucosylase/hydrolase and endoglucanase). The resistant banana cultivar shows activation of PR-3 and PR-4 genes as well as formation of different constitutive cell barriers to restrict spreading of the pathogen. These data suggest new mechanisms of banana resistance to Foc.

• Keywords
• DGE, GO annotation, KEGG pathways, Venn diagram, banana Fusarium wilt, resistance genes,
• MeSH
• Molecular Sequence Annotation MeSH
• Musa genetics   microbiology   MeSH
• Fluorescent Antibody Technique MeSH
• Fusarium * MeSH
• Gene Ontology MeSH
• Plant Roots genetics   MeSH
• Disease Susceptibility MeSH
• Plant Diseases genetics   microbiology   MeSH
• Disease Resistance MeSH
• Polymerase Chain Reaction MeSH
• Gene Expression Regulation, Plant * MeSH
• Gene Expression Profiling MeSH
• Transcriptome * MeSH
• Computational Biology methods   MeSH
• Publication type
• Journal Article MeSH