With a diverse host range, Meloidogyne incognita (root-knot nematode) is listed as one of the most economically important obligate parasites of agriculture. This nematode species establishes permanent feeding sites in plant root systems soon after infestation. A compatible host-nematode interaction triggers a cascade of morphological and physiological process disruptions of the host, leading to pathogenesis. Such disruption is reflected by altered gene expression in affected cells, detectable using molecular approaches. We employed a high-throughput proteomics approach to elucidate the events involved in a compatible banana- M. incognita interaction. This study serves as the first crucial step in developing natural banana resistance for the purpose of biological-based nematode management programme. We successfully profiled 114 Grand naine root proteins involved in the interaction with M. incognita at the 30th- and 60th- day after inoculation (dai). The abundance of proteins involved in fundamental biological processes, cellular component organisation and stress responses were significantly altered in inoculated root samples. In addition, the abundance of proteins in pathways associated with defence and giant cell maintenance in plants such as phenylpropanoid biosynthesis, glycolysis and citrate cycle were also implicated by the infestation.
A nematode population distribution survey was conducted in banana plantations/farms in Peninsular Malaysia from June 2004 to January 2006. This study highlights differences obtained from the survey compared with previously published reports in terms of species prevalence in banana plantations. As opposed to the widely reported prevalence of Radopholus similis (Cobb 1893) Thorne, 1949, on banana plants worldwide, Rotylenchulus reniformis Linford and Oliveira, 1940, was found to be the most common nematode species in the isolated soil samples (Prominence Value = 824.28; n=63) while Meloidogyne incognita (Kofoid & White 1919) Chitwood, 1949, was predominant in the isolated root samples (Prominence Value = 449.77; n=57) in Peninsular Malaysia. Besides, contradicting previous reports, M. incognita was found to dominate Cavendish plantation areas in this region instead of R. similis. Inter-species interaction resulting in species predominance and co-dominance in banana rhizosphere was also observed in this study.
We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica.