Heterodera zeae, the corn cyst nematode, is redescribed and illustrated with comparative details and measurements of females, cysts, and larvae from Maryland, USA; and India. Scanning electron micrographs o f specimens from the United States are also presented. Revised measurements for the larval stylet and new diadnostic characters, especially in the cyst cone, for H. zeae are given. The relat...

The molecular mechanisms regulating the accuracy of gene expression are still not fully understood. Among these mechanisms, Nonsense-mediated Decay (NMD) is a quality control process that detects post-transcriptionally abnormal transcripts and leads them to degradation. The UPF1 protein lays at the heart of NMD as shown by several structural and functional features reported for this factor main...

A survey of plant parasitic nematodes associated with Zea mays in Kashmir valley was conducted from June 2006 to November 2006 which yielded a number of Tylenchids. Among them, the species Tylenchorhynchus zeae Sethi and G. Swarp, 1968, Pratylenchus sativus kaul, 1985, Aphelenchoides srinagrensisKaul, 1985 are reported herein, with dimensions. The parasites are being recorded for the first time...

Ustilago maydis is a fungal pathogen of maize. Some strains of U. maydis encode secreted polypeptide toxins capable of killing other susceptible strains of U. maydis. We show here that one of these toxins, the KP6 killer toxin, is synthesized by transgenic tobacco plants containing the viral toxin cDNA under the control of a cauliflower mosaic virus promoter. The two components of the KP6 toxin...

Cyclin-dependent kinases from the Cdk5/Pho85 family are thought to play important roles in morphogenesis in species as diverse as yeast and humans. In the phytopathogenic fungus Ustilago maydis Cdk5 has a major role in the maintenance of cell polarity and virulence. This role seems to be related to the ability of the guanine-nucleotide exchange factor (GEF) Cdc24 to localize at the cell tips. H...

In the phytopathogenic fungus Ustilago maydis, cell fusion is governed by a pheromone signalling system. The pheromone receptors belong to the seven transmembrane class that are coupled to heterotrimeric G proteins. We have isolated four genes (gpa1 to gpa4) encoding alpha subunits of G proteins. Gpa1, Gpa2 and Gpa3 have homologues in other fungal species, while Gpa4 is novel. Null mutants in i...

During induction of the virulence program in the phytopathogenic fungus Ustilago maydis, the cell cycle is arrested on the plant surface and it is not resumed until the fungus enters the plant. The mechanism of this cell cycle arrest is unknown, but it is thought that it is necessary for the correct implementation of the virulence program. Here, we show that this arrest takes place in the G2 ph...

Correspondence analyses were used to explore the relationships between yield and populations of Pratylenchus zeae in an upland rice field and in a greenhouse experiment. Initial soil (Pi) and final root (Pf) population densities of P. zeae, and yield (Y) of rice cv. UPL Ri5 were determined at 490 spots in the field. Very low Y was linked to very high Pf. Low Y was linked to medium or high Pi an...

Fusarium graminearum (teleomorph Gibberella zeae) is a significant pathogen of wheat and corn. F. graminearum forms multicellular macroconidia that play an important role in dissemination of the disease. The spatial pattern of morphogenesis in germinating macroconidia is described. Germ tubes preferentially emerge from the apical cells in a bipolar pattern that appears to be common to filamento...

Dickeya zeae is a phytopathogenic bacterium causing soft rot diseases in a wide range of economically important crops. Here we present the draft genome sequence of strain ZJU1202, which is the causal agent of rice foot rot in China. The draft genome will contribute to epidemiological and comparative genomic studies and the quarantine of this devastating phytopathogen.