An Efficient cDNA-AFLP-Based Strategy for the Identification of Putative Pathogenicity Factors from the Potato Cyst Nematode Globodera rostochiensis

Abstract

A new strategy has been designed to identify putative pathogenicity factors from the dorsal or subventral esophageal glands of the potato cyst nematode Globodera rostochiensis. Three independent criteria were used for selection. First, genes of interest should predominantly be expressed in infective second-stage juveniles, and not, or to a far lesser extent, in younger developmental stages. For this, gene expression profiles from five different developmental stages were generated with cDNA-AFLP (amplified fragment length polymorphism). Secondly, the mRNA corresponding to such a putative pathogenicity factor should predominantly be present in the esophageal glands of pre-parasitic juveniles. This was checked by in situ hybridization. As a third criterion, these proteinaceous factors should be preceded by a signal peptide for secretion. Expression profiles of more than 4,000 genes were generated and three up-regulated, dorsal gland-specific proteins preceded by signal peptide for secretion were identified. No dorsal gland genes have been cloned before from plant-parasitic nematodes. The partial sequence of these three factors, A4, A18, and A41, showed no significant homology to any known gene. Their presence in the dorsal glands of infective juveniles suggests that these proteins could be involved in feeding cell initiation, and not in migration in the plant root or in protection against plant defense responses. Finally, the applicability of this new strategy in other plant-microbe interactions is discussed.

Dual disease resistance mediated by the immune receptor Cf-2 in tomato requires a common virulence target of a fungus and a nematode

“…A fragment of 176 base pairs derived from the Gr-VAP1 transcript was identified in a cDNA-AFLP analysis of successive developmental stages of G. rostochiensis pathotype Ro1 Mierenbos (23). The transcript-derived fragment was extended using partially overlapping expressed sequence tags of G. rostochiensis in a nonredundant database (40).…”

“…The expression of effectors in the potato cyst nematode G. rostochiensis is turned on when the obligate dormant period ends and the nematode begins to hatch from eggs in the soil. To identify effectors of G. rostochiensis, we conducted a cDNA-amplified fragment length polymorphism (AFLP)-based transcriptome analysis during this transition in metabolic activity of the nematodes (23). Our analysis revealed, among others, a transcript-derived fragment of 176 base pairs named NC4, which was strongly up-regulated in infective juveniles (Fig.…”

Cellulose Binding Protein from the Parasitic Nematode Heterodera schachtii Interacts with Arabidopsis Pectin Methylesterase: Cooperative Cell Wall Modification during Parasitism

“…The parasitic feats of cyst nematodes during penetration, migration, syncytium formation and maintenance, and feeding are aided by proteinaceous stylet secretions, which are the expression products of specific parasitism genes in nematode esophageal gland cells (Davis et al, , 2008. Parasitism proteins are synthesized as preproteins with N-terminal signal peptides targeting them to the gland cell endoplasmic reticulum and the secretory pathway (Qin et al, 2000;Wang et al, 2001). Nematode parasitism proteins are developmentally produced and released through the stylet into plant tissues and cells to promote the parasitic interaction.…”

Sinorhizobium meliloti nifA mutant induces different gene expression profile from wild type in Alfalfa nodules

“…Since its first application on potato tuber development, several modifications of this technique have improved its validity and advantages over other fingerprinting techniques and DNA chip-based approaches [18][19][20]. In most cases, it has been employed for surveying transcriptional changes in host plants during interactions with fungi, bacteria, nematode or environmental stimuli [21][22][23][24][25][26][27][28][29]. In this study, cDNA-AFLP was successfully used to identify 37 differentially expressed host plant genes in Alfalfa nodules.…”