Application of Microarray Technology in Plant Nematology

During a compatible interaction, root-knot nematodes (Meloidogyne spp.) induce the root cells dedifferentiation into multinucleate feeding cells, known as giant cells. Hyperplasia and hypertrophy of the cells surrounding the head of nematode lead to the formation of a root gall. Different studies showed that the transformation of root cells into hypertrophied feeding structures, with unique morphology and functions, require some changes in the expression of a large number of genes. Previous approaches, based on differential gene expression between healthy and infected plants, analyses of known candidate genes by promoter GUS fusion or in situ hybridization and promoter trap strategies, have resulted in the characterization of about 50 genes of plant that are up regulated and 10 genes that are down regulated in giant cells. Microarray technology makes it possible to generate large-scale information about patterns of gene expression during plant–nematode interactions. A DNA microarray is a collection of microscopic DNA spots attached to a solid surface. Each DNA spot contains 10−12 moles of a specific DNA sequence, which are known as probes. These can be a short section of a gene or other DNA element that are used to hybridize a cDNA or cRNA sample that called as target. Probe-target hybridization is usually detected by detection of fluorophore or silver labeled targets.