Details for Diana Naalden

Researchgroup Applied Molecular Genetics
Function PhD student
Phone +32-9-2646234
Office Block B, room 120.012
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Functional analysis of Meloidogyne graminicola effectors

Plant parasitic nematodes are important pests of plants, resulting worldwide in dramatic crop yield losses. The root-knot nematode Meloidogyne graminicola is known as an important pathogen of rice and with the increased interest in aerobic rice cultivation, this nematode may become a serious threat.

The interaction between sedentary plant nematodes and their host plant is a fascinating study object, as the nematodes developed complex strategies to infect the roots. M. graminicola enters as a free-living juvenile rice plants, to search for a suitable cell close to the vascular cylinder of the roots. While invading the plant roots the nematodes secrete effectors, which are essential for successful parasitism. Effectors may function in the re-differentiation of root cells to a feeding site or may play a role in the suppression of the immune system of the plant.

Recently, potential novel effectors of M. graminicola were identified using 454 sequencing technology. The goal of this PhD project is to functionally analyze these effectors to understand more on how the nematode is able to invade and survive in the roots.

To obtain more insight in the rice-nematode interaction we use several techniques. To investigate the role of the effector in parasitism we use RNAi to knock down the expression in the gland of the nematode. The expression of the effector is measured by qPCR. We use the yeast two-hybrid system and Bimolecular Fluorescence Complementation to identify potential target plant proteins of the effector. To determine the localization of the effector in the plant cell we use fluorescence microscopy. The effect of overexpression of the effector on cell regulation is further investigated by rice transformations and pathogen infection assays. We investigate if the effector has a role in immune suppression using plant defense suppression assays.