Research Applied Molecular Genetics

The research in the group of Lieve Gheysen is focused on the one hand on the molecular analysis of the interactions between plants and pests/pathogens and on the other hand on biotechnology applications and communication.


1. The molecular analysis of plant-nematode interactions with the focus on rice as a host plant

Scientists involved on rice

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Scientists working on other crops


Collaboration with Prof. D. Dewaele (KuLeuven), Prof. Dr. Tina Kyndt and Prof. Dr. Monica Höfte (Ghent University), Dr. Adam Price (University of Aberdeen), Dr. Danny Coyne (IITA, Nairobi) and Dr. D. Fernandez (IRD, Montpellier), Dr. John Jones (JHI, Dundee)


Rice cultivation and nematode problems

Rice production consumes about 30% of freshwater worldwide. To safeguard food security and preserve water resources, exploring ways to reduce water use and increase water-use efficiency in rice production is of critical importance. Aerobic rice is defined as high-yielding rice grown under nonflooded conditions in aerobic soil. Aerobic rice yields over 6 ton/ha were only realized in the first year of cultivation in Asia, after which a rapid and unexplained yield decline took place under continuous cultivation. The causes of yield decline in continuous aerobic rice remain unclear, but this so-called “soil sickness” may be related to the build-up of nematodes or soil pathogens. In field trials with aerobic rice in the Philippines, the root knot nematode Meloidogyne graminicola was identified as a potential threat, especially in light, sandy soils. In this perspective, it is very important to understand the defense responses in rice towards nematodes.

Rice is also a good host for several other nematodes with very different life styles, this makes it interesting to compare how they do this and how the plant reacts to this. Therefore, next to M. graminicola, we are also studying the following nematodes:

  • the rice root rot nematode Hirschmanniella oryzae, an endoparasitic migratory nematode
  • the rice cyst nematode Heterodera schachtii, an endoparasitic sedentary nematode
  • the stem nematode Ditylenchus angustus which is a migratory nematode parasitizing the rice shoots.

Molecular analysis of the nematode signals and of the plant response

The rice-Meloidogyne graminicola interaction is being used to study the role of plant hormones in this interaction. Rootknot nematodes (Meloidogyne) enter the roots, carefully migrate in between the cells and establish half a dozen of giant cells in the vascular tissue. With initiation of this feeding site, the nematodes become sedentary and lose their muscles. To have a more comprehensive view of the plant hormone signalling after nematode infection and to get insight into how these pathways are protecting the plant, several analyses are being performed on infected rice plants. We are also studying why some rice species or cultivars are resistant to M. graminicola, for instance the African rice Oryza glaberrima.


nematode-in-wortel

On the other side of the interaction, the signals secreted by the nematodes are being unravelled. Plant parasitic nematodes secrete hundreds of proteins, called effectors, that facilitate migration through the plant root, induce the feeding sites (in the case of sedentary nematodes) and suppress the plant defense response. RNAi can be used to inactivate nematode genes, not only for functional analysis in research, but also to render the plant less susceptible to nematode attack.




Finding solutions for nematode problems in rice and other crops in Africa

The importance of rice as a food crop in Africa is increasing. Therefore surveys are being performed in Africa (Kenya, Tanzania) to evaluate possible nematode problems in rice cultivation. Nematodes are often hidden enemies of crop production causing substantial yield losses, but with disease symptoms that go unnoticed or are attributed to abiotic stress factors. It would be ideal if we could couple the knowledge obtained on the plant response (see above) with tools to enhance the immune response of the plant. Certain endophytes have been found to stimulate plant growth and plant defense and this strategy is worthwhile to investigate further to protect crops in Africa against nematodes. This stimulation of plant defense has been named priming and can also be triggered by certain chemicals (see also Prof. dr. Tina Kyndt of this department).


For publications see Biblio Godelieve Gheysen



2. Plant biotechnology applications, regulation and communication


Transgenic or cisgenic plants with resistance to pests and pathogens

Besides plant-nematode interactions, other plant-pathogen or -pest interactions are also research topics, but then mainly to use genetic engineering (GMO technology) as a tool to enhance plant resistance to these problems.

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Sweet potato, a naturally transgenic crop



PNAS Cover

In the search for viral sequences in sweet potato, it was discovered that sweet potato naturally contains T-DNA sequences from Agrobacterium, the bacterium that has been used since the 80’s of last century to develop GMO’s. This is the PhD research of Dora Quispe in collaboration with dr. Jan Kreuze from CIP Lima. See the PNAS website for the full article and Science News for a more popular article.

Horizontal gene transfer bringing bacterial DNA into plants never appeared so prominent before as a natural phenomenon putting the whole discussion about GMOs in a different light, in view of the ethical as well as the regulatory aspects.


Biotechnology communication and biosafety regulations

Communication and education on GMOs is the PhD research topic of Jasmien Maes in collaboration with Prof. dr. Martin Valcke while Bhagirath Choudhary and Piet van der Meer do research on biosafety regulation with a focus on India and Europe respectively.

In collaboration with prof. dr. Stijn Speelman, PhD student Edouard Idrissa analyses the relationship between farming systems and the socio-economic impact and conditions of agricultural biotechnology applications in Africa.







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