France
September 29, 2010
Researchers have sequenced and characterized the AtMAP65-3 gene, coding for a Microtubule Associated Protein of the MAP65 family in A. thaliana. By the use of gene silencing RNA interference method, researchers have demonstrated that the down-regulation of AtMAP65-3 gene decreases the sensitivity of transgenic A. thaliana plant to the root-knot nematode. This novel approach can successfully be applied by breeders of vegetables, cereals, fruits, flowers and woody plants, in order to search for MAP65-3 orthologue genes in other species, produce defective MAP65-3 by various techniques (mutagenesis, TILLING, K-O, gene silencing, etc.), and develop new nematode-resistant varieties.
Damages caused by nematodes lead to qualitative and quantitative harvest losses in many crops. After penetrating the plant, sedentary endoparasitic nematodes use the plant cells in order to create a new cluster of cells which is required for their growth and their reproduction: the feeding cells.
A strategy for combating these endoparasitic nematodes consists in inhibiting the formation of feeding cells, by exploiting an understanding of the molecular mechanisms involved.
Within the framework of the GENOPLANTE program, researchers screened 20,000 T-DNA tagged Arabidopsis lines in a GUS promoter trap strategy experiment to isolate genes involved in giant cell formation in response to Meloidogyne incognita infection. One of these lines showed early GUS activity in galls with clear activity within 48 hours after giant cell initiation. GUS activity was observed during the giant cell maturation phase in the developing and surrounding dividing cells up to 14 days after infection. After this period, mature galls were formed and GUS activity was observed in the surrounding cells but not in the mature giant cells.
Researchers have sequenced and characterized the AtMAP65-3 gene, coding for a Microtubule Associated Protein of the MAP65 family in A. thaliana. AtMAP65-3 is expressed at early stages of nematode-induced feeding site formation. In the absence of functional AtMAP65-3, feeding cells develop but fail to fully differentiate and are eventually destroyed, resulting in incomplete development of the root-knot nematode and its death. By the use of gene silencing RNA interference method, researchers have demonstrated that the down-regulation of AtMAP65-3 gene decreases the sensitivity of transgenic A. thaliana plant to the root-knot nematode.
AtMAP65-3 is an essential host susceptibility gene, playing a critical role in plant-nematode interaction by its requirement for giant cell ontogenesis.
Potential industrial application
In contrast to traditional methods for improving plant resistance to pathogens, decreasing plant sensitivity to endoparasitic nematodes would limit the possibility for pests to overcome this resistance. This novel approach can successfully be applied by breeders of vegetables, cereals, fruits, flowers and woody plants, in order to search for MAP65-3 orthologue genes in other species, produce defective MAP65-3 by various techniques (mutagenesis, TILLING, K-O, gene silencing, etc.), and develop new nematode-resistant varieties.
The isolated promoter is an ideal tool to control gene expression in response to nematode infection during the giant cell initiation and maturation phases. The use of this promoter will enable expression of sequences to counter nematode infection, to produce in an infection responsive fashion either RNAi or proteins with nematicidal activity.
Heading : Plant Biotechnology, Plant Genetic and Improvment, Plant Health
Intellectual property : Patent
Patent application number :
Demande internationale de brevet WO2008/139334
Laboratory/Team :
UMR 1301 Interactions Biotiques et Santé Végétale
INRA, 400 route des Chappes
06903 Sophia Antipolis
France.
Scientific leader:
Bruno FAVERY
Business manager :
Claire LEMONTEY
INRA Transfert
28 rue du Docteur Finlay,
75015 Paris,
France
Phone: +33 (0) 1 42 75 92 96
Email: claire.lemontey@paris.inra.fr
Species
