Objectif
Nematodes are one of the most important groups of plant parasites and cause significant crop losses world-wide. The objectives of the proposed programme are to gain insight into the molecular mechanisms underlying the pathogenesis and to develop gene constructs that will protect crop plants against these pests. The programme deliverables will be a set of genes tested for their anti-nematode effect, suitable promoters to drive genes active against nematodes and a fuller understanding of plant-nematode interactions. Sedentary nematodes induce re-differentiation of root cells into a permanent nematode feeding site (NFS) that nourishes the developing nematode. Recent data strongly suggest that the glycoproteins secrete from the nematodes sub ventral glands initiate this process but little information is available about how these proteins govern the development of the feeding site. Even more enigmatic is the actual signal transductio pathway from the nematode signal to activation of the plant genes that are involved in induction of the nematode feeding sites. Possibly, one or more nematode secretory proteins interact with plant regulatory proteins o directly with the DNA and in this way initiate a cascade of altered gen expression. The secretory proteins will be characterised using antibodies and their function in plant pathogenesis will be determined. Several gene have recently been shown to be induced in the NFS but their role i induction or maintenance of the feeding site remains to be proven.
Nematode responsive promoters will be cloned and a molecular dissection will identify specific regulatory elements that are responsible for expression in the nematode feeding site. These elements will then be use to construct more specific promoters. The role of the genes that are highly expressed in the feeding sites will be studied by sense an antisense experiments and several different approaches will be used t identify more genes that are induced in the early steps of feeding sit formation. Combining these results will lead to a comprehensive understanding of the molecular mechanisms that underlie the ability o sedentary nematodes to modify plant gene expression. This fundamentally interesting research has important applied consequences: inhibition of NF formation renders the plant resistant to nematode infection. Research will also be carried out to identify proteins and peptides that are toxic o inhibitory to nematode behaviour, feeding and development. Promoter identified from nematode responsive genes will then be coupled t anti-nematode genes for local expression of "resistance" constructs at th site of infection, or they will be used to locally express RNAs (e.g.
antisense) or proteins that are inhibitory for nematode feeding site formation. It is believed that these approaches will be successful in developing plants that are genetically resistant to nematodes, ecologically and economically the only acceptable alternative to the present use of the toxic nematicides.
Champ scientifique
Appel à propositions
Data not availableRégime de financement
CSC - Cost-sharing contractsCoordinateur
9000 GENT
Belgique