Research conducted by the Laboratory of Nematology is part of the research program of the Graduate School Experimental Plant Sciences (EPS) and the C.T. de Wit Graduate School for Production Ecology & Resource Conservation (PE&RC).
Hormones and nematode feeding site development
Hormones play a crucial role as signalling molecules in multicellular organisms and lay the basis for communication and development of tissue. Due to their wide variety of functions and interactions with cellular mechanisms they become a likely target for manipulation by parasitic agents. Both parasitic cyst and root knot nematodes induce aberrant hormone expression in the feeding sites they establish.
Cyst nematodes initiate the formation of a so called syncytia in the roots of a large variety of plants. The establishment of this syncytial feeding site is done through injection of effector proteins inside a single plant cell. Subsequently the cell walls of the initial and surrounding cells start to dissolve which leads to the fusion of the plasma membranes into an large cellular amalgamation. In contrast, root knot nematodes inject several cells in their surroundings with effector proteins to initiate the formation of giant cells. These cells swell to several times their original size and serve just like the syncytium as a nutrient sink for the nematode to tap into.
These processes of feeding site development are paired with the accumulation of the phytohormone auxin. Auxin is considered the most important growth hormone in plants and its agglomeration is likely mediated through manipulation of the PIN efflux and LAX influx carriers. In addition to auxin the hormone cytokinin seems to be active during the feeding site development. Auxin and cytokinin are classically known to have an antagonistic relationship and the presence of both indicates a functional role for the intricate interplay between the two in nematode feeding site development.
The aim of this project is to unravel the precise molecular mechanisms by which auxin and cytokinin contribute to establishing and maintaining the feeding sites of both cyst and root knot nematodes.