September, 2006
Source:
Proceedings ot the National
Academy of Sciences of the United States of America
Link:
http://www.pnas.org/cgi/content/abstract/103/39/14302
Engineering broad root-knot
resistance in transgenic plants by RNAi silencing of a conserved
and essential root-knot nematode parasitism gene
Guozhong Huang*, Rex Allen*, Eric L. Davis, Thomas J. Baum,
and Richard S. Hussey*
*Department of Plant Pathology, University of Georgia, Athens,
GA 30602-7274; Department of Plant Pathology, North Carolina
State University, Raleigh, NC 27695-7616; and Department of
Plant Pathology, Iowa State University, Ames, IA 50011
Edited by Maarten J. Chrispeels, University of California at San
Diego, La Jolla, CA, and approved August 8, 2006 (received for
review June 8, 2006)
ABSTRACT
Secreted parasitism proteins
encoded by parasitism genes expressed in esophageal gland cells
mediate infection and parasitism of plants by root-knot
nematodes (RKN). Parasitism gene 16D10 encodes a conserved RKN
secretory peptide that stimulates root growth and functions as a
ligand for a putative plant transcription factor. We used in
vitro and in vivo RNA interference approaches to silence this
parasitism gene in RKN and validate that the parasitism gene has
an essential function in RKN parasitism of plants. Ingestion of
16D10 dsRNA in vitro silenced the target parasitism gene in RKN
and resulted in reduced nematode infectivity. In vivo expression
of 16D10 dsRNA in Arabidopsis resulted in resistance effective
against the four major RKN species. Because no known natural
resistance gene has this wide effective range of RKN resistance,
bioengineering crops expressing dsRNA that silence target RKN
parasitism genes to disrupt the parasitic process represents a
viable and flexible means of developing novel durable
RKN-resistant crops and could provide crops with unprecedented
broad resistance to RKN.
RELATED NEWS ARTICLE FROM
CropBiotech
ENGINEERING ROOT-KNOT RESISTANCE
IN PLANTS
Root-knot nematodes (RKN) are the most economically important
group of plant-parasitic nematodes worldwide, attacking nearly
2000 species of crop and fiber plants. The nematode invades
plant roots, and by feeding on the roots’ cells, they cause the
roots to grow large galls, or knots, damaging the crop and
reducing its yields. Led by professor Richard Hussey,
researchers from the University of Georgia, Iowa State
University, and North Carolina State University engineered
root-knot nematode resistance in transgenic plants by silencing
or ‘knocking out’ an essential gene that causes the nematode to
become parasitic. The result of their study is published in a
recent issue of the Proceedings of the National Academy of
Sciences (PNAS).
The research group described experiments to silence the
parasitism gene 16D10 in root-knot nematode, and they confirm
that the gene is essential for root-knot nematode to exhibit
parasitism. In addition, expression of the same regulator for
16D10 in Arabidopsis resulted in resistance against the four
major RKN species. The results of silencing of parasitism gene
16D10 in RKN could lead to the development of crops with broad
resistance to this destructive pathogen.
Readers can access the full article, “Engineering broad
root-knot resistance in transgenic plants by RNAi silencing of a
conserved and essential root-knot nematode parasitism gene” at
http://www.pnas.org/cgi/content/full/103/39/14302.
For the abstract, visit
http://www.pnas.org/cgi/content/abstract/103/39/14302 |