Plant Pathology and Microbiology
Journal or Book Title
Molecular Plant Pathology
Cyst nematodes are plant pathogens that infect a wide range of economically important crops. One parasitic mechanism employed by cyst nematodes is the production and in planta delivery of effector proteins to modify plant cells and suppress defenses to favor parasitism. This study focused on GLAND4, an effector of Heterodera glycines and H. schachtii, the soybean and sugar beet cyst nematodes, respectively. We showed that GLAND4 is recognized by the plant cellular machinery and is transported to the plant nucleus, an organelle where little is known about plant nematode effector functions. We showed that GLAND4 has DNA-binding ability and repressed reporter gene expression in a plant transcriptional assay. One DNA-fragment that bound to GLAND4 was localized in an Arabidopsis chromosomal region associated with the promoters of two lipid transfer protein (LTP) genes. These LTPs have known defense functions and are downregulated in the nematode feeding site. When expressed in Arabidopsis, the presence of GLAND4 caused downregulation of the two LTP genes in question, which was associated also with increased susceptibility to the plant-pathogenic bacterium Pseudomonas syringae. Furthermore, overexpression of one of the LTP genes reduced plant susceptibility to H. schachtii and P. syringae, confirming that LTP repression likely suppresses plant defenses. This study made GLAND4 one of a small subset of characterized plant nematode nuclear effectors and identified GLAND4 as the first DNA-binding plantparasitic nematode effector.
BSPP and John Wiley & Sons Ltd
Barnes, Stacey N.; Wram, Catherine L.; Mitchum, Melissa G.; and Baum, Thomas J., "The plant‐parasitic cyst nematode effector GLAND4 is a DNA‐binding protein" (2018). Plant Pathology and Microbiology Publications. 281.