Molecular Characterization of A Novel Effector Expansin-like Protein from Heterodera avenae that Induces Cell Death in Nicotiana benthamiana.
Cereal cyst nematodes are sedentary biotrophic endoparasites that maintain a complex interaction with their host plants. Nematode effector proteins are synthesized in the oesophageal glands and are secreted into plant tissues through the stylet. To understand the function of nematode effectors in parasitic plants, we cloned predicted effectors genes from Heterodera avenae and transiently expressed them in Nicotiana benthamiana. Infiltration assays showed that HaEXPB2, a predicted expansin-like protein, caused cell death in N. benthamiana. In situ hybridization showed that HaEXPB2 transcripts were localised within the subventral gland cells of the pre-parasitic second-stage nematode. HaEXPB2 had the highest expression levels in parasitic second-stage juveniles. Subcellular localization assays revealed that HaEXPB2 could be localized in the plant cell wall after H. avenae infection.This The cell wall localization was likely affected by its N-terminal and C-terminal regions. In addition, we found that HaEXPB2 bound to cellulose and its carbohydrate-binding domain was required for this binding. The infectivity of H. avenae was significantly reduced when HaEXPB2 was knocked down by RNA interference in vitro. This study indicates that HaEXPB2 may play an important role in the parasitism of H. avenae through targeting the host cell wall.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.|Key Laboratory of Plant Pathology of Ministry of Agriculture, College of Plant Protection, China Agricultural University, Beijing 100193, China.
Jing
J
Liu
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Huan
H
Peng
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Jiangkuan
J
Cui
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Wenkun
W
Huang
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Lingan
L
Kong
Plant Health and Biotechnology Division, Norwegian Institute of Bioeconomy Research, Høgskoleveien 7, 1430 Ås, Norway.
Jihong Liu
JL
Clarke
Key Laboratory of Plant Pathology of Ministry of Agriculture, College of Plant Protection, China Agricultural University, Beijing 100193, China.
Heng
H
Jian
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.|Department of Plant Pathology, Ohio State University, Columbus, OH 43210, USA.
Guo Liang
GL
Wang
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Deliang
D
Peng
D000818:Animals; D016923:Cell Death / Q000235:genetics; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism*; D010935:Plant Diseases / Q000469:parasitology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014026:Nicotiana / Q000378:metabolism*; D014431:Tylenchoidea / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity
D015801:Helminth Proteins; D034741:RNA, Small Interfering; D011956:Receptors, Cell Surface; C055213:saccharide-binding proteins; D002482:Cellulose