Thiamine-induced priming against root-knot nematode infection in rice involves lignification and hydrogen peroxide generation.
Thiamine (vitamin B1, VB1) can act as a plant defence trigger, or priming agent, leading to a rapid counterattack on pathogen invasion. In this study, the priming effect of thiamine on rice (Oryza sativa cv. Nipponbare) and its activity against root-knot nematode (Meloidogyne graminicola) infection were evaluated. Thiamine treatment and subsequent nematode inoculation activated hydrogen peroxide (H2O2) accumulation and lignin deposition in plant roots, and this correlated with enhanced transcription of OsPAL1 and OsC4H, two genes involved in the phenylpropanoid pathway. The number of nematodes in rice roots was slightly but significantly reduced, and the development of the nematodes was delayed, whereas no direct toxic effects of VB1 on nematode viability and infectivity were observed. The combined application of thiamine with l-2-aminooxy-3-phenylpropionic acid (AOPP), an inhibitor of phenylalanine ammonia-lyase (PAL), significantly hampered the VB1-priming capacity. These findings indicate that thiamine-induced priming in rice involves H2O2 and phenylpropanoid-mediated lignin production, which hampers nematode infection. Further cellular and molecular studies on the mechanism of thiamine-induced defence will be useful for the development of novel nematode control strategies.
Department of Molecular Biotechnology, Ghent University, Coupure links 653, Ghent, B-9000, Belgium.|State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Wen-Kun
WK
Huang
Department of Molecular Biotechnology, Ghent University, Coupure links 653, Ghent, B-9000, Belgium.|Institute of Plant Protection, Sichuan Academy of Agricultural Sciences, Jingjusi Road 20, Chengdu, 610066, China.
Hong-Li
HL
Ji
Department of Molecular Biotechnology, Ghent University, Coupure links 653, Ghent, B-9000, Belgium.
Godelieve
G
Gheysen
Department of Molecular Biotechnology, Ghent University, Coupure links 653, Ghent, B-9000, Belgium.
Tina
T
Kyndt
D000818:Animals; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000469:parasitology*; D010935:Plant Diseases / Q000469:parasitology*; D018517:Plant Roots / Q000187:drug effects / Q000469:parasitology*; D010941:Plant Tumors / Q000235:genetics / Q000469:parasitology; D020005:Propanols / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013831:Thiamine / Q000494:pharmacology*; D014431:Tylenchoidea / Q000187:drug effects / Q000472:pathogenicity*
D020005:Propanols; C439395:1-phenylpropanol; D008031:Lignin; D006861:Hydrogen Peroxide; D013831:Thiamine
Meloidogyne graminicola; callose; hydrogen peroxide; induced defence; lignin; priming; thiamine