OPDA Has Key Role in Regulating Plant Susceptibility to the Root-Knot NematodeMeloidogyne haplainArabidopsis.
Jasmonic acid (JA) is a plant hormone that plays important roles in regulating plant defenses against necrotrophic pathogens and herbivorous insects, but the role of JA in mediating the plant responses to root-knot nematodes has been unclear. Here we show that an application of either methyl jasmonate (MeJA) or the JA-mimic coronatine (COR) onArabidopsissignificantly reduced the number of galls caused by the root-knot nematodeMeloidogyne hapla. Interestingly, the MeJA-induced resistance was independent of the JA-receptor COI1 (CORONATINE INSENSITIVE 1). The MeJA-treated plants accumulated the JA precursorcis-(+)-12-oxo-phytodienoic acid (OPDA) in addition to JA/JA-Isoleucine, indicating a positive feedback loop in JA biosynthesis. Using mutants in the JA-biosynthetic pathway, we found that plants deficient in the biosynthesis of JA and OPDA were hyper-susceptible toM. hapla.However, theopr3mutant, which cannot convert OPDA to JA, exhibited wild-type levels of nematode galling. In addition, mutants in the JA-biosynthesis and perception which lie downstream ofopr3also displayed wild-type levels of galling. The data put OPR3 (OPDA reductase 3) as the branch point between hyper-susceptibility and wild-type like levels of disease. Overall, the data suggests that the JA precursor, OPDA, plays a role in regulating plant defense against nematodes.
Department of Plant Molecular Biology and Physiology, Georg August University - Albrecht von Haller InstituteGöttingen, Germany; Department of Plant Molecular Biology and Physiology, Georg August University - Göttingen Center for Molecular BiosciencesGöttingen, Germany.
Cynthia
C
Gleason
Department of Plant Molecular Biology and Physiology, Georg August University - Albrecht von Haller Institute Göttingen, Germany.
Natthanon
N
Leelarasamee
Department of Plant Biochemistry, Georg August University - Albrecht von Haller Institute Göttingen, Germany.
Dorothea
D
Meldau
Department of Plant Biochemistry, Georg August University - Albrecht von Haller InstituteGöttingen, Germany; Department of Plant Biochemistry, Georg August University - Göttingen Center for Molecular BiosciencesGöttingen, Germany.
Ivo
I
Feussner
COI1; Jasmonic acid; induced resistance; nematodes; opda; plant defense; plant hormones