TY - JOUR
T1 - Systemic defense activation by COS-OGA in rice against root-knot nematodes depends on stimulation of the phenylpropanoid pathway
AU - Singh, Richard Raj
AU - Chinnasri, Buncha
AU - De Smet, Lien
AU - Haeck, Ashley
AU - Demeestere, Kristof
AU - Van Cutsem, Pierre
AU - Van Aubel, Geraldine
AU - Gheysen, Godelieve
AU - Kyndt, Tina
N1 - Funding Information:
We acknowledge the financial support by an Erasmus Mundus Action 2 Lotus III postdoc grant to Buncha Chinnasri, and of the Ghent University Bijzonder OnderzoeksFonds (BOF) through grants ‘GOA-01GB3013’ and a ‘ BOF-starting grant ’ (Tina Kyndt).
Publisher Copyright:
© 2019 Elsevier Masson SAS
PY - 2019/9/1
Y1 - 2019/9/1
N2 - Activation of induced plant resistance to control pests and diseases is regaining attention in the current climate where chemical pesticides are being progressively banned. Formulations of chitosan oligomers (COS) and pectin-derived oligogalacturonides (OGA), COS-OGA, have previously been described to induce resistance against fungal diseases in different crop plants. Here, we investigated their potential and mode-of-action as preventive measures to control root-knot nematode Meloidogyne graminicola infection in rice. The results show a significant reduction in root-galling and nematode development in rice plants that were treated through foliar application with the COS-OGA formulations FytoSol® and FytoSave® 24 h before nematode inoculation. Hormone measurements, gene expression analyses, corroborated by treatments on salicylic acid (SA) and jasmonic acid (JA)-mutants indicated that the systemic COS-OGA induced defense mechanism against nematodes is not based on SA or JA activation. However, phenylalanine ammonia lyase (PAL) gene expression in roots as well as enzymatic PAL activity in the shoots were significantly induced 24 h after foliar COS-OGA spraying in comparison with untreated plants. COS-OGA-induced systemic defense was abolished in the rice OsPAL4-mutant, demonstrating that COS-OGA-induced defense is dependent on OsPAL4 activation in rice plants.
AB - Activation of induced plant resistance to control pests and diseases is regaining attention in the current climate where chemical pesticides are being progressively banned. Formulations of chitosan oligomers (COS) and pectin-derived oligogalacturonides (OGA), COS-OGA, have previously been described to induce resistance against fungal diseases in different crop plants. Here, we investigated their potential and mode-of-action as preventive measures to control root-knot nematode Meloidogyne graminicola infection in rice. The results show a significant reduction in root-galling and nematode development in rice plants that were treated through foliar application with the COS-OGA formulations FytoSol® and FytoSave® 24 h before nematode inoculation. Hormone measurements, gene expression analyses, corroborated by treatments on salicylic acid (SA) and jasmonic acid (JA)-mutants indicated that the systemic COS-OGA induced defense mechanism against nematodes is not based on SA or JA activation. However, phenylalanine ammonia lyase (PAL) gene expression in roots as well as enzymatic PAL activity in the shoots were significantly induced 24 h after foliar COS-OGA spraying in comparison with untreated plants. COS-OGA-induced systemic defense was abolished in the rice OsPAL4-mutant, demonstrating that COS-OGA-induced defense is dependent on OsPAL4 activation in rice plants.
KW - Hormone
KW - Phenylpropanoids
KW - Plant defense elicitor
UR - http://www.scopus.com/inward/record.url?scp=85068552849&partnerID=8YFLogxK
U2 - 10.1016/j.plaphy.2019.07.003
DO - 10.1016/j.plaphy.2019.07.003
M3 - Article
SN - 0981-9428
VL - 142
SP - 202
EP - 210
JO - Plant Physiology and Biochemistry
JF - Plant Physiology and Biochemistry
ER -