Systemic resistance induced by volatile organic compounds emitted by plant growth-promoting fungi in Arabidopsis thaliana.
Volatile organic compounds (VOC) were extracted and identified from plant growth-promoting fungi (PGPF), Phoma sp., Cladosporium sp. and Ampelomyces sp., using gas chromatography-mass spectrometry (GC-MS). Among the three VOC extracted, two VOC blends (emitted from Ampelomyces sp. and Cladosporium sp.) significantly reduced disease severity in Arabidopsis plants against Pseudomonas syringae pv. tomato DC3000 (Pst). Subsequently, m-cresol and methyl benzoate (MeBA) were identified as major active volatile compounds from Ampelomyces sp. and Cladosporium sp., respectively, and found to elicit induced systemic resistance (ISR) against the pathogen. Molecular signaling for disease suppression by the VOC were investigated by treating different mutants and transgenic Arabidopsis plants impaired in salicylic acid (SA) or Jasmonic acid (JA)/ethylene (ET) signaling pathways with m-cresol and MeBA followed by challenge inoculation with Pst. Results show that the level of protection was significantly lower when JA/ET-impaired mutants were treated with MeBA, and in SA-, and JA/ET-disrupted mutants after m-cresol treatment, indicating the involvement of these signal transduction pathways in the ISR primed by the volatiles. Analysis of defense-related genes by real-time qRT-PCR showed that both the SA-and JA-signaling pathways combine in the m-cresol signaling of ISR, whereas MeBA is mainly involved in the JA-signaling pathway with partial recruitment of SA-signals. The ET-signaling pathway was not employed in ISR by the volatiles. Therefore, this study identified two novel volatile components capable of eliciting ISR that may be promising candidates in biological control strategy to protect plants from diseases.
The United Graduate School of Agricultural Sciences, Gifu University, Gifu City, Japan.
Hushna Ara
HA
Naznin
Laboratory of Plant Pathology, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Japan.
Daigo
D
Kiyohara
Laboratory of Plant Pathology, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Japan.
Minako
M
Kimura
Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University, Higashiosaka-shi, Osaka, Japan.
Mitsuo
M
Miyazawa
Laboratory of Plant Pathology, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Japan.
Masafumi
M
Shimizu
Laboratory of Plant Pathology, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Japan.
Mitsuro
M
Hyakumachi
D000704:Analysis of Variance; D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D001203:Ascomycota / Q000737:chemistry*; D001565:Benzoates; D003408:Cresols; D003517:Cyclopentanes / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004351:Drug Resistance / Q000187:drug effects; D005030:Ethylenes / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology* / Q000517:prevention & control*; D030821:Plants, Genetically Modified; D044224:Pseudomonas syringae / Q000187:drug effects; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000494:pharmacology*
D001565:Benzoates; D003408:Cresols; D003517:Cyclopentanes; D017931:DNA Primers; D005030:Ethylenes; D054883:Oxylipins; D055549:Volatile Organic Compounds; C032538:4-cresol; C044605:methyl benzoate; C011006:jasmonic acid; C036216:ethylene