Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile terpenes, induced by the infection of Xoo, and investigated their biological roles in the rice plant. Monoterpenes α-thujene, α-pinene, sabinene, myrcene, α-terpene, and (S)-limonene and sesquiterpenes cyclosativene, α-copaene, and β-elemene were detected from 1-week-old Xoo-infected rice seedlings, by solid-phase microextraction-gas chromatography-mass spectrometry. All monoterpenes were constitutively released from rice seedlings before Xoo infection. However, (S)-limonene emission was further elicited after exposure of the seedlings to Xoo in coincidence with upregulation of limonene synthase gene (OsTPS20) transcripts. Only the stereospecific (S)-limonene [and not (R)-limonene or other monoterpenes] severely inhibited Xoo growth, as confirmed by disc diffusion and liquid culture assays. Rice seedlings showed suppressed pathogenic symptoms suggestive of resistance to Xoo infection after foliar treatment with (S)-limonene. Collectively, our findings suggest that (S)-limonene is a volatile phytoanticipin, which plays a significant role in suppressing Xoo growth in rice seedlings.
Gruppo in fibra SPME divinilbenzene/carbossene/polidimetilsilossano (DVB/CAR/PDMS), matrix active group 50/30µm DVB/CAR/PDMS, needle size 24 ga, StableFlex fiber, for use with autosampler, fiber L 2 cm, pk of 3
Gruppo in fibra SPME divinilbenzene/carbossene/polidimetilsilossano (DVB/CAR/PDMS), matrix active group 50/30µm DVB/CAR/PDMS, StableFlex fiber, manual holder, needle size 24 ga
Gruppo in fibra SPME divinilbenzene/carbossene/polidimetilsilossano (DVB/CAR/PDMS), matrix active group 50/30µm DVB/CAR/PDMS, needle size 24 ga, StableFlex, for use with autosampler, fiber L 1 cm, pk of 3
Gruppo in fibra SPME divinilbenzene/carbossene/polidimetilsilossano (DVB/CAR/PDMS), for use with autosampler, matrix active group 50/30µm DVB/CAR/PDMS, needle size 23 ga, metal alloy fiber, fiber L 2 cm