Weak photon emission from the Japanese black pine inoculated with pine wood nematode

Abstract

The weak photon emission from Japanese black pine inoculated with pine wood nematodes were characterized. The first peak of photon emission appeared within 30 min after inoculation with nematodes, and the second peak was observed about 70 hr after inoculation. The first photon emission lasted for 1 hr, but the second emission lasted over 100 hr longer. Although treatment with dead nematodes and with supernatant of nematode-suspended water both induced the first peak, the second peak was not detected after either of these treatments. Loblolly pine (resistant host plant) inoculated with nematodes emitted the same pattern of photons as that of Japanese black pine (susceptible host plant), although the intensity of emission from Loblolly pine was weaker than that of Japanese black pine. However, photon emission from the inoculated Japanese cedar (nonhost plant) did not increase. From these results, the first and second peaks seem to be related to substance(s) originating from the nematodes and from cell damage caused by nematodes, respectively.