Spectral Analysis of Ultraweak Chemiluminescence from Kidney Bean Leaf Infested with Tetranychus Kanzawai Kishida

Abstract

We performed the spectral analysis of ultraweak-photon emissions from kidney bean leaves infested by the kanzawa spider mite, Tetranychus kanzawai Kishida (Acari: Tetranychidae). We also measured the spectrum of photon emissions from artificially wounded leaves, and compared the result with spectral data obtained from the mite-infested leaves. Photon emissions from both the mite-infested and wounded leaves primarily consisted of wavelengths ranging from 500 to 700 nm, and photon intensity at these wavelengths increased steadily after perturbation. In contrast, photon intensity of the miteinfested leaves at 300-400 nm exhibited only differential changes; it began increasing at 20 h, and showed two peaks at 72 and 120 h. We previously reported that photon emissions from infested leaves might be the result of both insect damage and plant self-protection. Plant defensive responses, such as herbivore-induced plant volatiles (HIPV), are induced by insect elicitors via insect damage. Therefore, photon intensity at 500-700 nm might be related to direct injury (physiological stress), while photon intensity at 300-400 nm may signify a physiological (biochemical)-action-related defensive response.

Ultraweak photon emission from herbivory-injured maize plants

“…Based on further analyses, Iyozumi et al [7] suggested that spectral shifts in ultraweak photon emissions observed during the defense response may represent a change in the physiological state of the sweet potato connected with the synthesis of defense-related substances. It has also been reported that herbivorous mites have induced ultraweak photon emissions from a kidney bean leaf [8]. By measuring the chlorophyll content in bean leaves, the report demonstrated that the intensity of the photon emissions represents the degree of damage.…”

“…In plants, ultraweak luminescence has been emitted in response to environmental changes and stress, such as temperature changes [15], salt stress [13], drought damage [14], pathogenic fungus attack [10], and herbivorous mite infection [8].…”