Dataset Information

Olfactory Cues from Pathogenic Fungus Affect the Direction of Motion of Termites, Coptotermes formosanus.

ABSTRACT: Formosan subterranean termites, Coptotermes formosanus, tend to avoid pathogen odors when tested in Y-tube olfactometers, but approach and groom exposed nestmates to remove pathogens from their cuticle and maintain a healthy population. To better understand their differential reaction to pathogens and their odors, the relationship between odor cues and direction of motion was examined with the fungus Isaria fumosorosea K3 strain. The results indicate that nestmate odor was strongly attractive only in tests where fungal odors were present in both branches of the olfactometer. Termites generally avoid fungal odors when offered a choice without fungal odor. We also tested termite aversion to 3-octanone and 1-octen-3-ol, major surface chemical compounds of I. fumosorosea K3, and estimated the total mass of these compounds present on the conidial surface by direct extraction method. The total quantity of these chemicals on the surface of fungal conidia was estimated to be approximately 0.01 ng per 10(7) conidia. This study demonstrates a context dependent behavioral change in termites in response to the odors of pathogenic fungi.

SUBMITTER: Yanagawa A

PROVIDER: S-EPMC4675792 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The survival and foraging of Coptotermesformosanus Shiraki in a microbe-rich environment reflect the adaptation of an extraordinary, sophisticated defense mechanism by the nest-mates. We aimed to explore the host pathogen interaction by studying caste-specific volatile chemistry and genes encoding the antioxidant defense of winged imagoes, nymphs, soldiers and workers of Formosan subterranean termites. Qualitative analyses of C.formosanus Shiraki performed by HS-SPME/GC-MS showed considerable variations in the chemical composition of volatile organic compounds (VOCs) and their proportions among all the castes. Winged imagoes produced the most important compounds such as naphthalene and n-hexanoic acid. The antifungal activity of these compounds along with nonanal, n-pentadecane, n-tetradecane, n-heptadecane and methyl octanoate against the conidial suspensions of Metarhiziumanisopliae and Beauveriabassiana isolates enable us to suggest that the failure of natural fungal infection in the nest is due to the antiseptic environment of the nest, which is mainly controlled by the VOCs of nest-mates. In addition, conidial germination of M.anisopliae and B.bassiana isolates evaluated on the cuticle of each caste showed significant variations among isolates and different castes. Our results showed that the conidia of M.anisopliae 02049 exhibited the highest germination on the cuticle of all the inoculated castes. Moreover, we recorded the lowest germination of the conidia of B.bassiana 200436. Caste-specific germination variations enabled us to report for the first time that the cuticle of winged imagoes was found to be the most resistant cuticle. The analysis of the transcriptome of C.formosanus Shiraki revealed the identification of 17 genes directly involved in antioxidant defense. Expression patterns of the identified antioxidant genes by quantitative real-time PCR (qPCR) revealed the significantly highest upregulation of CAT, GST, PRXSL, Cu/Zn-SOD2, TXN1, TXN2, TXNL1, TXNL2, TXNL4A and TPx genes among winged imagoes upon infection with the most virulent isolate, M.anisopliae 02049. Furthermore, soldiers showed the least expression of genes encoding antioxidant defense. Our findings indicated that the volatile chemistry of nest-mates and genes encoding antioxidant defense greatly contribute to the survival and foraging of Formosan subterranean termites in a microbe-rich habitat.

Dataset Information

Olfactory Cues from Pathogenic Fungus Affect the Direction of Motion of Termites, Coptotermes formosanus.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets