Next Article in Journal
The Venom of the Spine-Bellied Sea Snake (Hydrophis curtus): Proteome, Toxin Diversity and Intraspecific Variation
Next Article in Special Issue
Transcriptome-Wide Identification and Characterization of Potato Circular RNAs in Response to Pectobacterium carotovorum Subspecies brasiliense Infection
Previous Article in Journal
Analysis and Prediction of Exon Skipping Events from RNA-Seq with Sequence Information Using Rotation Forest
Previous Article in Special Issue
Tongue Sole CD209: A Pattern-Recognition Receptor that Binds a Broad Range of Microbes and Promotes Phagocytosis
Article Menu
Issue 12 (December) cover image

Export Article

Open AccessArticle
Int. J. Mol. Sci. 2017, 18(12), 2694;

Exploring the Caste-Specific Multi-Layer Defense Mechanism of Formosan Subterranean Termites, Coptotermes formosanus Shiraki

Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510640, China
Laboratory of Bio-control and Molecular Biology, Department of Arid Land Agriculture, College of Agricultural and Food Sciences, King Faisal University, 31982 Hofuf, Al-Ahsa, Saudi Arabia
Author to whom correspondence should be addressed.
Received: 7 November 2017 / Revised: 6 December 2017 / Accepted: 7 December 2017 / Published: 12 December 2017
(This article belongs to the Special Issue Host-Microbe Interaction 2018)
Full-Text   |   PDF [5148 KB, uploaded 13 December 2017]   |  


The survival and foraging of Coptotermes formosanus 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 Metarhizium anisopliae and Beauveria bassiana 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. View Full-Text
Keywords: antioxidant defense; castes; disease resistance; HS-SPME; SEM; termites; volatiles antioxidant defense; castes; disease resistance; HS-SPME; SEM; termites; volatiles

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Hussain, A.; Wen, S.-Y.; Tian, M.-Y. Exploring the Caste-Specific Multi-Layer Defense Mechanism of Formosan Subterranean Termites, Coptotermes formosanus Shiraki. Int. J. Mol. Sci. 2017, 18, 2694.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top