1
|
Thakur H, Agarwal S, Buček A, Hradecký J, Sehadová H, Mathur V, Togaev U, van de Kamp T, Hamann E, Liu RH, Verma KS, Li HF, Sillam-Dussès D, Engel MS, Šobotník J. Defensive glands in Stylotermitidae (Blattodea, Isoptera). ARTHROPOD STRUCTURE & DEVELOPMENT 2024; 79:101346. [PMID: 38520874 DOI: 10.1016/j.asd.2024.101346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 03/25/2024]
Abstract
The large abundance of termites is partially achieved by their defensive abilities. Stylotermitidae represented by a single extant genus, Stylotermes, is a member of a termite group Neoisoptera that encompasses 83% of termite species and 94% of termite genera and is characterized by the presence of the frontal gland. Within Neoisoptera, Stylotermitidae represents a species-poor sister lineage of all other groups. We studied the structure of the frontal, labral and labial glands in soldiers and workers of Stylotermes faveolus, and the composition of the frontal gland secretion in S. faveolus and Stylotermes halumicus. We show that the frontal gland is a small active secretory organ in soldiers and workers. It produces a cocktail of monoterpenes in soldiers, and some of these monoterpenes and unidentified proteins in workers. The labral and labial glands are developed similarly to other termite species and contribute to defensive activities (labral in both castes, labial in soldiers) or to the production of digestive enzymes (labial in workers). Our results support the importance of the frontal gland in the evolution of Neoisoptera. Toxic, irritating and detectable monoterpenes play defensive and pheromonal functions and are likely critical novelties contributing to the ecological success of these termites.
Collapse
Affiliation(s)
- Himanshu Thakur
- Department of Entomology, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, Himachal Pradesh, India
| | - Surbhi Agarwal
- Animal Plant Interactions Lab, Department of Zoology, Sri Venkateswara College, Benito Juarez Marg, Dhaula Kuan, New Delhi, India
| | - Aleš Buček
- Biology Centre, Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
| | - Jaromír Hradecký
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Hana Sehadová
- Biology Centre, Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic; University of South Bohemia in Ceske Budejovice, Branišovská 31, 370 05, Ceske Budejovice, Czech Republic
| | - Vartika Mathur
- Animal Plant Interactions Lab, Department of Zoology, Sri Venkateswara College, Benito Juarez Marg, Dhaula Kuan, New Delhi, India
| | - Ulugbek Togaev
- Academy of Science of Uzbekistan, Institute of Bioorganic Chemistry and National University of Uzbekistan, Tashkent, Uzbekistan
| | - Thomas van de Kamp
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany; Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76131, Karlsruhe, Germany
| | - Elias Hamann
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Ren-Han Liu
- Department of Entomology, National Chung Hsing University, Taichung, 402202, Taiwan
| | - Kuldeep S Verma
- Department of Entomology, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, Himachal Pradesh, India
| | - Hou-Feng Li
- Department of Entomology, National Chung Hsing University, Taichung, 402202, Taiwan
| | - David Sillam-Dussès
- University Sorbonne Paris Nord, Laboratory of Experimental and Comparative Ethology, LEEC, UR 4443, Villetaneuse, France.
| | - Michael S Engel
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, 10024-5192, USA
| | - Jan Šobotník
- Biology Centre, Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic; Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czech Republic.
| |
Collapse
|
2
|
Comparative Genomic and Metabolomic Analysis of Termitomyces Species Provides Insights into the Terpenome of the Fungal Cultivar and the Characteristic Odor of the Fungus Garden of Macrotermes natalensis Termites. mSystems 2022; 7:e0121421. [PMID: 35014870 PMCID: PMC8751386 DOI: 10.1128/msystems.01214-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Macrotermitinae termites have domesticated fungi of the genus Termitomyces as food for their colony, analogously to human farmers growing crops. Termites propagate the fungus by continuously blending foraged and predigested plant material with fungal mycelium and spores (fungus comb) within designated subterranean chambers. To test the hypothesis that the obligate fungal symbiont emits specific volatiles (odor) to orchestrate its life cycle and symbiotic relations, we determined the typical volatile emission of fungus comb biomass and Termitomyces nodules, revealing α-pinene, camphene, and d-limonene as the most abundant terpenes. Genome mining of Termitomyces followed by gene expression studies and phylogenetic analysis of putative enzymes related to secondary metabolite production encoded by the genomes uncovered a conserved and specific biosynthetic repertoire across strains. Finally, we proved by heterologous expression and in vitro enzymatic assays that a highly expressed gene sequence encodes a rare bifunctional mono-/sesquiterpene cyclase able to produce the abundant comb volatiles camphene and d-limonene. IMPORTANCE The symbiosis between macrotermitinae termites and Termitomyces is obligate for both partners and is one of the most important contributors to biomass conversion in the Old World tropic’s ecosystems. To date, research efforts have dominantly focused on acquiring a better understanding of the degradative capabilities of Termitomyces to sustain the obligate nutritional symbiosis, but our knowledge of the small-molecule repertoire of the fungal cultivar mediating interspecies and interkingdom interactions has remained fragmented. Our omics-driven chemical, genomic, and phylogenetic study provides new insights into the volatilome and biosynthetic capabilities of the evolutionarily conserved fungal genus Termitomyces, which allows matching metabolites to genes and enzymes and, thus, opens a new source of unique and rare enzymatic transformations.
Collapse
|
3
|
Effect of Spatial Variation on Defensive Substances of Constrictotermes Cyphergaster Soldiers (Blattaria, Isoptera). J Chem Ecol 2021; 47:544-551. [PMID: 33796949 DOI: 10.1007/s10886-021-01271-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 03/10/2021] [Accepted: 03/23/2021] [Indexed: 10/21/2022]
Abstract
The composition of chemical weaponry of termite soldiers show interspecific and intraspecific variation. However, spatial effects on the qualitative and quantitative compositions of these substances in Neotropical termites are poorly known. Hexane extracts of heads and the defensive secretion of soldiers of Constrictotermes cyphergaster from four localities in Northeast Brazil were analyzed by gas chromatography and mass spectrometry. Chemical analysis allowed the detection of 54 compounds from the head extract and from the direct extraction of the defensive secretion of soldiers, and the percentage of common substances and the presence of exclusive substances varied depending on the spatial distance between colonies. The profile of the chemical armament of soldiers consists basically of terpenoids: monoterpenes (45.53%-71.97 - for head extract and 57.41% - 78.56 for secretion) and sesquiterpenes (19.69% - 35.78% for head extract and 18.41% - 33.31%for secretion). In general, the main component of the chemical arsenal, regardless of the methodology used for extraction, was α-pinene (27.98-50.44%). Two chemotypes were identified based on chemical differences between populations of ecoregions with distinct spatial-environmental and climate characteristics: (1) α-pinene <33%; (2) α-pinene >33% for both extracts (head and secretion). The results reveal a similar pattern of chemical differentiation for soldiers in both extracts (head and secretion), with increasing differences as a function of distance between the analyzed colonies.
Collapse
|
5
|
Sobotník J, Jirosová A, Hanus R. Chemical warfare in termites. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:1012-21. [PMID: 20223240 DOI: 10.1016/j.jinsphys.2010.02.012] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/18/2010] [Accepted: 02/22/2010] [Indexed: 05/10/2023]
Abstract
The rapid development of analytical methods in the last four decades has led to the discovery of a fascinating diversity of defensive chemicals used by termites. The last exhaustive review on termite defensive chemicals was published by G.D. Prestwich in 1984. In this text, we aim to fill the gap of the past 25 years and overview all of the relevant primary sources about the chemistry of termite defense (126 original papers, see Fig. 1 and online supplementary material) along with related biological aspects, such as the anatomy of defensive glands and their functional mechanisms, alarm communication, and the evolutionary significance of these defensive elements.
Collapse
Affiliation(s)
- Jan Sobotník
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám., Prague, Czech Republic
| | | | | |
Collapse
|