Mechanisms of acclimation for desiccation resistance in subterranean termites

Louisiana State University Agricultural Center, Baton Rouge LA

Investigators

Abstract

Maintaining water balance is an increasing challenge for organisms living in drier and warmer environments under climate change. Insects, the most diverse organisms on Earth, are particularly vulnerable to water loss due to their small body size and high metabolic rates. To mitigate the risks of desiccation, insects are equipped with various physiological strategies, such as producing a waterproof barrier on their body surface, altering breathing patterns, and reducing water excretion. However, there is limited understanding of the extent of flexibility in their physiology over their lifetime to cope with changing environments, and even less is known about species living underground that play vital ecological roles. Subterranean termites are widespread wood decomposers, yet some species are serious structural pests, making them an ecologically and economically important group. This study explores how subterranean termites adjust their physiological responses to alterations in soil moisture and temperature, as well as the molecular mechanisms underlying this flexibility, by examining six termite species inhabiting different climate regions across the United States. This understanding carries significant implications for predicting the resilience and susceptibility of termites to climate change and human impacts, thereby informing conservation and management strategies. The research findings will be disseminated through a workshop for the pest control industry and through the development of educational materials for the public. Termites cause billions of dollars of damage in the US each year, thus the work has strong implications for advancing knowledge related to the bio-economy. Furthermore, this project will support underrepresented undergraduate students in conducting summer research projects, while also offering interdisciplinary training opportunities for junior scientists. Determining the acclimation capacity and the mechanisms for organisms to adjust to environmental shifts is critical for understanding the ecological consequences of climate change. While diverse habitats are projected to be affected by droughts and temperature increases, little is known about either the desiccation physiology or the acclimation responses of organisms in subterranean ecosystems. The overall goal of this project is to characterize the acclimation capacity for desiccation resistance and the underlying physiological and molecular mechanisms in subterranean termites. Driven by the hypothesis that greater plasticity in desiccation physiology allows species to better acclimate to drier environments, this research will examine the acclimation responses of six subterranean termite species that represent different phylogenetic statuses and climate adaptation types. Upon acclimation to different soil moisture and temperature conditions, termites will be analyzed for their phenotypic responses to desiccation stress and for physiological changes in desiccation resistance traits, including cuticular hydrocarbon profile, spiracle respiration pattern, and body water reservoir. This study will further investigate their transcriptomic plasticity and the molecular mechanisms underlying the acclimation responses. The results will uncover the conserved and divergent mechanisms governing plasticity in termite desiccation physiology, and will facilitate future proximate and evolutionary investigations of species across taxa and ecological niches. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.