Acta Ecologica Sinica (2007) 27, 1565-1572

Yao Du, Chun-Sen Ma, Qing-Hua Zhao, Gang Ma and He-Ping Yang (2007)
Effects of heat stress on physiological and biochemical mechanisms of insects: a literature review
Acta Ecologica Sinica 27 (4), 1565-1572
Abstract: Temperature determines life of insectsmore than many other environmental factors. The most popularmethod to p redict the population development of insects is based on the initial population density of insects at certain time and the environment temperatures during a certain time period. However, the accuracy of the prediction may reduce because of the unknown effects of very comp licated high2temperature patterns under field conditions on development, rep roduction and survival of the insects. We summarized and reviewed the research results of physiological and biochemical effects of high temperature on insects. Extreme high temperature lead to the wax of the cuticle breaking down, lipid melting, and permeability to water consequently increasing dramatically. The concentrations of important ions in insect cells are changed at high temperature, then consequently altering the charge state of the macromolecular components of the cell and influencing the function of the macromolecules. High temperature makes cytoskeleton collapse and causes cells destroyed, the fatty acid composition of its phosphoglycerides changed and the "fluidity" of cellular membranes reduced. High temperature results in an increase in the kinetic energy of the macromolecule, thereby decreasing the ionic, hydrogen, and van der Waals bonds and increasing hydrophobic interactions of the macromolecule. This, in turn, reduces the ability of the macromolecule to hold its shape and spatial conformation. The structures and functions of DNA and RNA are changed at high temperature, thus the stable heredity of characters is badly affected. The kinds of proteins and quantities of each one in cell are changed. At high temperature, the normal pattern of protein synthesis is suppressed, whereas the system for heat shock conditions is opened. The spatial conformation and function of normal proteins are altered, and new proteins (such as heat shock protein) are produced at the same time. High temperature inhabits the activity of acetylcholinesterase and disturbs the nerve conduction, and consequently makes insects lose the ability of escaping from detrimental conditions. In addition, the metabolism of lipids and oligosaccharide (e.g. fucose) is affected by high temperature. We discussed the potential logic relations of various changes in physiology and biochemistry of insects at high temperature, and suggested a hypothesis about the heat injury process to insects. The injury mechanisms of high2temperatures on insects may differ at varying temperature degrees. At last, we pointed out the important aspects in this area needed to be investigated in future. It includes (1) the most sensitive part of the insect′s body to high temperature; (2) key steps to form a complete mechanism of heat injury to insects; (3) mechanism for induction of heat tolerance; and (4) reasons in biochemistry for different responses of different development stages of insects to heat stress.
(The abstract has been supplied by the author or ISPI and is excluded from the Creative Commons licence.)
(original language: Chinese)
Database assignments for author(s): Chun-Sen Ma

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
review

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.