Submitted to: Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2010
Publication Date: 2/21/2011
Citation: Garczynski, S.F., Unruh, T.R., Guedot, C.N., Neven, L.G. 2011. Characterization of three transcripts encoding small heat shock proteins expressed in the codling moth, Cydia pomonella (Lepidoptera: Tortricidae). Insect Science. 18:473-483. DOI:10.1111/j.1744-7917.2011.01401.x.
Interpretive Summary: To reduce chemical insecticide contamination of the environment, apple and pear growers need non-pesticidal methods to control codling moth, the major insect pest that causes fruit damage. Scientists at the USDA-ARS Yakima Agricultural Research Laboratory in Wapato, WA are conducting research to identify physiological targets in the codling moth that will lead to the enhancement of current methods used to control this tree fruit pest. This report contains up to date information regarding proteins that protect insects during exposure to environmental stressors, including heat. Heat treatments are applied to control codling moth post-harvest. Understanding the codling moth’s heat shock response will potentially lead to more effective post-harvest heat treatments.
Technical Abstract: Codling moth is a major pest of apples and pears worldwide. Increasing knowledge of how this insect responds to environmental stress will improve field and postharvest control measures used against it. The small heat shock proteins (sHsps) play a major role in cellular responses to environmental stressors. A degenerate oligonucleotide primer, designed against the conserved a-crystallin domain, was used in 3’ RACE reactions to amplify transcripts encoding sHsps expressed in the codling moth cell line, Cp169, subjected to heat shock. Three full-length cDNAs were cloned from Cp169 cells that contained open reading frames encoding sHsps. The cDNA for CpHsp19.8 was 795 bp encoding 177 amino acids. The cDNA for CpHsp19.9 was 749 bp encoding 175 amino acids. The cDNA for CpHsp22.2 was 737 bp encoding 192 amino acids. Analysis of the protein sequences of the three CpHsps indicated the presence of 83 amino acids with homology to the a-crystallin domain. For each of the CpHsps, the a-crystallin domain was surrounded by divergent N- and C-terminal regions, consistent with the conserved structural features of sHsps. Real-time PCR, used to determine the expression patterns of each of the sHsps in different developmental stages of codling moth revealed the presence of transcripts in all stages tested. Consistent with characteristics of other sHsps, expression of CpHsp transcripts were greatly enhanced when insects were subjected to heat shock. The results of this research can be used as a guide to study the roles of sHsps in codling moth control using various postharvest treatments.