<i>Serratia symbiotica</i> Enhances Fatty Acid Metabolism of Pea Aphid to Promote Host Development
Bacterial symbionts associated with insects are often involved in host development and ecological adaptation. <i>Serratia symbiotica</i>, a common facultative endosymbiont harbored in pea aphids, improves host fitness and heat tolerance, but studies concerning the nutritional metabolism...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-05-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/11/5951 |
| Summary: | Bacterial symbionts associated with insects are often involved in host development and ecological adaptation. <i>Serratia symbiotica</i>, a common facultative endosymbiont harbored in pea aphids, improves host fitness and heat tolerance, but studies concerning the nutritional metabolism and impact on the aphid host associated with carrying <i>Serratia</i> are limited. In the current study, we showed that <i>Serratia</i>-infected aphids had a shorter nymphal developmental time and higher body weight than <i>Serratia</i>-free aphids when fed on detached leaves. Genes connecting to fatty acid biosynthesis and elongation were up-regulated in <i>Serratia</i>-infected aphids. Specifically, elevated expression of fatty acid synthase 1 (<i>FASN1</i>) and diacylglycerol-o-acyltransferase 2 (<i>DGAT2</i>) could result in accumulation of myristic acid, palmitic acid, linoleic acid, and arachidic acid in fat bodies. Impairing fatty acid synthesis in <i>Serratia</i>-infected pea aphids either by a pharmacological inhibitor or through silencing <i>FASN1</i> and <i>DGAT2</i> expression prolonged the nymphal growth period and decreased the aphid body weight. Conversely, supplementation of myristic acid (C14:0) to these aphids restored their normal development and weight gain. Our results indicated that <i>Serratia</i> promoted development and growth of its aphid host through enhancing fatty acid biosynthesis. Our discovery has shed more light on nutritional effects underlying the symbiosis between aphids and facultative endosymbionts. |
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| ISSN: | 1661-6596 1422-0067 |