Document Type

Article

Publication Date

6-2010

Journal or Book Title

Environmental Entomology

Volume

39

Issue

3

First Page

856

Last Page

864

DOI

10.1603/EN09338

Abstract

Although soybean aphid (Aphis glycines) resistance is commercially available in the form of the Rag1 gene, the mechanism of this resistance is not fully understood. Amino acids are a limiting factor for aphid growth, and there is evidence that plant amino acid composition is related to aphid resistance. Antibiotic resistance like that conferred by Rag1 could be associated in part with both protein and nonprotein free amino acids reducing survival, growth, and fecundity of the target pest. We posed two hypotheses: (1) A.glycines resistance is related to host quality in terms of free amino acids composition in the leaf, and (2) aphids may enhance host quality by inducing changes in the free amino acids composition. To test these hypotheses we conducted a field experiment using a split plot design, with soybean lines (a susceptible line and a related line carrying Rag1) as whole plots and aphid density as subplots (insecticide treated or left exposed to natural infestations). We analyzed free amino acids in leaves at three soybean developmental stages in all subplots. We observed significant whole and subplot effects on the concentration of a subset of amino acids tested. Susceptible and resistant plants had constitutive (whole-plot) differences in amino acids composition in all developmental stages analyzed. In addition, aphid-induced (subplot) responses of the plant to aphid infestation were found. We propose that the reduced nutritional quality of the resistant line and its reduced susceptibility to aphid-induced changes may contribute to aphid resistance conferred by Rag1.

Comments

This article is from Environmental Entomology 39(3):856-864. 2010
doi: 10.1603/EN09338

Rights

This article is the copyright property of the Entomological Society of America and may not be used for any commercial or other private purpose without specific written permission of the Entomological Society of America.

Copyright Owner

Entomological Society of America

Language

en

File Format

pdf

File Size

172,032 bytes

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