期刊
ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY
卷 51, 期 4, 页码 204-221出版社
WILEY
DOI: 10.1002/arch.10062
关键词
Bradysia impatiens; Spinacia oleracea; 20-hydroxyecdysone; phytoecdysteroid; defense
Plant produced insect molting hormones, termed phytoecdysteroids (PEs), are thought to function as plant defenses against insects by acting as either feeding deterrents or through developmental disruption. In spinach (Spinacia oleracea), 20-hydroxyecdysone (20E) concentrations in the roots rapidly increase following root damage, root herbivory, or methyl jasmonate (MJ) applications. In this inducible system, we investigated the plant defense hypothesis by examining interactions of roots, 20E concentrations, and larvae of the dark-winged fungus gnat (Bradysia impatiens). Root herbivory by B. impatiens larvae resulted in a 4.0- to 6.6-fold increase in foot 20E concentrations. In paired-choice tests, increases in dietary 20E stimulated B. impatiens feeding deterrency, B. impatiens larvae preferred control diets, low in 20E, to those constructed from induced roots and those amended with 20E (25 to 50 mug/g wet mass). When confined to 20E-treated diets, concentrations as low as 5 mug/g (wet mass) resulted in significantly reduced B. impatiens survivorship compared to controls. The induction of root 20E levels with MJ resulted in a 2.1-fold increase in 20E levels and a 50% reduction in B. impatiens larval establishment. In a paired-choice arena, untreated control roots were damaged significantly more by B. impatiens larvae than MJ-induced roots that contained 3-fold greater 20E levels. Based on dietary preference tests, the 20E concentrations present in the MJ-induced roots (28 mug/g wet mass) were sufficient to explain this reduction in herbivory. Interactions between spinach roots and B. impatiens larvae demonstrate that PEs can act as inducible defenses and provide protection against insect herbivory. Published 2002 Wiley-Liss, Inc.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据