Herbivore-induced responses in alfalfa (Medicago sativa)
Herbivore-induced responses in alfalfa (Medicago sativa)
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DOI：
10.1023/a:1022625810395
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发表时间：
2003-02-01
影响因子：
2.3
通讯作者：
Anderson, P
中科院分区：
文献类型：
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作者：
Agrell, J;Oleszek, W;Anderson, P
通过对滨海夜蛾（Spodoptera littoralis）幼虫的检测和重要次生物质的分析，探讨了紫花苜蓿（Medicago sativa）对草食诱导的反应。在食物偏好实验中，相对于5天和7天前饲喂的苜蓿幼苗，幼虫更喜欢未受损的幼苗，而在受损后1、9和14天，幼虫的摄食偏好没有差异。这表明草食动物诱导的苜蓿抗性在初始损害后一周左右达到峰值。幼株的诱导抗性也显示为系统性的，而老花植株在落叶后没有表现出增强的抗性。饲喂受损苜蓿的幼虫增重速度慢，蛹质量也低于饲喂未受损苜蓿的幼虫。受损紫花苜蓿叶片中总皂苷含量增加，对特定皂苷成分的详细分析显示，3GlcA、28AraRhaXyl medicagenate（药用酸bidesmoside）和3GlcAGalRha大豆皂苷B（大豆皂苷I）的浓度增加了一倍。草食损伤植物的类黄酮芹菜素（作为游离苷元）水平也增加。草食诱导对苜蓿的反应明显弱于对棉花的反应：当滨海夜蛾幼虫选择未受损的棉花时，未受损的紫花苜蓿更倾向于以棉花为食，而当植物受损时，紫花苜蓿更倾向于以苜蓿为食。
The herbivore-induced response of alfalfa (Medicago sativa) was examined through assays with Spodoptera littoralis larvae and analyses of important secondary substances. In food preference experiments, larvae preferred young undamaged alfalfa plants over plants that had been damaged by feeding larvae 5 and 7 days earlier, while no difference in feeding preferences could be detected 1, 9, and 14 days after damage. This suggests a peak in the herbivore induced resistance of alfalfa approximately one week after initial damage. The induced resistance in young plants was also shown to be systemic, while older flowering plants failed to show increased resistance after defoliation. Larvae gained weight slower and had lower pupal mass when fed damaged alfalfa than when fed undamaged alfalfa. Levels of total saponins were increased in foliage of damaged alfalfa, and detailed analyses of specific saponin components revealed doubled concentrations of 3GlcA, 28AraRhaXyl medicagenate (medicagenic acid bidesmoside) and 3GlcAGalRha soyasapogenol B(soyasaponin I). Levels of the flavonoid apigenin (as free aglycone) also were increased in herbivore damaged plants. The herbivore-induced response of alfalfa was significantly weaker than that of cotton: S. littoralis larvae given a choice of undamaged cotton and undamaged alfalfa preferred to feed on cotton, whereas preferences shifted towards alfalfa when plants were damaged.