Fitness Costs and Benefits of An Induced Defense

小行星9505950 许多原生植物在受到食草动物攻击时，其组织中有毒代谢物的浓度会增加。 虽然对这些反应的机制的理解已经迅速提高，但对其重要性的理解仍然有限。 这些伤口诱导的反应是否起到防御作用，使植物更能抵抗进一步的攻击？ 如果这些反应保护植物，为什么防御部署诱导？ 有两类理论被提出来解释诱导性：1）假设诱导性性状是一种节约成本的措施，通过允许植物根据防御需要来分配资源以降低防御的资源成本，以及2）不做这种假设的理论。 本研究通过使用1）最近鉴定的激活诱导防御的损伤信号，和2）负责产生损伤信号的酶的抑制剂，这将允许抑制受攻击植物中的诱导防御，通过测试诱导防御对田间植物适应性的益处和成本来检查这些问题。 这项工作的结果将对可持续农业做法的发展具有重要意义，因为它将发展摆脱外源添加农药的害虫抗药性方法。 转基因技术极大地促进了在不同物种之间转移有效抗性性状并控制这些性状在作物中的表达的能力。 如果这些新性状要在农业中可持续发展，了解不同类型表达的成本和效益至关重要。

9505950 Baldwin Many native plants increase the concentration of toxic metabolites in their tissues when they are attacked by herbivores. While understanding of the mechanisms responsible for these responses has advanced rapidly, understanding of their significance remains limited. Do these wound-induced responses function as defenses, making plants more resistant to further attack? If these responses protect plants, why are the defenses inducibly deployed? Two classes of theories have been proposed to explain inducibility: 1) theories which assume that the inducible trait is a cost-savings measure which reduces the resource cost of defense by allowing plants to time the allocation of resources to defense with the need for defense, and 2) theories which do not make this assumption. This research examines these questions by testing both the benefits and the costs of an induced alkaloidal defense to plant fitness in the field by using 1) a recently identified damage signal which activates the induced defense, and 2) an inhibitor of enzymes responsible for producing the damage signal, which will allow suppression of the induced defense in attacked plants. The results of this work will be important for the development of sustainable agricultural practices by developing approaches to pest resistance that move away from the exogenous addition of pesticides. Transgenic technology has greatly facilitated the ability to move potent resistance traits among different species and controlling the expression of these traits in crop plants. Understanding the costs and benefits of different types of expression is essential if these new traits are to be sustainable in agriculture.