CONSTRAINTS ON AN INDUCED DEFENSE - THE ROLE OF LEAF-AREA
CONSTRAINTS ON AN INDUCED DEFENSE - THE ROLE OF LEAF-AREA
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DOI：
10.1007/bf00317335
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发表时间：
1994-04-01
期刊：
影响因子：
2.7
通讯作者：
SCHMELZ, EA
中科院分区：
文献类型：
--
作者：
BALDWIN, IT;SCHMELZ, EA
落叶病导致叶片损伤和光合能力的丧失。叶损伤激活诱导防御的产生，但是由叶面积损失导致的光合能力降低可能损害植物的防御反应能力。由于损伤诱导的烟碱产生在烟草sylvestris（茄科）是一个能量需求，积极的过程，我们预测，叶面积的损失将限制这种植物的能力，产生诱导的烟碱池。我们在一项实验中研究了我们的预测，该实验结合了叶片穿刺和去除方案，在整株植物的基础上量化了诱导的尼古丁库，并考虑了由于去除叶片和失去生长潜力而导致的尼古丁库的损失。与我们的预测相反，叶片去除没有减少足够的损害“线索”的植物诱导尼古丁池的生长校正估计，只有当植物失去了88%或更多的叶面积诱导尼古丁池显着下降。这些结果表明，诱导的防御是相对不敏感的当前光合能力。与诱导尼古丁池的大小相反，在所有脱叶水平测试中，随着穿刺损伤的增加，剩余芽组织中的尼古丁浓度继续上升。负责诱导型尼古丁产生的机制可能已经演变为一种为芽组织提供保护的手段，该保护与所遭受的损害量成比例，同时保持其余植物部分的生产成本恒定。
Folivory results in both leaf damage and the loss of photosynthetic capacity. Leaf damage activates the production of induced defenses, but diminished photosynthetic capacity resulting from lost leaf area may impair a plant's ability to respond defensively. Because damage-induced nicotine production in Nicotiana sylvestris (Solanaceae) is an energy-demanding, active process, we predicted that the loss of leaf area would constrain this plant's ability to produce an induced nicotine pool. We examined our prediction in an experiment which combined leaf puncture and removal protocols, quantified induced nicotine pools on a whole-plant basis, and accounted for losses in the nicotine pool due to removed leaves and lost growth potential. In contrast to our prediction, leaf removal did little to diminish the growth-corrected estimates of the induced nicotine pool in plants with sufficient damage ''cue''; only when plants had lost 88% or more of their leaf area did the induced nicotine pool decline significantly. These results demonstrate that the induced defense is relatively insensitive to current photosynthetic capacity. In contrast to the size of the induced nicotine pool, the concentration of nicotine in the remaining shoot tissues continued to rise as puncture damage increased over all defoliation levels tested. The mechanisms responsible for inducible nicotine production may have evolved as a means of providing shoot tissues with protection that is proportional to the amount of damage incurred while keeping production costs constant for the remaining plant parts.