The Chemical Defenses of Plants to Pathogens and Herbivores
The Chemical Defenses of Plants to Pathogens and Herbivores
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植物对病原体和食草动物的化学防御
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
D. Levin
中科院分区：
文献类型：
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作者：
D. Levin
植物种群在其生命周期的各个阶段都受到病原体和食草动物的攻击。虫害的压力可能是毁灭性的，栽培和本地植物中昆虫和疾病的爆发（121、173、178、198、329）和生物手段控制杂草的成功（6、141、338、340）都说明了这一点。流行病或密集草食的发作可能直接导致植物物种的局部灭绝，或可能削弱植物并使其易受后续压力的影响。由于疾病或部分落叶导致的光合能力丧失降低了对非生物胁迫或其他害虫感染的抵抗力，并降低了竞争能力（198,240,270）。对病原体和食草动物的防御可能有许多不同的机制；它可能取决于植物表面的质地和组成（156,182,196,242），解剖结构如刺或树脂管的存在（123,199,229），害虫所需营养物质的缺乏（140），影响昆虫发育的激素样物质的存在（335），不合适的pH值或渗透压（18,199,229），或二次产物的积累（47,92,169,298）。这些产品种类繁多，从生物碱到萜烯；酚醛树脂;还有类固醇，氰基和芥末油苷。一些物质（如酚类物质）在种子植物中普遍存在，另一些物质（如生物碱）存在于几千种植物中，而另一些物质（如氰苷）仅存在于几百种植物中（61）。次生产物可能被隔离在细胞或细胞器内，只有当细胞破裂时才释放出来。它们也可能储存在无根的表皮腺或毛状体中并由表皮腺分泌（19,69,156,182,187,269）。典型地，腺渗出液只含有一类化合物，但这一类在不同的物种中是不同的。腺体分泌物通常为萜类、生物碱、萜类
Populations of plants are subject to attack by pathogens and herbivores at all stages of their life cycles. Pest pressure may be devastating, as illustrated by the outbreaks of insects apd diseases in cultivated and native plants (121, 173, 178, 198, 329) and in the success of weed control by biotic instruments (6, 141, 338, 340). Epidemics or episodes of intensive herbivory may lead directly to the local extinction of a plant species, or may weaken plants and make them vulnerable to subsequent pressures. Loss of photosynthetic capacity due to disease or partial defoliation lowers resistance to abiotic stresses or to infection by other pests, and reduces competitive ability (198, 240, 270). Defense against pathogens and herbivores may be secured by many different mechanisms; it may depend on the texture and composition of the plant surface (156, 182, 196, 242), the presence of anatomical structures such as thorns or resin ducts (123, 199, 229), the absence of nutrients required by the pest (140), the presence of hormonelike substances that affect the development of insects (335), unsuitable pH or osmotic pressure (18, 199, 229), or the accumulation of secondary products (47, 92, 169, 298). These products are diverse, ranging from alkaloids to terpenes; phenolics; and steroidal, cyanogenic, and mustard oil glycosides. Some (e.g. phenolics) are ubiquitous in seed plants, others (e.g. alkaloids) occur in several thousand species and others (e.g. cyanogenic glycosides) occur in only a few hundred species (61). Secondary products may be sequestered within cells or organelles therein and released only when the cells are broken. They also may be stored in and secreted by epidermal glands which are sessile or on trichomes (19, 69, 156, 182, 187, 269). Typically, glandular exudates contain only one class of compound, but this class varies among species. The glandular exudates usually are terpens, alkaloids, res-