Specificity of constitutive and induced resistance: pigment glands influence mites and caterpillars on cotton plants
Specificity of constitutive and induced resistance: pigment glands influence mites and caterpillars on cotton plants
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DOI：
10.1023/a:1004073411100
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发表时间：
2000-07-01
影响因子：
1.9
通讯作者：
Karban, R
中科院分区：
文献类型：
--
作者：
Agrawal, AA;Karban, R
棉花植物含有一系列被认为在防御食草动物中重要的植物化学物质，其中一些位于含有棉酚和其他萜类醛的色素腺中。这些腺体表达的简单遗传基础导致了近等基因的有腺体和无腺体基因型的发展。腺体也可以由食草动物表型诱导。我们确定了两种类型的食草动物，叶螨（细胞内容物饲养者）和毛虫（叶咀嚼者）的组成性和诱导腺体表达的后果。腺体的诱导强烈依赖于攻击者的密度。与对照相比，叶螨取食处理（1）使子叶腺体密度（而非总数）呈线性增加，（2）使第一真叶腺体密度和总数呈线性增加，（3）对第二真叶腺体密度和总数呈非线性影响。无论是组成性的，也不诱导表达的腺体影响螨种群的增长。诱导腺体和腺体无植物（50%）相对于未诱导的对照组的螨种群大小的相等减少表明，腺体以外的因素与诱导抗螨。组成腺的表达对毛虫的表现有很强的负面影响，使生长减少了45%。诱导抗性毛虫是3倍强，在腺体的基因型比无腺体的基因型，表明与诱导抗性毛虫的因素与腺体密切相关。3个棉花品种对螨类和毛虫的组成型和诱导型抗性差异很大，因此，棉花对植食性害虫的防御可大致分为与萜醛类色素腺体相关的组成型和诱导型因子，前者对毛虫有效，后者对螨类有效。
Cotton plants contain suites of phytochemicals thought to be important in defense against herbivores, some of which are localized in pigment glands which contain gossypol and other terpenoid aldehydes. The simple genetic basis for the expression of these glands has led to the development of near-isogenic glanded and glandless genotypes. Glands may also be phenotypically induced by herbivory. We determined the consequences of constitutive and induced gland expression on two types of herbivores, spider mites (cell content feeders) and noctuid caterpillars (leaf chewers).Induction of glands was strongly dependent on the density of attackers. Spider mite herbivory on cotyledons (1) increased the density (but not total number) of glands on cotyledons linearly, (2) increased the density and total number of glands on the first true leaf linearly, and (3) affected the density and total number of glands on the second true leaf non-linearly, compared to controls. Neither constitutive nor induced expression of glands affected mite population growth. An equal reduction of mite population size on induced glanded and glandless plants (50%) relative to uninduced controls indicated that factors other than glands were associated with induced resistance to mites. Constitutive gland expression had a strong negative impact on caterpillar performance, reducing growth by 45%. Induced resistance to caterpillars was three times stronger in glanded genotypes than in glandless genotypes, indicating that factors associated with induced resistance to caterpillars are strongly associated with glands. Three cotton varieties were highly variable in their constitutive and induced resistance to mites and caterpillars.Thus, defense of cotton plants against herbivores can be roughly categorized as constitutive and inducible factors associated with terpenoid aldehyde containing pigment glands that are effective against caterpillars, and factors not associated with glands that are effective against mites.