摘要 : Trichomes are specialized epidermal cells that generally play a role in reducing transpiration and act as a deterrent to herbivory. In a screen of activation-tagged <i>Populus tremula</i> x <i>Populus alba</i> 717-1 B4 trees, we i... 展开 Trichomes are specialized epidermal cells that generally play a role in reducing transpiration and act as a deterrent to herbivory. In a screen of activation-tagged <i>Populus tremula</i> x <i>Populus alba</i> 717-1 B4 trees, we identified a mutant line, <i>fuzzy</i>, with increased foliar trichome density. This mutant also had a 35% increase in growth rate and a 200% increase in the rate of photosynthesis as compared with wild-type poplar. The <i>fuzzy</i> mutant had significant resistance to feeding by larvae of the white-spotted tussock moth (<i>Orgyia leucostigma</i>), a generalist insect pest of poplar trees. The <i>fuzzy</i> trichome phenotype is attributable to activation tagging and increased expression of the gene encoding <i>PtaMYB186</i>, which is related to <i>Arabidopsis thaliana MYB106</i>, a known regulator of trichome initiation. The <i>fuzzy</i> phenotype can be recapitulated by overexpressing <i>PtaMYB186</i> in poplar. <i>PtaMYB186</i> overexpression results in reconfiguration of the poplar transcriptome, with changes in the transcript abundance of suites of genes that are related to trichome differentiation. It is notable that a plant with misexpression of a gene responsible for trichome development also had altered traits related to growth rate and pest resistance, suggesting that non-intuitive facets of plant development might be useful targets for plant improvement.Digital Object Identifier http://dx.doi.org/10.1111/j.1365-313X.2010.04343.x 收起