Nonstomatal water loss by transpiration through the hydrophobic cuticle is ubiquitous in land plants, but the pathways along which this occurs have not been identified. Tomato (Solanum lycopersicum) provides an excellent system in which to study this phenomenon, as its fruit are astomatous and a major target for desiccation resistance to enhance shelf life. We screened a tomato core collection of 398 accessions from around the world and selected seven cultivars that collectively exhibited the lowest and highest degrees of transpirational water loss for a more detailed study. The transpirational differences between these lines reflected the permeances of their isolated cuticles, but this did not correlate with various measures of cuticle abundance or composition. Rather, we found that fruit cuticle permeance has a strong dependence on the abundance of microscopic polar pores. We further observed that these transcuticular pores are associated with trichomes and are exposed when the trichomes are dislodged, revealing a previously unreported link between fruit trichome density and transpirational water loss. During postharvest storage, limited self-sealing of the pores was detected for certain cultivars, in contrast with the stem scar, which healed relatively rapidly. The abundance of trichome-associated pores, together with their self-sealing capacity, presents a promising target for breeding or engineering efforts to reduce fruit transpirational water loss.

在陆地植物中普遍存在通过疏水性表皮蒸腾作用而引起的非气孔失水现象，但尚未确定发生这种现象的途径。番茄（Solanum lycopersicum）提供了一个很好的系统来研究这种现象，因为番茄的果实是无毒的，并且是抗干燥性的主要目标，以延长保质期。我们筛选了来自世界各地的398个种质的番茄核心种质，选择了七个表现出最低和最高蒸腾失水程度的品种，以进行更详细的研究。这些线之间的蒸腾作用差异反映了它们分离的角质层的渗透性，但这与角质层丰度或组成的各种测量值无关。而是 我们发现，水果角质层的渗透性对微观极孔的丰度有很强的依赖性。我们进一步观察到这些经皮毛孔与毛状体相关，并在毛状体被移出时暴露，从而揭示了水果毛状体密度与蒸腾失水之间先前未报道的联系。在收获后的存储过程中，某些品种的毛孔自密封性有限，而茎疤痕则相对较快愈合。毛状体相关毛孔的丰富性及其自密封能力为减少水果蒸腾失水的育种或工程工作提出了一个有希望的目标。当毛状体被移出时暴露出来，揭示了水果毛状体密度与蒸腾失水之间先前未报道的联系。在收获后的存储过程中，某些品种的毛孔自密封性有限，而茎疤痕则相对较快愈合。毛状体相关毛孔的丰富性及其自密封能力为减少水果蒸腾失水的育种或工程工作提出了一个有希望的目标。当毛状体被移出时暴露出来，揭示了水果毛状体密度与蒸腾失水之间先前未报道的联系。在收获后的存储过程中，某些品种的毛孔自密封性有限，而茎疤痕则相对较快愈合。毛状体相关毛孔的丰富性及其自密封能力为减少水果蒸腾失水的育种或工程工作提出了一个有希望的目标。