The plant cuticle is the final barrier for volatile organic compounds (VOCs) to cross for release to the atmosphere, yet its role in the emission process is poorly understood. Here, using a combination of reverse-genetic and chemical approaches, we demonstrate that the cuticle imposes substantial resistance to VOC mass transfer, acting as a sink/concentrator for VOCs and hence protecting cells from the potentially toxic internal accumulation of these hydrophobic compounds. Reduction in cuticle thickness has differential effects on individual VOCs depending on their volatility, and leads to their internal cellular redistribution, a shift in mass transfer resistance sources and altered VOC synthesis. These results reveal that the cuticle is not simply a passive diffusion barrier for VOCs to cross, but plays the aforementioned complex roles in the emission process as an integral member of the overall VOC network.

植物角质层是挥发性有机化合物 (VOC) 穿过以释放到大气中的最后一道屏障，但其在排放过程中的作用却知之甚少。在这里，我们使用反向遗传和化学方法的组合，证明角质层对 VOC 质量转移具有显着的抵抗力，充当 VOC 的汇/浓缩器，从而保护细胞免受这些疏水化合物的潜在毒性内部积累。表皮厚度的减少对单个 VOC 具有不同的影响，具体取决于它们的挥发性，并导致它们的内部细胞重新分布、传质阻力源的转变和 VOC 合成的改变。这些结果表明，角质层不仅仅是 VOC 穿过的被动扩散屏障，