College of Horticulture/Yuelu Mountain Laboratory of Hunan Province, Hunan Agricultural University, Changsha, China.
Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan.
Nat Plants. 2024 Mar;10(3):381-389. doi: 10.1038/s41477-024-01626-x. Epub 2024 Feb 19.
Successful biochemical reactions in organisms necessitate compartmentalization of the requisite components. Glandular trichomes (GTs) act as compartments for the synthesis and storage of specialized compounds. These compounds not only are crucial for the survival of plants under biotic and abiotic stresses but also have medical and commercial value for humans. However, the mechanisms underlying compartmentalization remain unclear. Here we identified a novel structure that is indispensable for the establishment of compartments in cucumber GTs. Silica, a specialized compound, is deposited on the GTs and is visible on the surface of the fruit as a white powder, known as bloom. This deposition provides resistance against pathogens and prevents water loss from the fruits. Using the cucumber bloomless mutant, we discovered that a lignin-based cell wall structure in GTs, named 'neck strip', achieves compartmentalization by acting as an extracellular barrier crucial for the silica polymerization. This structure is present in the GTs of diverse plant species. Our findings will enhance the understanding of the biosynthesis of unique compounds in trichomes and provide a basis for improving the production of compounds beneficial to humans.
生物体内成功的生化反应需要必需成分的分隔化。腺体毛状体（GTs）充当合成和储存特殊化合物的隔室。这些化合物不仅对植物在生物和非生物胁迫下的生存至关重要，而且对人类也具有医学和商业价值。然而，分隔化的机制仍不清楚。在这里，我们鉴定了一个在黄瓜 GTs 中建立隔室所必需的新型结构。硅是一种特殊的化合物，沉积在 GTs 上，并在果实表面作为白色粉末（称为花粉）可见。这种沉积提供了对病原体的抵抗力，并防止果实失水。使用黄瓜无花粉突变体，我们发现 GTs 中的木质素基细胞壁结构“颈带”通过充当对硅聚合至关重要的细胞外屏障来实现分隔化。该结构存在于多种植物物种的 GTs 中。我们的发现将增强对毛状体中独特化合物生物合成的理解，并为提高对人类有益化合物的产量提供基础。
