Vendemiatti Eloisa, Zsögön Agustin, Silva Geraldo Felipe Ferreira E, de Jesus Frederico Almeida, Cutri Lucas, Figueiredo Cassia Regina Fernandes, Tanaka Francisco André Ossamu, Nogueira Fábio Tebaldi Silveira, Peres Lázaro Eustáquio Pereira
Departament of Biological Sciences, Escola Superior de Agricultura "Luiz de Queiroz", University of São Paulo (USP), Av. Pádua Dias, 11, CP 09, 13418-900, Piracicaba, SP, Brazil.
Departament of Plant Biology, Universidade Federal de Viçosa (UFV), Av. Peter Henry Rolfs s/n, 36570-900, Viçosa, MG, Brazil.
Plant Sci. 2017 Jun;259:35-47. doi: 10.1016/j.plantsci.2017.03.006. Epub 2017 Mar 14.
Glandular trichomes are structures with widespread distribution and deep ecological significance. In the Solanum genus, type-IV glandular trichomes provide resistance to insect pests. The occurrence of these structures is, however, poorly described and controversial in cultivated tomato (Solanum lycopersicum). Optical and scanning electron microscopy were used to screen a series of well-known commercial tomato cultivars, revealing the presence of type-IV trichomes on embryonic (cotyledons) and juvenile leaves. A tomato line overexpressing the microRNA miR156, known to promote heterochronic development, and mutants affecting KNOX and CLAVATA3 genes possessed type-IV trichomes in adult leaves. A re-analysis of the Woolly (Wo) mutant, previously described as enhancing glandular trichome density, showed that this effect only occurs at the juvenile phase of vegetative development. Our results suggest the existence of at least two levels of regulation of multicellular trichome formation in tomato: one enhancing different types of trichomes, such as that controlled by the WOOLLY gene, and another dependent on developmental stage, which is fundamental for type-IV trichome formation. Their combined manipulation could represent an avenue for biotechnological engineering of trichome development in plants.
腺毛是分布广泛且具有重要生态意义的结构。在茄属植物中，IV型腺毛可抵御害虫。然而，这些结构在栽培番茄（Solanum lycopersicum）中的出现情况描述甚少且存在争议。利用光学显微镜和扫描电子显微镜对一系列知名商业番茄品种进行筛选，发现在胚胎期（子叶）和幼叶上存在IV型腺毛。一个过表达已知可促进异时发育的microRNA miR156的番茄株系以及影响KNOX和CLAVATA3基因的突变体在成年叶片上具有IV型腺毛。对先前描述为可增加腺毛密度的Woolly（Wo）突变体进行重新分析，结果表明这种效应仅发生在营养发育的幼年期。我们的结果表明，番茄多细胞腺毛形成至少存在两个调控水平：一个增强不同类型的腺毛，如由WOOLLY基因控制的腺毛；另一个依赖于发育阶段，这对IV型腺毛的形成至关重要。它们的联合操作可能为植物腺毛发育的生物技术工程提供一条途径。
