School of Biological Sciences, Illinois State University, Normal, IL, 61790, USA.
Planta. 2019 Apr;249(4):1063-1071. doi: 10.1007/s00425-018-3063-y. Epub 2018 Dec 7.
Arabidopsis Mediator subunits 2, 14, 15a, 16, and 25 are required for papillae development on the trichome cell wall surface. Arabidopsis leaf hairs exhibit raised protrusions, termed papillae, on their cell wall surfaces. Here, we show that the glassy hair mutant, glh2, exhibits trichomes with an approximate 11-fold decrease in papillae density on their surfaces in comparison to wild type. This phenotype was found to be the result of mutations in Arabidopsis Mediator subunit 16. MED16 is localized to the nucleus of trichomes, consistent with Mediator's role in transcription. The expression patterns of the trichome development reporters, ETR2pro::GUS and GL2pro::GUS, as well as GL2 transcript levels were not altered in the glh2 mutant. Screening of available T-DNA insertion lines in other subunits of the Mediator tail module revealed glassy trichome phenotypes in med2, med14, and med15a mutants. The data suggest that the Mediator complex is required for expression of genes involved in trichome papillae development.
拟南芥中介体亚基 2、14、15a、16 和 25 对于表皮毛细胞壁表面的乳突发育是必需的。拟南芥叶片表皮毛的细胞壁表面会出现突起，称为乳突。在这里，我们发现玻璃毛突变体 glh2 的表皮毛乳突密度比野生型大约低 11 倍。这种表型是由于拟南芥中介体亚基 16 的突变所致。MED16 定位于表皮毛的细胞核内，这与中介体在转录中的作用一致。在 glh2 突变体中，表皮毛发育报告基因 ETR2pro::GUS 和 GL2pro::GUS 的表达模式以及 GL2 转录本水平没有改变。在中介体尾部模块的其他亚基的可用 T-DNA 插入系的筛选中，发现 med2、med14 和 med15a 突变体中存在玻璃状表皮毛表型。这些数据表明，中介体复合物对于参与表皮毛乳突发育的基因的表达是必需的。
