Bierfreund Nicole M, Tintelnot Stefanie, Reski Ralf, Decker Eva L
University of Freiburg, Schaenzlestrsse, Freiburg, Germany.
J Plant Physiol. 2004 Jul;161(7):823-35. doi: 10.1016/j.jplph.2003.12.010.
Auxin-induced gene expression is described for a variety of different genes including the SAUR-, Aux/IAA- and GH3-families, members of which have been found in seed plants. The precise function of GH3-like proteins in plant development is not well characterised yet. Mutant analysis in Arabidopsis thaliana indicates a possible role for GH3-like proteins in connecting auxin and light signal transduction. Here, we report the isolation of three different GH3-like homologues from a lower land plant, the moss Physcomitrella patens. Two of the GH3-like homologues were chosen for further characterisation. Both genes are expressed in gametophytic tissues, with expression starting very early in moss development. Knockout plants were generated and analysed. In comparison to white-light growth, cultivation of the wild type and knockout plants under red-light conditions resulted in a delay in gametophytic tissue development. The leafy moss plants displayed an elongated phenotype. Growth delay and elongation were even stronger under far-red light conditions. No obvious differences between wild type and knockout plants could be detected under the examined conditions, indicating functional redundancy of the two genes.
生长素诱导的基因表达已在多种不同基因中得到描述，包括SAUR、Aux/IAA和GH3家族，这些家族的成员已在种子植物中被发现。GH3样蛋白在植物发育中的精确功能尚未得到很好的表征。拟南芥中的突变分析表明，GH3样蛋白在连接生长素和光信号转导中可能发挥作用。在此，我们报告从一种低等陆生植物——小立碗藓中分离出三种不同的GH3样同源物。选择其中两种GH3样同源物进行进一步表征。这两个基因均在配子体组织中表达，在苔藓发育早期就开始表达。我们构建并分析了基因敲除植株。与白光下生长相比，野生型和基因敲除植株在红光条件下培养导致配子体组织发育延迟。叶状苔藓植物表现出细长的表型。在远红光条件下，生长延迟和伸长更为明显。在所检测的条件下，未检测到野生型和基因敲除植株之间存在明显差异，表明这两个基因存在功能冗余。
