Agrocampus Ouest, Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), SFR 149 QUASAV, PRES UNAM, 49045, Angers, France.
Plant Cell Rep. 2012 Nov;31(11):2015-29. doi: 10.1007/s00299-012-1313-1. Epub 2012 Aug 17.
We reported the cloning of a rose DELLA gene. We obtained transgenic Pelargonium lines overexpressing this gene which presented several phenotypes in plant growth, root growth, flowering time and number of inflorescences. Control of development is an important issue for production of ornamental plant. The plant growth regulator, gibberellins (GAs), plays a pivotal role in regulating plant growth and development. DELLA proteins are nuclear negative regulator of GA signalling. Our objective was to study the role of GA in the plant architecture and in the blooming of ornamentals. We cloned a rose DELLA homologous gene, RoDELLA, and studied its function by genetic transformation of pelargonium. Several transgenic pelargonium (Pelargonium × domesticum 'Autum Haze') lines were produced that ectopically expressed RoDELLA under the control of the 35S promoter. These transgenic plants exhibited a range of phenotypes which could be related to the reduction in GA response. Most of transgenic plants showed reduced growth associated to an increase of the node and branch number. Moreover, overexpression of RoDELLA blocked or delayed flowering in transgenic pelargonium and exhibited defects in the root formation. We demonstrated that pelargonium could be used to validate ornamental gene as the rose DELLA gene. RoDELLA overexpression modified many aspects of plant developmental pathways, as the plant growth, the transition of vegetative to floral stage and the ability of rooting.
我们报道了玫瑰 DELLA 基因的克隆。我们获得了该基因过表达的天竺葵转基因品系，这些品系在植物生长、根系生长、开花时间和花序数量方面表现出多种表型。控制发育是生产观赏植物的一个重要问题。植物生长调节剂赤霉素（GAs）在调节植物生长和发育中起着关键作用。DELLA 蛋白是 GA 信号的核负调节剂。我们的目标是研究 GA 在观赏植物的植物结构和开花中的作用。我们克隆了一个玫瑰 DELLA 同源基因 RoDELLA，并通过对天竺葵的遗传转化来研究其功能。产生了几个过表达 RoDELLA 的转基因天竺葵（天竺葵×杂种）系，该基因在 35S 启动子的控制下异位表达。这些转基因植物表现出一系列表型，这些表型可能与 GA 反应的降低有关。大多数转基因植物的生长受到抑制，节间和分枝数量增加。此外，RoDELLA 的过表达阻止或延迟了转基因天竺葵的开花，并表现出根系形成缺陷。我们证明了天竺葵可用于验证观赏基因，如玫瑰 DELLA 基因。RoDELLA 的过表达改变了植物发育途径的许多方面，如植物生长、营养生长向生殖生长的转变以及生根能力。
