With the completion of the Populus genome sequence in 2006,the study on functional genomics in Populus has become a major task.Establishment of Populus mutant population is an essential approach for forestry functional genomics study.The activation tagging is a promising and powerful method to construct mutant library of Populus and to further discover new gene and elucidate its function now.A novel T-DNA activation tagging pCAS05 was constructed for forest functional genomics in this study.We could select conveniently and easily transgenic plants by spraying Basta because bar gene is constructed in this vector as a selection marker.Moreover,we could also construct a large scale mutant library in Populus by this activation tagging because of effectively selection of bar gene.
穗的外露(穗颈长度)对水稻的产量有重要影响.穗颈过短,会造成包颈穗,影响水稻的结实率;穗颈过长,容易造成倒伏或穗颈折断,从而影响水稻的生产和产量.赤霉素(gibberellin,GA)在植物茎的伸长调控中起着重要作用.本研究对水稻赤霉素类受体家族基因OsGRL1(Gibberellin receptor like 1)的功能进行了探究,发现该基因在水稻穗颈长度和产量性状方面具有重要的调控作用.表达分析表明,OsGRL1在茎、叶鞘及茎顶端组织中高表达,不受外源GA的诱导.亚细胞定位分析表明,与已知的水稻GA受体蛋白OsGID1定位于细胞核中不同,OsGRL1蛋白定位在细胞膜上,且不随外源GA的诱导而改变.与野生型相比,OsGRL1敲除突变体表现出穗颈伸长、籽粒变小和千粒重降低的表型,而过表达转基因株系穗颈缩短、籽粒变大且千粒重增加.进一步研究发现,OsGRL1基因突变使GA信号转导通路中抑制基因SLR1的表达下调,提高了突变体对GA敏感性.因此,OsGRL1通过调控GA信号转导通路基因的表达而调节水稻穗颈伸长和产量,在育种中具有潜在的应用价值.
