【摘要】 通过构建以GUS为报告基因的生长素响应表达载体的遗传转化,开展了棉花生长素的原位研究。经棉花叶片瞬时表达分析,证实该报告基因在棉花中有效。采用农杆菌子房注射法将该报告基因转化至湘杂棉21号后,经筛选检测,获得了3株阳性转基因棉花植株。对转基因棉花胚珠及花原基进行的GUS检测表明在棉花受粉前2 d(-2 DAP,Dayafter pollination)至受粉后2 d(2 DAP)的胚珠发育期间,棉花胚珠表面生长素水平呈现"V"形变化过程,且在受粉2 DAP后,GUS染色更集中分布在分化了的纤维细胞中。说明在棉花受粉前的胚珠发育早期,表层细胞中含有较高浓度水平的生长素,维持着表层细胞的持续分裂。而在胚珠表层纤维细胞分化期生长素浓度降低,GUS着色变浅。受精后,纤维细胞开始伸长突起,伸长的纤维细胞中有更强的GUS着色,证明分化了的纤维细胞中具有较高浓度的生长素分布,这可以促进纤维细胞的伸长生长。胚珠表层相邻细胞的低水平的生长素对棉花纤维细胞的分化突起可能起关键作用。对花原基的GUS染色观察,生长素主要集中分布在分化的花组织细胞分裂活跃的区域,表明生长素在促进花器官的发育和器官建成方面有重要作用。更多还原

【Abstract】 A GUS reporter gene under the control of repeat auxin responsible elements(AuxRe) in the plant expression vector pBI121(pBI121-DR5::GUS) was constructed for carry out an in situ auxin study in cotton.The auxin responsibility of the reporter gene is first confirmed by the cotton leaf transient transformation analysis.The agrobacterium-mediated ovary injections transformation was then applied to transform the report gene into cotton variety "Hunan hybrid cotton 21".Three transgenic cotton plants were identified by kanamycin screening and PCR detection.The transgenic cotton ovule and flower primordia were subjected to GUS staining to illustrate the auxin distribution byin situ during the ovule and flower development.The GUS staining showed that from -2 DAP to 2 DAP of the bloom of the flower,integument of the ovule auxin level varies as "V" shape.At two days after the pollination the GUS staining is heavier in the differentiated fiber cells.It indicated the ovule out cells maintained a high level of auxin to favor integument cell dividing.Butthe auxin decreased in the integument cells to facilitate the cell differentiation during the fiber cells differentiation stage(ovule integument cell division ceased).The GUS staining ofthe auxin concentrating in the fiber cells after the fiber cell differentiated is stronger.Different levels of auxin in adjacent integument cells may play a key role during cotton fiber cell differentiation.And once the fiber cell differentiation finished,the high level of auxin can promote the rapid elongation of cells.The GUS staining of the transgenic flower buds showed the auxin concentrated in primodium of flower organs as well as in the early developing ovules,which indicates that auxin active in cotton flower organ identity and promoting its morphogenesis.更多还原