APETALA1 启动子驱动AtIPT4 在转基因拟南芥中表达导致花和花器官发育异常

细胞分裂素对拟南芥(Arab idopsis thal iana)花分生组织细胞的分裂和分化具有重要作用。本研究利用APETALA1(AP1)特异启动子在花分生组织和第1、2轮花器官中表达细胞分裂素合成酶(isopentyl trans ferase, IPT)基因IPT4, 研究细胞分裂素对花和花器官发育的影响。在pAP1::IPT4转基因植株中出现了花密集和花器官数目增多等现象。原位杂交和GUS组织染色结果发现, 在pAP1::IPT4转基因植株中, 花分生组织特征决定基因LEAFY (LFY)与花器官特征决定基因AP1、PISTILLATA (PI )和AGAMOUS (AG)的表达量均有不同程度的提高。研究结果表明在拟南芥中表达pAP1::IPT4影响其花和花器官的正常发育。

Expression of AtIPT4 Gene Under the Control of APETALA1 Promoter Results in Abnormal Flower and Floral Organ Development

The plant hormone cytokinin plays important roles in cell division and differentiation of floral meristem. To investigate the relation between cytokinin and the flower, as well as floral organ development, we investigated in Arabidopsis the expression of the cytokinin biosynthetic gene IPT4 under control of the promoter of APETALA1 (AP1) in the floral meristem and outer two whorls of floral organs. Transgenic plants with pAP1::IPT4 showed abnormal phenotypes, including acompact flower arrangement and increased number of flower organs. In situ hybridization and GUS staining analyses revealed the up-regulation of LEAFY (LFY) , AP1, PISTILLATA (PI) and AGAMOUS (AG) in pAP1::IPT4 transgenic plants. Thus, the expression of AtIPT4 under control of AP1 mediates the development of flower and floral organs in part via regulating the expression of LFY and floral organ identity genes.