Relationship between floral development and transcription levels of LEAFY and TERMINAL FLOWER 1 homologs in Japanese pear (Pyrus pyrifolia Nakai) and quince (Cydonia oblonga Mill.)
Relationship between floral development and transcription levels of LEAFY and TERMINAL FLOWER 1 homologs in Japanese pear (Pyrus pyrifolia Nakai) and quince (Cydonia oblonga Mill.)
复制标题
DOI：
10.2503/jjshs.76.294
复制
发表时间：
2007-10-01
影响因子：
--
通讯作者：
Yonemori, Keizo
中科院分区：
文献类型：
--
作者：
Esumi, Tomoya;Tao, Ryutaro;Yonemori, Keizo
采用实时荧光定量RT-PCR和原位杂交技术，研究了LEAFY（LFY）和TFL 1（TFL 1）同源基因在梨和木瓜花蕾中的时空表达，以阐明它们在苹果亚科果树花和花序发育中的作用。选择日本梨和温柏是因为它们在无性生殖上非常接近，但发展出不同的花序结构。日本梨的花分化开始于6月下旬至7月上旬，在日本大坂，形成一个总状花序，约有8朵花，而在木瓜的花分化发生在10月下旬至11月，在日本长野，每个花芽形成一朵单瓣花。LFY同源物在两个物种中的表达水平在花分化阶段增加，并在花器官分化阶段后的花分生组织中保持在相对较高的水平。与此相反，TFL 1同源物的表达水平在这两个物种都很高，在营养阶段的芽，但显着下降之前，花分化。日本梨TFL 1同源物在花分化前的顶端分生组织的亚表皮层中表达，而温柏的TFL 1同源物在顶端分生组织和叶原基的表皮层中表达。我们讨论了可能参与maloid LFY和TFL 1同源物在触发花分化，以及参与不同的空间表达模式的TFL 1同源物的花序结构的日本梨和木瓜。
Using real-time reverse-transcription polymerase chain reaction (real-time RT-PCR) and in situ hybridization, we investigated the temporal and spatial expression of LEAFY (LFY) and TERMINAL FLOWER 1 (TFL1) homologs in Japanese pear (Pyrus pyrifolia) and quince (Cydonia oblonga) buds, in order to elucidate their roles in the flower and inflorescence development of fruit trees in the subfamily Maloideae (Rosaceae). Japanese pear and quince were selected because they are very close phylogenetically but develop distinct inflorescence architectures. Floral differentiation in Japanese pear began in late June to early July in Osaka, Japan, forming a raceme inflorescence with about eight flowers, whereas that in quince took place from late October to November in Nagano, Japan, forming a solitary flower in each floral bud. LFY homolog expression levels in both species increased at the floral differentiation stage and remained at relatively high levels in flower meristems after the flower organ differentiation stage. In contrast, TFL1 homolog expression levels in both species were high in vegetative-stage buds, but decreased significantly just before floral differentiation. Japanese pear TFL1 homologs were expressed in the subepidermal layer of the apical meristem before floral differentiation, whereas those of quince were expressed in the epidermal layer of the apical meristem and leaf primordia. We discuss the possible involvement of maloid LFY and TFL1 homologs in triggering floral differentiation, as well as the involvement of the different spatial expression patterns of TFL1 homologs in the inflorescence architectures of Japanese pear and quince.