Chen Jhun-Chen, Fang Su-Chiung
Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, 741, Taiwan.
Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan.
Plant Reprod. 2016 Jun;29(1-2):179-88. doi: 10.1007/s00497-016-0280-z. Epub 2016 Mar 25.
Pollen biology in P. aphrodite. Orchids have a distinct reproductive program. Pollination triggers ovule development and differentiation within flowers, and fertilization occurs days to months after pollination. It is unclear how pollen tubes travel through the developing ovaries during ovule development and when pollen tubes arrive at the mature embryo sac to achieve fertilization. Here, we report a robust staining protocol to image and record the timing of pollen germination, progressive growth of pollen tubes in ovaries, and arrival of pollen tubes at embryo sacs in Phalaenopsis aphrodite. The pollen germinated and pollen tubes entered the ovary 3 days after pollination. Pollen tubes continued to grow and filled the entire cavity of the ovary as the ovary elongated and ovules developed. Pollen tubes were found to enter the matured embryo sacs at approximately 60-65 days after pollination in an acropetal manner. Moreover, these temporal changes in developmental events such as growth of pollen tubes and fertilization were associated with expression of molecular markers. In addition, we developed an in vitro pollen germination protocol, which is valuable to enable studies on pollen tube guidance and tip growth regulation in Phalaenopsis orchids and possibly in other orchid species.
蝴蝶兰的花粉生物学。兰花有独特的繁殖程序。授粉触发花朵内胚珠的发育和分化，受精发生在授粉后数天至数月。目前尚不清楚在胚珠发育过程中花粉管如何穿过发育中的子房，以及花粉管何时到达成熟胚囊以实现受精。在此，我们报告了一种可靠的染色方案，用于成像和记录蝴蝶兰花粉萌发的时间、花粉管在子房中渐进生长的过程以及花粉管到达胚囊的时间。授粉后3天花粉萌发且花粉管进入子房。随着子房伸长和胚珠发育，花粉管持续生长并充满子房的整个腔室。发现花粉管在授粉后约60 - 65天以向顶方式进入成熟胚囊。此外，花粉管生长和受精等发育事件的这些时间变化与分子标记的表达相关。另外，我们开发了一种体外花粉萌发方案，这对于开展蝴蝶兰以及可能其他兰花物种的花粉管导向和顶端生长调控研究具有重要价值。
