POLLEN TUBE‐SYNERGID INTERACTIONS IN PROBOSCIDEA LOUISIANICA (MARTINEACEAE)
POLLEN TUBE‐SYNERGID INTERACTIONS IN PROBOSCIDEA LOUISIANICA (MARTINEACEAE)
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路易斯安那长鼻科（马丁科）的花粉管-协同相互作用
DOI：
10.1002/j.1537-2197.1978.tb06160.x
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发表时间：
1978
影响因子：
3
通讯作者：
H. L. Mogensen
中科院分区：
文献类型：
--
作者：
H. L. Mogensen
本文研究了受精前至授粉后48小时的长吻瓢虫（Proboscidea louisianica）助细胞的超微结构。结果表明，在花粉管到达胚囊之前，助细胞的细胞质就开始退化，并且总是这个助细胞接受花粉管尖端和它的释放。另一种助细胞（持久性助细胞）在整个研究期间保持不变。观察到花粉管来源的多糖囊泡与花粉管壁融合，并有助于退化助细胞的细胞壁形成。授粉后48小时，一个胚珠中有两个花粉管进入珠孔，但只有第一个花粉管穿过退化的助细胞并正常排出。第二个花粉管紧靠宿存助细胞，但没有进入或排出。在另一个例外的情况下（授粉后18小时），一个花粉管已经增长的珠孔的长度，但没有放电，或进入任何助细胞。胚珠的两个助细胞都是完整的。它的结论是助细胞和花粉管细胞质退化是这两个细胞之间的一个非常具体的相互作用的结果，这种退化可能是一个先决条件，正常的花粉管入口和排放到胚囊，并为雄配子转移到卵和中央细胞。
The ultrastructure of the synergids ofProboscidea louisianicawas investigated from just before fertilization until 48 hr after pollination. It was found that the cytoplasm of one synergid consistently begins to degenerate before arrival of the pollen tube at the embryo sac, and that it is always this synergid which receives the pollen tube tip and its discharge. The other synergid (persistent synergid) remained unchanged throughout the study period. Polysaccharide vesicles of pollen tube origin were observed fusing with the pollen tube wall as well as contributing to cell wall formation of the degenerate synergid. In one ovule (48 hr after pollination) two pollen tubes had entered and grown the length of the micropyle, but only the first tube penetrated the degenerate synergid and discharged normally. The second pollen tube was abutting against the persistent synergid, but had not entered or discharged. In another exceptional case (18 hr after pollination), a pollen tube had grown the length of the micropyle, but did not discharge, or enter either synergid. Both synergids of this ovule were observed to be completely intact. It is concluded that synergid and pollen tube cytoplasmic degeneration is the result of a very specific interaction between these two cells and that this degeneration is probably a prerequisite for normal pollen tube entrance and discharge into the embryo sac, and for male gamete transfer to the egg and central cell.