Department of Plant Physiology, Agricultural University, Arboretumlaan 4, 6703 BD, Wageningen, The Netherlands.
Planta. 1979 Oct;146(5):559-66. doi: 10.1007/BF00388832.
Under humid conditions, both bi- and trinucleate pollen species incorporate, on the average, very low amounts of leucine, e.g., 0.4 pmol min(-1)mg pollen(-1). During germination in vitro, however, the two types of pollens greatly differ in their capacity for protein synthesis.Binucleate pollen species such as Typha, which are characterized by slow respiration in humid air and prolonged lag periods during germination in vitro, contain large amounts of monoribosomes at dehiscence. Polyribosomes are formed soon after the pollen is wetted in the germination medium, and a considerable incorporation of leucine is initiated after 10-15 min. More rapidly respiring, binucleate pollen showing a short lag period, such as Tradescantia, may already contain many polysomes at dehiscence and incorporate leucine within 2 min of germination. However, rapidly respiring, trinucleate Compositae pollen contains very limited amounts of ribosomal material and never attains any substantial level of incorporation. Cycloheximide completely inhibits both protein synthesis and tube emergence and growth in the slowly respiring, binucleate pollen species. The more rapidly respiring types are less dependent on protein synthesis, while germination of the phylogenetically advanced, trinucleate Compositae pollen proceeds completely independently. It is concluded that the level of phylogenetic advancement of the male gametophyte is characterized by its overall state of metabolic development at dehiscence rather than by the number of its generative cells.
在潮湿的条件下，双核和三核花粉平均吸收的亮氨酸很少，例如 0.4 pmol min(-1)mg 花粉(-1)。然而，在体外萌发过程中，这两种花粉在蛋白质合成能力上存在很大差异。二核花粉，如香蒲，其特征是在潮湿空气中呼吸缓慢，体外萌发时延迟期较长，在开裂时含有大量单核糖体。多核糖体在花粉在萌发介质中湿润后很快形成，并且在 10-15 分钟后开始大量掺入亮氨酸。呼吸更快、延迟期较短的二核花粉，如紫露草，在开裂时可能已经含有许多多核糖体，并在萌发后 2 分钟内开始掺入亮氨酸。然而，呼吸更快的三核菊科花粉仅含有非常有限量的核糖体物质，并且永远不会达到任何实质性的掺入水平。环己亚胺完全抑制了呼吸缓慢的双核花粉物种中的蛋白质合成和管的出现和生长。呼吸更快的类型对蛋白质合成的依赖性较小，而系统发育上更先进的三核菊科花粉的萌发则完全独立进行。因此，可以得出结论，雄性配子体的系统发育进化程度与其开裂时的整体代谢发育状态有关，而不是与其生殖细胞的数量有关。
