莲胚发育与核酸、蛋白质含量的变化

Nucleic Acid and Protein Contents in Relation to Embryogenesis of Lotus

莲胚发育达到最大鲜重(开花后21d)前,胚轴和子叶的DNA,RNA都持续增长。开花13d后,蛋白、淀粉等贮藏物质显著积累,核酸增长速度加快。成熟胚轴的DNA和RNA含量很高,而子叶中积累大量的淀粉、可溶性糖和蛋白质。发育前期胚乳的生长速度较快,开花后16d左右鲜重和物质积累达到高峰。胚生长后期胚乳逐渐败育,贮藏物质和结构物质都减少,膨大的子叶逐步取代了胚乳的地位。 莲胚生物大分子物质含量的模式属于双子叶植物类型。讨论了莲胚细胞多倍化的问题。

In order to understand the characteristicsof embryogenesis of Nelumbo nucifera Gaertnand to explore the biochemical developmentalproperties of various types of plants, thegrowth curves of axis, cotyledon and endo-sperm and the changes of DNA, RNA,protein, soluble sugar ahd starch contents inthem during embryogenesis were studied bymicrobiochemical analysis. The levels of DNA and RNA in axisand cotyledon rose continuoulsy until the em-bryo reached the maximum fresh weight.On the 13th day from the starting of anthesis,the reserved substances, such as protein,starch, etc., accumulated significantly, and atthe same time the amount of nucleic acid in-creased rapidly. The contents of DNA andRNA were very high in mature axis, while alarge amount of starch, soluble sugar andprotein was accumulated in cotyledons. Atthe early developmental stage, the endospermsgrew rapidly and the accumulation of freshweight and substances reached its maximumabout on the 16th day. At the later stage,the endosperms degenerated gradually, andthe reserved and structural substances de-creased. The expanded cotyledons eventual-ly replaced the endosperms. It was shown that the pattern of changeof the contents of biomacromolecular substan-ces in lotus resembled those of dicots. The characteristics of lotus embryogenesisand the polyploidization of the embryo cellswere discussed.