Seedling containers

In 1926 Frits Went, a student in the Netherlands, detected that the tips of wheat seedlings contained a substance that caused the seedlings to bend toward the light. The identity of the substance, which was given the name auxin from the Greek auxein (meaning "to increase"), was unknown. A few years later it was shown that auxin was indole-3-acetic acid (I A A). Today, four natural auxins are known. Besides IAA there are indole-3-butyric acid, phenylacetic acid, and 4-chloroindole-3-acetic acid. (It is quite interesting to find a chlorinated aromatic substance as a natural substance. It is synthesized... 

Although the seeds of Catharanthus roseus lack alkaloids, young seedlings contain several dozen alkaloids. TTiese alkaloids disappear after about 3 weeks and reappear at 8 weeks (Robinson, 1974) in the intermediate period, alkaloids are absent from the plants. 

In angiosperms dark-grown etiolated seedlings contain some carotenoids, but their synthesis is stimulated by exposure to light. However, this process is coupled with chloroplast development, and therefore carotenoid synthesis may not be independent. Other examples are cited by Rau (1976). 

Germination is effective in lowering the content of phytic acid in flaxseed. After 8 days of germination, flax seedlings contained 27% lower phytic acid than that present in ungerminated seeds (Wanasundara, 1995). Degradation of phytic acid for the release of phosphorus for metabolic requirements may account for this observation. 

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