The Foolish Seedling Disease
Botany online 1996-2004. No further update, only historical document of botanical science!
Gibberellins
In 1926 studied the Japanese E. KUROSAWA a rice disease that is known as the ‘foolish seedling’-disease in Japan. The plants grow extremely fast, look spindly and pale and break off easily. KUROSAWA detected that the reason for this abnormal growth is a substance that is secreted by a parasitic fungi (Fusarium moniliforme = Gibberella fujikuroi). It was termed gibberellin.
During the thirties was gibberellin isolated and crystallized by Japanese scientists from Tokyo (YABUTA and SUMIKI ), though it was almost forgotten in the following years. In 1956 isolated C. A. WEST and B. O. PHINNEY a gibberellin from Phaseolus vulgaris and other plants, thus showing that these compounds are far-spread in the plant kingdom. Today are more than 110 different gibberellins known (GA1, GA2,....GA3, GA4.....GA110) that differ only little chemically but very much in their biological activities.
Roughly 30 percent of all known gibberellins are biologically active. All higher plants contain presumably at least one, but usually several active and inactive gibberellins that exist in different concentrations depending on the respective tissue.
Gibberellins are diterpenoids derived from four isoprenoid units forming a system of four rings. It is distinguished between gibberellins of 19 and such of 20 C-atoms. The twentieth C-atom is not part of the four rings but belongs to a side chain (CH3 in GA12, CH2OH in GA15, CHO in GA19 or COOH in GA28). Both enumeration and the illustration below show, how the single structures differ.
Young, growing meristematic cauline tissue, apical root cells, young fruits, as well as unripe or germinating seeds are all rich in gibberellins. In sun flowers is the gibberellin content highest in the young leaves and in the uppermost internodes while it decreases continuously towards the basal leaves and internodes.
Gibberellin content and
Gibberellins
In 1926 studied the Japanese E. KUROSAWA a rice disease that is known as the ‘foolish seedling’-disease in Japan. The plants grow extremely fast, look spindly and pale and break off easily. KUROSAWA detected that the reason for this abnormal growth is a substance that is secreted by a parasitic fungi (Fusarium moniliforme = Gibberella fujikuroi). It was termed gibberellin.
During the thirties was gibberellin isolated and crystallized by Japanese scientists from Tokyo (YABUTA and SUMIKI ), though it was almost forgotten in the following years. In 1956 isolated C. A. WEST and B. O. PHINNEY a gibberellin from Phaseolus vulgaris and other plants, thus showing that these compounds are far-spread in the plant kingdom. Today are more than 110 different gibberellins known (GA1, GA2,....GA3, GA4.....GA110) that differ only little chemically but very much in their biological activities.
Roughly 30 percent of all known gibberellins are biologically active. All higher plants contain presumably at least one, but usually several active and inactive gibberellins that exist in different concentrations depending on the respective tissue.
Gibberellins are diterpenoids derived from four isoprenoid units forming a system of four rings. It is distinguished between gibberellins of 19 and such of 20 C-atoms. The twentieth C-atom is not part of the four rings but belongs to a side chain (CH3 in GA12, CH2OH in GA15, CHO in GA19 or COOH in GA28). Both enumeration and the illustration below show, how the single structures differ.
Young, growing meristematic cauline tissue, apical root cells, young fruits, as well as unripe or germinating seeds are all rich in gibberellins. In sun flowers is the gibberellin content highest in the young leaves and in the uppermost internodes while it decreases continuously towards the basal leaves and internodes.
Gibberellin content and