Re: what is gibberellic acid (GA-3) used for?

Ive been keeping abreast of all the technical info that has been passing
back and forth here on Ga-3, so let me try to explain a little bit more
about it in laymans terms. Quote " Gibberelic Acid- 3 is a
naturally-occurring plant growth regulator which may cause a variety of
effects including the stimulation of seed germination in some cases. Ga-3
is not a panacea. While many ordinarily difficult seeds will readily
germinate with the use of GA-3, it may kill other seeds, or produce
elongation in others" J.L. HUDSON SEEDSMAN. Mr Hudson sells GA-3 and will
provide you the instructions on how to use it, and it is quite easy!
Contact him by snail mail.
Star Route 2, Box 337, La Honda California, 94020 also an excellent read is
Norman Denos Seed Germination, Theory & practice . In his book he lists
hundreds of varieties of plants and their germination requisites, alot with
Ga-3 and this is for the home gardener explained in easy terms.
Recluse Gardens









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> From: Hortus <HORTUS@worldnet.att.net>
> To: Seeds List <seeds-list@eskimo.com>
> Subject: what is gibberellic acid (GA-3) used for? 
> Date: Tuesday, October 20, 1998 2:24 PM
> 
> Your questions about GA are quite complex
> 
> I recommend that you go to the extensive information at
> the Plant Hormones web site:
> 
> http://www.plant-hormones.bbsrc.ac.uk/
> and
> http://www.lars.bbsrc.ac.uk/plantsci/gas.html
> 
> The following information is copied from the later page
> 
> And if you are reallllly interested search their mail archive!
> 
> regards
> Joel Kroin
> 
> --------------------------
> 
> Gibberellins (GAs) are a group of diterpenoid acids that function as
plant
> growth regulators inflencing a range of developmental processes in higher
> plants including stem elongation, germination, dormancy, flowering, sex
> expression, enzyme induction and leaf and fruit senescence. The origin of
> research into gibberellins can be traced to Japanese plant pathologists
who
> were investigating the causes of the "bakanae" (foolish seedling) disease
> which seriously lowered the yield of rice crops in Japan, Taiwan and
> throughout the Asian continent.
> Symptoms of the disease are pale yellow, elongated seedlings with slender
> leaves and stunted roots. Severely diseased plants die whereas plants
with
> slight symptoms survive but produce poorly developed grain, or none at
all.
> 
> Bakanae is now easily prevented by treatment of seeds with fungicides
prior
> to sowing. The first paper on the cause of bakanae was published in 1898
by
> Shotaro Hori who demonstrated that the symptoms were induced by infection
> with a fungus belonging to the genus Fusarium, probably Fusarium
> heterosporium Nees.
> 
> 
> 
> Characteristic elongated rice seedling caused by bakanae
> 
> In 1912, Sawada published a paper in the Formosan Agricultural Review
> entitled "The Diseases of Crops in Taiwan" in which he suggested that the
> elongation in rice seedlings infected with bakanae fungus might be due to
a
> stimulus derived from fungal hyphae.
> 
> Subsequently, Eiichi Kurosawa (1926) found that culture filtrates from
dried
> rice seedlings caused marked elongation in rice and other sub-tropical
> grasses. He concluded that bakanae fungus secretes a chemical that
> stimulates shoot elongation, inhibits chlorophyll formation and
suppresses
> root growth.
> 
> Although there has been controversy among plant pathologists over the
> nomenclature of bakanae fungus, in the 1930s, the imperfect stage of the
> fungus was named Fusarium moniliforme (Sheldon) and the perfect stage,
> Gibberella fujikuroi (Saw.) Wr. by H.W. Wollenweber. The terms
"Fujikuroi"
> and "Saw." in Gibberella fujikuroi (Saw.) Wr. were derived from the names
of
> two distinguished Japanese plant pathologists, Yosaburo Fujikuro and
> Kenkichi Sawada.
> 
> Teijiro Yabuta initiated work on the isolation of the active component
using
> the fungal strains provided by Kurosawa. In 1934, Yabuta isolated a
> crystalline compound from the fungal culture filtrate that inhibited
growth
> of rice seedlings at all concentrations tested. The structure of the
> inhibitor was shown to be 5-n-butylpicolinic acid or fusaric acid. The
> formation of fusaric acid in culture filtrates was suppressed by changing
> the composition of the culture medium. As a result, a non-crystalline
solid
> was obtained from the culture filtrate that stimulated the growth of rice
> seedlings. This compound was named gibberellin by Yabuta in 1935; the
first
> use of the term "gibberellin" in the scientific literature.
> 
> In 1938, Yabuta and his associate Yusuke Sumiki finally succeeded in
> crystallizing a pale yellow solid to yield gibberellin A and gibberellin
B
> (The names were subsequently interchanged in 1941 and the original
> gibberellin A was found to be inactive.) Determination of the structure
of
> the active gibberellin was hampered by a shortage of pure crystalline
> sample. By current standards the productivity of their fungal strain was
> extremely poor and they did not know that their sample of gibberellin A
was
> not pure, but a mixture of structurally-related gibberellins.
> 
> In the United States, the first research on gibberellins began after the
> Second World War by a research unit at Camp Dietrick, Maryland. In 1950,
> John E. Mitchell reported optimal fermentation procedures for the fungus,
as
> well as the effects of fungal extracts on the growth of bean (Vicia
> faba)seedlings(Mitchell & Angel 1951). Work also began at the Northern
USDA
> Regional Research Laboratories in Peoria, Illinois in the USA using the
> strain provided by Mitchell. Large scale fermentations were carried out
with
> the purpose of producing pure gibberellin A for agricultural uses but
> initial fermentations were inactive.
> 
> In 1951, Sumiki visited the United States and met Frank H. Stodola. After
> returning to Japan he sent new cultures to the USA but these also proved
> inactive. The problem was traced to the lack of magnesium in the culture
> medium and good yields of gibberellin were obtained when the culture
medium
> was supplemented with magnesium sulphate. The physical properties of
> gibberellin isolated from these fermentations were found to be
surprisingly
> different from those reported by the Japanese and the new compound was
named
> gibberellin-x. (Stodola et al., 1955).
> 
> At about the same time in the UK, a team of researchers ( Philip Curtis,
> Brian Cross, John Grove, Jake MacMillan and Paddy Mulholland) at Akers
> Research Laboratories (ICI) isolated a new gibberellin which was given
the
> name "gibberellic acid".This compound had physical properties different
from
> the Japanese gibberellin A(Curtis & Cross, 1954). Samples were exchanged
> between Stodola and Grove and "gibberellic acid" and gibberellin-X were
> found to have identical chemical and physical properties and the name
> gibberellic acid was accepted by both groups. A structure for gibberellic
> acid was proposed in 1956 but later revised see Grove 1961.
> 
> In 1955, members of Sumuki group, (Takahashi et al.) succeeded in
separating
> the methyl ester of gibberellin A into three components, from which
> corresponding free acids were obtained and named gibberellins A1, A2, and
> A3. Gibberellin A3 was found to be identical to gibberellic acid. In
1957,
> Takahashi et al. isolated a new gibberellin named gibberellin A4 as a
minor
> component from the culture filtrate.
> 
> In the mid 1950s, evidence that gibberellins were naturally occurring
> substances in higher plants began to appear in the literature. Using
> techniques that had been used to isolate gibberellins from the fungus,
> Margaret Radley at ICI in the UK demonstrated the presence of
> gibberellin-like substances in higher plants. In the USA, the first
reports
> of a gibberellin-like substance in maize came from Bernard Phinney et al
> using dwarf maize mutants to assay for activity in plant extracts. This
was
> followed by the isolation of crystalline gibberellin A1, A5, A6 and A8
from
> runner bean (Phaseolus multiflorus) (MacMillan et al. 1958, 1959,
> 1960,1962). The original samples from these isolations are now on display
at
> Long Ashton.
> 
> In the 1960s the number of gibberellins reported in the literature
isolated
> from fungal and plant origins rapidly increased. In 1968, J. MacMillan &
N.
> Takahashi reached an agreement that all gibberellins should be assigned
> numbers as gibberellin A1-x, irrespective of their origin. Over the past
20
> years using modern analytical techniques many more gibberellins have been
> identified. At the present time the current number of gibberellins
> identified is 94.
> 
> For a more detailed description of the history of gibberellins please see
> Phinney, B.O.(1983) and Tamura, S. (1990)
> 
> Steve Croker (steve.croker@bbsrc.ac.uk)
>
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