Identification of gibberellins in the rice plant and quantitative changes of gibberellin A19 throughout its life cycle

Kurogochi, Shin; Murofushi, Noboru; Ota, Yasuo; Takahashi, Nobutaka

doi:10.1007/bf00388230

Cited by 67 publications

(25 citation statements)

References 9 publications

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“…13,14). In (2) and Oryza (8); and it has been suggested that GA19 serves as a pool of inactive substrate for the synthesis through GA20 of the active GA1 (10). GA67 was identified from cotyledons, consistent with its presence in seeds (6), and thus is likely to have been synthesized during seed maturation.…”

Section: Discussionmentioning

confidence: 83%

“…The sample was redissolved in EtOAc and transferred to a 1 cm diameter column of 4 g of activated silica (Woelm, 32-100 ,um) which was then eluted with 10 mL volumes of EtOAc. Fractions containing the radioactive internal standards were combined and rerun twice on new columns to further reduce mass before being purified by C18 HPLC: 10 utm uBondapak C18, 10 In experiment 3, 1.0 g of freeze-dried hypocotyls from seedlings from each ethylene treatment (94, 94, 98, and 78 hypocotyls, respectively, from each of the 0, 5, 50, and 500 nL L' treatments) was extracted in 80% MeOH. Internal standards of [3H]GA1 (1440 Bq) and [3H]GA4 (1370 Bq) were added.…”

Section: Ga Treatmentmentioning

confidence: 99%

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Ethylene-Mediated Regulation of Gibberellin Content and Growth in Helianthus annuus L.

Pearce

Reid²,

Pharis³

1991

Plant Physiol.

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Elongation of hypocotyls of sunflower can be promoted by gibberellins (GAs) and inhibited by ethylene. The role of these hormones in regulating elongation was investigated by measuring changes in both endogenous GAs and in the metabolism of exogenous [3H]-and [2H2]GA2o in the hypocotyls of sunflower (Helianthus annuus L. cv Delgren 131) seedlings exposed to ethylene. The major biologically active GAs identified by gas chromatography-mass spectrometry were GA,, GA19, GA2o, and GA44. In hypocotyls of seedlings exposed to ethylene, the concentration of GA,, known to be directly active in regulating shoot elongation in a number of species, was reduced. Ethylene treatment reduced the metabolism of [3H]GA2o and less [2H2]GA1 was found in the hypocotyls of those seedlings exposed to the higher ethylene concentrations. However, it is not known if the effect of ethylene on GA20 metabolism was direct or indirect. In seedlings treated with exogenous GA, or GA3, the hypocotyls elongated faster than those of controls, but the GA treatment only partially overcame the inhibitory effect of ethylene on elongation. We conclude that GA content is a factor which may limit elongation in hypocotyls of sunflower, and that while exposure to ethylene results in reduced concentration of GA, this is not sufficient per se to account for the inhibition of elongation caused by ethylene.Seedlings of most, if not all, plant species produce ethylene as well as GAs.2 Gibberellins promote elongation of stem cells directly through the action of GA, in several species (e.g. 13, 14), while ethylene inhibits elongation of stems but promotes radial growth. It has been shown that GA treatment will reverse the effect of ethylene on elongation (e.g. 21) and that ethylene inhibits GA-induced elongation (e.g. 3).As part of ongoing studies on the role of GAs and other hormones in control of growth and development in Helianthus (4, 5, 17), we have investigated GA metabolism and its interaction with ethylene in sunflower seedlings. We have used ethylene as a tool to modify elongation in our investigation of GA metabolism.We describe the effect of GA and ethylene treatment on elongation of hypocotyls of sunflower seedlings, and report In experiment 2, to test the effect of exogenous GA on elongation, seeds were sown in Terragreen (a baked clay medium) in 10 cm pots and grown in Perspex chambers for fumigation with ethylene from the time of planting (15). The chambers were illuminated with fluorescent Gro-Lux lights (320 ,umol m-2 s-') during a 16 h day. The temperature was 26°C during the day, and 14°C at night. The seedlings were watered automatically with half-strength Hoaglands solution for 45 s h-1. The CO2 concentration in the chambers was maintained at 350 ,uL L'. After 7 d, seedlings were treated with GA3. Three days later, seedlings were harvested and hypocotyl length was measured. This experiment was repeated, and later repeated again with GA3 and GA, applied to plants grown in conditions slightly modified from those described above (i.e. ma...

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Section: Discussionmentioning

confidence: 83%

Section: Ga Treatmentmentioning

confidence: 99%

Ethylene-Mediated Regulation of Gibberellin Content and Growth in Helianthus annuus L.

Pearce

Reid²,

Pharis³

1991

Plant Physiol.

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“…GA192 and GA20 have been identified from bamboo (Phyllostachys edulis) (13); GA, and GA19 from rice (Oryza sativa) (9); GA1, GA19, and GA29 from sugarcane (Saccharum spp.) (8); and eight GA from the early 13-OH pathway have been identified from maize (Zea mays) (3,4).…”

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confidence: 99%

Identification of Endogenous Gibberellins from Sorghum

Rood

Larsen²,

Mander³

et al. 1986

Plant Physiol.

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Gibberellins (GA) Al, A19, and A20 were identified in shoot cylinders containing the apical meristems from sorghum (Sorghum bicolor L.). Extracts were purified by sequential SiO2 partition chromatography and reversed-phase C18 high performance liquid chromatography and biologically active (dwarf rice cv Tan-ginbozu microdrop assay) fractions were subjected to gas chromatography-selected ion monitoring. Based on the use of PHIGA and 12Hj(d2)GA internal standards, amounts of GA,, GA1,, and GA2n were estimated to be 0.7, 8.8, and 1.5 namograms per gram dry weight of tissue, respectively.Gibberellins characteristic of the early 13-OH biosynthetic pathway have been previously identified from a number of C4 and tropical grasses. GA192 and GA20 have been identified from bamboo (Phyllostachys edulis) (13); GA, and GA19 from rice (Oryza sativa) (9); GA1, GA19, and GA29 from sugarcane (Saccharum spp.) (8); and eight GA from the early 13-OH pathway have been identified from maize (Zea mays) (3, 4). Further, GA1 has also been identified from a number of other cereal grasses (6). The physiological similarities between maize and sorghum (Sorghum bicolor) and the evolutionary relationship between sorghum and other C4 and tropical grasses suggests that sorghum might also contain GA characteristic of the early 13-OH metabolic pathway. The present study was initiated to identify the endogenous GA of sorghum, a commercially important C4 cereal for which GA-like substances have been previously reported (1) but not characterized. (12) were added to the extract (i.e. 0.5 ng GA, and 13.3 ng GA20). MATERIALS AND METHODSThe methanol was removed in vacuo at 35°C after the addition of0.5 M phosphate buffer (pH 8.0). The buffered aqueous extract was slurried with poly-N-PVP and filtered. The pH was raised to 9.0 with NaOH and Chl was removed by two extractions with diethyl ether. The pH was then reduced to 3.0 with HC1 and the sample extracted 3 times with equal volumes of H20-saturated ethyl acetate. The ethyl acetate was frozen at -40C the ice removed by filtering, and the ethyl acetate was subsequently removed in vacuo at 35TC. The acidic, ethyl acetate-soluble extract was purified on columns of charcoal:celite (1:1) eluted with acetone:water (80:20). This was followed by stepwise-elution Sio2 partition chromatography (2, 16), and detection of GA-like activity using the dwarf rice cv Tan-ginbozu microdrop assay (11) modified by using 0.5 gl application droplets and 48 h of incubation. Biologically active Sio2 fractions were then chromatographed on reversed-phase C18 HPLC (7,15). Flow and solvent parameters were as previously described (7,15), although the gradient from 0 to 70% MeOH was run over 60 rather than 30 min. Eighty 1-min fractions were collected and subsequently bioassayed at 3 dilutions (1/200, 1/400, 1/800 aliquots). Bioassay results after SiO2 partition chromatography (see Fig. 1) are expressed as moving three-point averages to reduce experimental "noise," although the chromatographic peaks are broadened in so doin...

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“…In the series of studies on hormonal regulation of the growth and development of rice, Kurogochi et al 1) have identified GAl and GA19 in vegetative tissues of rice, cv. Nihonbare (japonica type).…”

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confidence: 99%

“…Each sample was extracted with acetone-water (4: 1) and the extract was submitted to solvent fractionation to give an acidic ethyl acetate (AE) fraction. The AE fraction was purified by HPLC using three different types of columns: (1) LiChrosorb RP-18, (2) Shodex A-80l (GPC) and (3) Nucleosil 5N (CH 3 )2.J) The GA fractions obtained by HPLC purifications were derivatized into methyl ester trimethylsilyl ether (Me ester TMSi ether) or trimethylsilyl ester trimethylsilyl ether (TMSi ester TMSi ether) and subjected to GCjSIM analysis. The analysis resuIts are shown in Tables I and II. In immature seeds, five 13-0H GAs, namely GA19, GA20, GA29, GA44 and GAS3' were identified.…”

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confidence: 99%