Effect of Ethylene and Gibberellic Acid on Auxin Synthesis in Plant Tissues

Valdovinos, Jack G.; Ernest, Leland C.; Henry, Egbert W.

doi:10.1104/pp.42.12.1803

Cited by 54 publications

(38 citation statements)

References 13 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Earlier reports on the breakdown of auxin by Coleus tissue are in agreement with this conclusion (10,32).…”

Section: Resultssupporting

confidence: 80%

“…Auxin Formation. The effect of the ethylene pretreatment on auxin formation by apical bud tissue was studied following procedures reported earlier (30,32). The enzyme breis were prepared as described in "Auxin Destruction."…”

Section: Methodsmentioning

confidence: 99%

“…The manner in which the gas influences levels of diffusible auxin in plant cells is not entirely clear. In a brief report (32), the authors presented some evidence correlating low levels of diffusible auxin in ethylene-treated tissue with decreased auxin formation by enzyme breis from the same tissue. The studies have been expanded in an attempt to correlate several facets of auxin metabolism-auxin biosynthesis, conjugation, and destruction-with levels of extractable and diffusible auxin in the leaf and stem tissue.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Regulation of Auxin Levels in Coleus blumei by Ethylene

Ernest

Valdovinos

1971

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

The effects of ethylene in lowering levels of auxin diffusing through plant tissues are well known (1, 6-8, 12, 16, 20, 22, 32 Corporation, Washington, West Virginia. The canister was constructed of degreased galvanized pipe (10 X 40 cm) with circles of screen wire in drilled pipe caps fitted with laboratory gas outlets. Teflon tape rather than oil was applied to the pipe threads to allow easy disassembly for refilling and to prevent contamination of the Purafil.In the case of plants placed in plastic bags, temperatures inside the bags were maintained at 24 C during the light phase.Unless indicated otherwise, plants were exposed to ethylene at concentrations of 25 or 100 bld/liter for an 18-hr period.The 18-hr period consisted of 6 hr of light, 8 hr of darkness, and light during the remainder of the pretreatment period.Auxin Transport. Following procedures described earlier (31), we measured auxin transport through the uppermost internode of Coleus stems. Stem segments 5 mm in length were removed from the treated and untreated plants, coated with a ring of Vaseline to prevent surface transport, and placed on glass slides. One percent agarose cylinders of a volume of 23 ,ul containing IAA-l-"4C, 5 mg/liter (32,600 cpm average per block), served as auxin donors on the physiological apical end and similar cylinders without IAA served as receivers. During the transport period the sections were in a nearly vertical position with the donor above and the receiver below. After 5 hr in a moist chamber kept in the dark, the donor and receiver cylinders and the stem sections (macerated) were placed in counting vials separately or in groups of five and frozen. The radioactivity was assayed with a Nuclear-Chicago liquid scintillation counting system following procedures described in an earlier paper (33). A second counting medium which proved to be more convenient for counting the radioactivity in aqueous samples was used in later experiments. This medium consisted of Spectrograde toluene containing the fluors PPO and POPOP mixed with Triton X-100 in a ratio of 7:6.

show abstract

“…Earlier reports on the breakdown of auxin by Coleus tissue are in agreement with this conclusion (10,32).…”

Section: Resultssupporting

confidence: 80%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Regulation of Auxin Levels in Coleus blumei by Ethylene

Ernest

Valdovinos

1971

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Changes in cell sensitivity have largely been attributed to changes in the auxin concentration of the cells in this region (7,16). Several workers (9,11,13) have suggested that ethylene participates in lowering the auxin concentration in the cell separation region and, hence, in changing the sensitivity of these cells, through its reported effects on auxin transport (9,11), destruction (22,31), and synthesis (36). Of these three, the effect of ethylene on auxin transport has been most closely correlated with the abscission process.…”

Section: Resultsmentioning

confidence: 99%

“…Spectrofluorometric determinations (35) Ethylene apparently alters auxin synthesis, conjugation, or destruction in the leaf blade, since the total extractable auxin content, as indicated above, is reduced by 65% following a 48-hr exposure to ethylene (unpublished data). Effects on synthesis are suggested by the results of two studies (18,36) indicating that ethylene inhibits the conversion of tryptophan to IAA in Coleus while effects on destruction are suggested by the enhanced IAA oxidase activities observed in cotton leaves following ethylene treatment (22). Added to these potential auxin lowering actions of ethylene is the observed fact that ethylene reduces auxin transport in the veinal tissues of the leaf blade in essentially the same manner as it does in the petiole (unpublished data).…”

Section: Resultsmentioning

confidence: 99%

Abscission: The Initial Effect of Ethylene Is in the Leaf Blade

Beyer¹

1975

Plant Physiol.

View full text Add to dashboard Cite

The leaf blade of cotton (Gossy-piu7n hirsutum L. cv. Stoneville 213) was investigated as the initial site of ethylene action in abscission. Ethylene applied at 14 ul/l to intact 3-week-old plants caused abscission of the third true leaf within 3 days. However, keeping only the leaf blade of this leaf in air during ethylene treatment of the rest of the plant completely prevented its abscission for up to 7 days. This inhibition of abscission was apparently the result of continued auxin production in the blade since (a) the application of an auxin transport inhibitor to the petiole of the air-treated leaf blade restored ethylene sensitivity to the leaf in terms of abscission; (b) repeated applications of naphthaleneacetic acid to the leaf blade of the third true leaf, when the entire plant was exposed to ethylene, had the same preventive effect on abscission of this leaf as keeping its leaf blade in air; and (c) the inhibitory effect of ethylene on auxin transport in the petiole, which is reduced by auxin treatment, was also reduced by placing the leaf blade in air.The reverse treatment of exposing only the leaf blade of the third true leaf to 14 ,l/l of ethylene, while the rest of the plant was kept in air, also did not cause abscission for up to 5 days. Auxin transport in the petioles of these leaves, however, was inhibited over 80% within 2 days and this effect presumably accounted for their increased sensitivity to ethylene during the subsequent exposures of the whole leaf to the gas.These results suggest that an initial and essential function of applied ethylene in abscission is to reduce the amount of auxin transported out of the leaf blade. This reduction together with the inhibitory effect of ethylene on auxin transport in the petiole reduces the auxin level at the abscission zone to a point where the cells in this region become responsive to the more direct action of the gas (e.g., enzyme induction and secretion). This sequence of events accounts for the lack of abscission unless ethylene is applied to both the leaf blade and the abscission zone.

show abstract

Effect of Ethylene on Cellular Differentiation in Etiolated Pea Seedlings

Apelbaum

Fisher

Burg

1972

American J of Botany

View full text Add to dashboard Cite

Ethylene (50 ppm) and 2,4‐D (1 mm) inhibit xylogenesis and completely prevent fiber lignification in the third internode of etiolated pea seedlings (Pisum sativum var. Alaska) during 96–240 hr of treatment. When ethylene is removed after 72 hr, normal differentiation resumes; thus the gas causes no irreversible damage to the cells. A combined treatment with 50 ppm ethylene and 50 μm 2,4‐D or treatment with 1 mm 2,4‐D alone causes inhibition similar to that observed with 50 ppm ethylene, and 50 μm 2,4‐D is partially effective. The inhibition of xylogenesis and fiber lignification caused by 2,4‐D is partly or wholly due to auxin‐induced ethylene production.

show abstract

Effect of Ethylene and Gibberellic Acid on Auxin Synthesis in Plant Tissues

Cited by 54 publications

References 13 publications

Regulation of Auxin Levels in Coleus blumei by Ethylene

Regulation of Auxin Levels in Coleus blumei by Ethylene

Abscission: The Initial Effect of Ethylene Is in the Leaf Blade

Effect of Ethylene on Cellular Differentiation in Etiolated Pea Seedlings

Contact Info

Product

Resources

About