Hormonal interaction in controlling apical dominance in soybeans

1971 ◽  
Vol 49 (9) ◽  
pp. 1727-1731 ◽  
Author(s):  
A. Ali ◽  
R. A. Fletcher
Keyword(s):  
Apical Dominance ◽  
Indoleacetic Acid ◽  
Inhibitory Effect ◽  
Benzyl Adenine ◽  
Intact Plants ◽  
Hormonal Interaction ◽  
Meristematic Activity ◽  
Bud Growth ◽  
Soybean Plants ◽  
Cut Surface

Growth of cotyledonary buds in soybean plants is controlled by an interaction between hormones and is dependent on age of the plant and meristematic activity of the buds. Indoleacetic acid (IAA) applied to the cut surface of decapitated 7-day-old plants does not inhibit the growth of buds which are actively undergoing mitosis. Growth is inhibited, however, when IAA is applied in combination with benzyl-adenine(BA) and this inhibitory effect is minimized by gibberellic acid (GA). In 16-day-old plants where mitosis in the buds has ceased IAA alone inhibits bud growth. In both 7- and 16-day-old decapitated plants, application of GA, alone or in combination with BA promotes growth of the buds. Inhibited buds have two peroxidase isoenzymes with pronounced activity. The activity of one of these decreases when the buds are released from dominance. Benzyladenine applied directly to inhibited buds initiates growth in 16-day-old intact plants and this growth is further enhanced when GA is applied 48 h after BA treatment. The enhanced growth by GA is prevented if 5-fluorouracil (5-FU) or 5-fluorodeoxyuridine (5-FDU) are applied before but not after the GA treatment. These results indicate that the hormones have a sequential role in releasing buds from apical dominance.

SOME RESPONSES OF ETIOLATED SEEDLINGS OF PISUM SATIVUM L. TO APPLIED 3-INDOLEACETIC ACID IN RELATION TO APICAL DOMINANCE

1965 ◽  
Vol 43 (1) ◽  
pp. 29-38 ◽  
Author(s):  
I. G. MacQuarrie
Keyword(s):  
Apical Dominance ◽  
Cell Expansion ◽  
Reducing Sugars ◽  
Indoleacetic Acid ◽  
Dry Weight ◽  
Pisum Sativum L ◽  
Pea Seedlings ◽  
Etiolated Seedlings ◽  
Bud Growth ◽  
The Relationship

Effects of decapitation and treatment with indoleacetic acid (IAA) were studied in etiolated pea seedlings. The relationship between epicotyl swelling and bud growth inhibition was examined and found to be incomplete: concentrations of IAA which totally inhibit bud growth induce marked epicotyl swelling, but a lower concentration (5 p.p.m.) was shown to induce swelling without affecting bud growth. Swelling is a result of a change in polarity of cell expansion; the time of this change was unaffected by increasing the IAA concentration. Large increases in fresh and dry weight accompany the swelling.In mature (non-swelling) epicotyls treated with IAA, this substance tends to prevent the loss of reducing sugars brought about by decapitation. It is suggested that decapitation and IAA application affect the nutritional status of the epicotyl, and that this effect must be considered in constructing hypotheses dealing with apical dominance.

Hormonal regulation of apical dominance in soybeans

1970 ◽  
Vol 48 (11) ◽  
pp. 1989-1994 ◽  
Author(s):  
A. Ali ◽  
R. A. Fletcher
Keyword(s):  
Acetic Acid ◽  
Gibberellic Acid ◽  
Apical Dominance ◽  
Hormonal Regulation ◽  
Indole Acetic Acid ◽  
Direct Application ◽  
Lateral Buds ◽  
Physiological Stage ◽  
Bud Growth ◽  
Cut Surface

Hormonal regulation of apical dominance in soybeans is dependent on the physiological stage of the lateral buds. In 7-day-old plants the cotyledonary buds are in an active state of mitosis and the application of a single hormone, gibberellic acid (GA) is effective in releasing the buds whilst indole acetic acid (IAA) is ineffective in inhibiting the buds of decapitated plants. In 16-day-old plants in which mitosis in the cotyledonary buds had ceased, a combination of both benzyladenine (BA) and GA was required for bud growth. BA initiated mitosis and GA promoted elongation. Application of IAA to the apical cut surface of these plants was effective in maintaining the inhibition of cotyledonary buds, and this inhibition could be overcome by a direct application of BA and GA to the inhibited buds. This study has shown that the growth of the inhibited cotyledonary buds in soybeans is regulated not only by auxins but by an interaction between auxins, cytokinins, and gibberellins. The effectiveness of any one of these hormones in inhibiting or promoting growth of the buds is dependent on the age of the plant.

Apical Dominance in Rhizomes of Quackgrass (Elytrigia repens): Inhibitory Effect of Scale Leaves

Weed Science ◽  
1989 ◽  
Vol 37 (5) ◽  
pp. 680-687 ◽  
Author(s):  
J. Mason Robertson ◽  
John S. Taylor ◽  
K. Neil Harker ◽  
Robert N. Pocock ◽  
Edward C. Yeung
Keyword(s):  
Apical Dominance ◽  
Inhibitory Effect ◽  
Axillary Buds ◽  
Aqueous Extracts ◽  
Leaf Removal ◽  
Initial Development ◽  
Leaf Material ◽  
Elytrigia Repens ◽  
Promotive Effect ◽  
Bud Growth

Surgical experiments were conducted on cultured five-node apical rhizome segments of quackgrass. Removal of scale leaves promoted an initial burst of growth within the axillary buds but did not support the continued growth of buds as effectively as removal of the rhizome apex. Replacement of detached scale leaves over denuded buds temporarily repressed the promotive effect of scale leaf removal. Aqueous extracts of scale leaf material inhibited apical growth in rhizome segments but did not inhibit bud growth. Anatomical sections revealed that removal of scale leaves promoted development of buds: cells enlarged, vascular tissues differentiated, and new nodes began to form within 4 days of the removal of scale leaves. It is suggested that scale leaves contribute to apical dominance by inhibiting the initial development of axillary buds.

Sugars, hormones, and environment affect the dormancy status in underground adventitious buds of leafy spurge (Euphorbia esula)

Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Wun S. Chao ◽  
Marcelo D. Serpe ◽  
James V. Anderson ◽  
Russ W. Gesch ◽  
David P. Horvath
Keyword(s):  
Seasonal Changes ◽  
Inhibitory Effect ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
Naphthaleneacetic Acid ◽  
Intact Plants ◽  
Axillary Meristems ◽  
Bud Growth ◽  
Root Buds ◽  
Ga Biosynthesis

Signals from both leaves and apical or axillary meristems of leafy spurge are known to inhibit root bud growth. To test the hypothesis that carbohydrates and growth regulators affect root bud growth, decapitated leafy spurge plants were hydroponically treated with glucose, sucrose, gibberellic acid (GA), abscisic acid (ABA), 1-naphthaleneacetic acid (NAA), 6-benzylaminopurine (BA), and a GA biosynthesis inhibitor, paclobutrazol. Both glucose and sucrose caused suppression of root bud growth at concentrations of 30 mM. The inhibitory effect of sucrose was counteracted by GA at 15 μM. In contrast, BA, ABA, NAA, and paclobutrazol inhibited root bud growth at concentrations as low as 1, 2, 1, and 16 μM, respectively. Sugar and starch levels were also determined in root buds at various times after decapitation. Buds of intact plants contained the highest level of sucrose compared with buds harvested 1, 3, and 5 d after decapitation. To determine how seasonal changes affect root bud dormancy, growth from root buds of field-grown plants was monitored for several years. Root buds of field-grown leafy spurge had the highest level of innate dormancy from October to November, which persisted until a prolonged period of freezing occurred in November or early December. Our data support the hypothesis that carbohydrates may be involved in regulating dormancy status in root buds of leafy spurge.

The Effect of Auxin on Sprouting in Poison Ivy

Weed Science ◽  
1970 ◽  
Vol 18 (2) ◽  
pp. 199-201
Author(s):  
J. P. Sterrett ◽  
C. L. Foy ◽  
S. W. Bingham
Keyword(s):  
Oxidation Product ◽  
Apical Dominance ◽  
Indoleacetic Acid ◽  
Enzyme Preparations ◽  
Stump Sprouting ◽  
Poison Ivy ◽  
Cut Surface ◽  
Stump Sprouts

Experiments were conducted on poison ivy (Rhus radicans L.) to determine the effect of auxin on the formation of sprouts. Stump sprouting occurred where poison ivy propagules were decapitated. The influence of the shoot could be replaced by applying indoleacetic acid (hereinafter referred to as IAA) in lanolin paste to the cut surface of the stump. When the paste was removed after inhibiting stump sprouting for a month, sprouts formed within 35 days. This evidence supports the apical dominance theory of stump sprouting. When IAA-2-14C in lanolin was applied to the cut surface of the root stump, autoradiographs showed that 14C activity was concentrated where the majority of stump sprouts would develop, and chromatography of an extract indicated the presence of an auxin oxidation product of IAA. Dialyzed enzyme preparations from poison ivy stumps oxidized IAA in a Warburg apparatus which demonstrated that an IAA oxidizing system was present.

Inhibition of cambial activity in Abies balsamea by internal water stress: role of abscisic acid

1975 ◽  
Vol 53 (24) ◽  
pp. 3041-3050 ◽  
Author(s):  
C. H. A. Little
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Indoleacetic Acid ◽  
Stomatal Closure ◽  
Abies Balsamea ◽  
Cambial Activity ◽  
Inhibitory Effect ◽  
Internal Water ◽  
Endogenous Aba

In experiments with attached and detached shoots of balsam fir, Abies balsamea L., synthetic (±)abscisic acid (ABA) (1) reduced photosynthesis and transpiration by inducing stomatal closure, (2) inhibited indoleacetic acid (IAA) - induced cambial activity in photosynthesizing and non-photosynthesizing shoots, and (3) inhibited the basipetal movement of [14C]IAA. Neither gibberellic acid nor kinetin counteracted the inhibitory effect of (±)ABA on IAA-induced cambial activity. In addition it was demonstrated that increasing the internal water stress increased the level of endogenous ABA in the phloem–cambial region of bark peelings and decreased the basipetal movement of [14C]IAA through branch sections. On the basis of these findings it is proposed that internal water stress inhibits cambial activity, partly through increasing the level of ABA; the ABA acts to decrease the provision of carbohydrates and auxin that are required for cambial growth.

Dormancy regulation: hormonal interaction in maple (Acer platanoides)

1969 ◽  
Vol 47 (7) ◽  
pp. 1165-1169 ◽  
Author(s):  
A. E. DeMaggio ◽  
J. A. Freeberg
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Acid Treatment ◽  
Acer Platanoides ◽  
Sterile Culture ◽  
Hormonal Interaction ◽  
Bud Growth ◽  
Short Days ◽  
Gibberellic Acid Treatment

Whole buds and excised apices (bud scales removed) from dormant trees of Acer platanoides grow in sterile culture in long days but have different responses to gibberellic acid treatment. Bud growth is stimulated by the hormone in long and short days but apices are unaffected. Abscisic acid inhibits not only gibberellin-stimulated bud growth but also the photoperiodically stimulated growth of apices.

Isolation and identification of lateral bud growth inhibitor, indole-3-aldehyde, involved in apical dominance of pea seedlings

2002 ◽  
Vol 61 (7) ◽  
pp. 863-865 ◽  
Author(s):  
Eri Nakajima ◽  
Hiroshi Nakano ◽  
Kosumi Yamada ◽  
Hideyuki Shigemori ◽  
Koji Hasegawa
Keyword(s):  
Apical Dominance ◽  
Growth Inhibitor ◽  
Isolation And Identification ◽  
Pea Seedlings ◽  
Lateral Bud ◽  
Bud Growth

Studies on the growth and development of Agropyron repens: interacting effects of humidity, calcium, and nitrogen on growth of the rhizome apex and lateral buds

1987 ◽  
Vol 65 (7) ◽  
pp. 1427-1432 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Apical Dominance ◽  
Water Status ◽  
Dry Weight ◽  
Apical Growth ◽  
High Humidity ◽  
N Supply ◽  
Lateral Buds ◽  
Low Humidity ◽  
Bud Growth ◽  
Agropyron Repens

A previous investigation of apical dominance in the rhizome of Agropyron repens showed that keeping the rhizome in a high humidity promoted the outgrowth of the lateral buds but strongly inhibited the growth of the rhizome apex. A study of these related responses demonstrated that the inhibition of apical growth was not prevented by excision of the lateral buds and was also induced when only the apex of the rhizome received the high humidity treatment. The necrotic lesions that developed in the arrested apices and the reduction of apical inhibition produced by various Ca treatments indicated that the inhibition of apical growth was caused by Ca deficiency. When the rhizome apex was exposed to low humidity, a localized high-humidity treatment of the lateral buds did not release the buds from apical dominance in low-N rhizomes but strongly promoted bud growth at a higher N level. When growth of the buds was induced at low humidity by increasing the N supply, the increase in bud weight was preceded by an increase in the water content of the bud when expressed on a dry weight basis. These results agree with those of previous investigations and suggest that the interacting effects of N and humidity on the water status of the buds may play a significant role in the mechanism of apical dominance.

Lateral bud growth on excised stem segments: effect of the stem

1975 ◽  
Vol 53 (3) ◽  
pp. 243-248 ◽  
Author(s):  
Carol A. Peterson ◽  
R. A. Fletcher
Keyword(s):  
Sucrose Solution ◽  
Apical Part ◽  
Endogenous Auxin ◽  
Cell Divisions ◽  
Cotyledonary Nodes ◽  
Lateral Buds ◽  
Lateral Bud ◽  
Bud Growth ◽  
Soybean Plants ◽  
Stem Segments

Lateral buds at the cotyledonary nodes of soybean plants grown under the conditions used in this study usually remain inhibited. These buds grow when the apical part of the plant is removed. They will grow, but less strongly, when the roots as well as the apex of the plant are removed and the basal end of the cut stem is placed in a mineral salt solution. Bud growth is further diminished by decreasing the length of stem left attached to the bud. The cotyledon is essential for bud growth on plant segments maintained in nutrient solution, but it can be replaced by a 1% sucrose solution during the early days of bud growth. Buds which are completely detached from the stem and placed in 1% sucrose do not elongate, but a small number of cell divisions are detectable, indicating that the early events of the release from inhibition have occurred. Buds elongate when they are apically or centrally located on stem segments. Increasing the length of the attached stem segments increases the growth of the buds. Additions of the cytokinin benzyladenine to plants causes a dramatic increase in bud growth when buds are attached to stem segments but does not stimulate growth of buds without stem segments. It is concluded that benzyladenine alone will not substitute for a factor(s) present in the stem which is necessary for bud growth. Increasing stem lengths above buds located at the basal ends of segments inhibits bud growth. It is suggested that this may be due to an accumulation of endogenous auxin at the site of the buds.

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