Apical dominance in Pssu-ipt-transformed tobacco

Geuns, Jan; Smets, R; Struyf, Tom; Prinsen, Els; Valcke, Roland; Onckelen, Harry Van

doi:10.1016/s0031-9422(01)00338-7

Cited by 23 publications

(19 citation statements)

References 28 publications

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“…This corresponded to a strong outgrowth after the release from apical dominance and is consistent with reports of an increased cytokinin content in upper axillary buds at the release from apical dominance (Geuns et al, 2001;Tanaka et al, 2006).…”

Section: Measurement Of Auxin (Iaa) and Cytokininsupporting

confidence: 91%

Hormonal and Genetic Regulation of Axillary Bud Outgrowth in Chrysanthemum Morifolium During Floral Initiation

Dierck¹,

Keyser²,

Riek³

et al. 2015

Acta Hortic.

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Shoot branching or the outgrowth of axillary buds is a crucial aspect in the production and breeding of Chrysanthemum sp. The outgrowth of axillary buds is inhibited by the shoot apex through apical dominance. Central to this regulation is the interaction of the plant hormones auxin, cytokinin and strigolactone. In this research we aim to study the hormonal and genetic regulation of apical dominance and axillary bud outgrowth in a cut flower cultivar of Chrysanthemum. For this we combined measurements of axillary bud outgrowth with UPLC-MS/MS quantification of auxin and cytokinin levels and RT-qPCR analysis of two genes involved in the regulation of branching. The cultivar used displayed apical dominance during vegetative growth. A release from apical dominance occurs during floral initiation with outgrowth and elongation of shoots under the apex. The outgrowth of axillary buds after release from apical dominance was preceded by decreased auxin levels in the shoot apex, axillary buds and stem and increased cytokinin levels in the axillary buds. RT-qPCR showed a decreased expression of the local bud outgrowth regulator BRC1 preceding the release from apical dominance at the time of floral initiation.

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Section: Measurement Of Auxin (Iaa) and Cytokininsupporting

confidence: 91%

Hormonal and Genetic Regulation of Axillary Bud Outgrowth in Chrysanthemum Morifolium During Floral Initiation

Dierck¹,

Keyser²,

Riek³

et al. 2015

Acta Hortic.

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“…In the bud2 mutant plant, the homeostasis of polyamines is altered, leading to an obvious increase in putrescine and decreases in spermidine and spermine, which in turn leads to an altered plant morphology [4]. In recent years, studies on the biosynthesis of polyamines have indicated that polyamines are involved in a variety of plant developmental processes [2, 5-8, 11, 71, 72], especially the formation of plant architecture including shoot apical dominance [58]. However, the mechanism underlying polyamine action needs to be elucidated.…”

Section: Discussionmentioning

confidence: 99%

“…To investigate whether the loss of apical dominance of bud2 plants involves auxin action, we examined the hypocotyl elongation at higher temperature and the lateral shoot development after decapitation of wild-type and bud2 mutant plants [43,57,58]. Identification of temperatureinduced hypocotyl elongation is a simple and rapid assay in the study of an auxin-mediated growth response [59].…”

Section: The Bud2 Plant Shows Altered Hypocotyl Elongation and Lateramentioning

confidence: 99%

The BUD2 mutation affects plant architecture through altering cytokinin and auxin responses in Arabidopsis

et al. 2010

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The ratio of auxin and cytokinin plays a crucial role in regulating aerial architecture by promoting or repressing axillary bud outgrowth. We have previously identified an Arabidopsis mutant bud2 that displays altered root and shoot architecture, which results from the loss-of-function of S-adenosylmethionine decarboxylase 4 (SAMDC4). In this study, we demonstrate that BUD2 could be induced by auxin, and the induction is dependent on auxin signaling. The mutation of BUD2 results in hyposensitivity to auxin and hypersensitivity to cytokinin, which is confirmed by callus induction assays. Our study suggests that polyamines may play their roles in regulating the plant architecture through affecting the homeostasis of cytokinins and sensitivities to auxin and cytokinin. IntroductionPolyamines, including diamine putrescine, triamine spermidine and tetraamine spermine, are low-molecularmass organic cations. They exist widely in all living organisms and are essential for their survival, because blocking of the biosynthesis of polyamines leads to lethal phenotypes in animals [1] and higher plants [2][3][4]. In higher plants, polyamines have been proposed to function in response to environmental stresses and in regulating growth and development [4][5][6][7][8][9][10][11]. Plant molecular and physiological studies over past decades have shown that higher plants defective in producing polyamines often have altered plant architecture, with reduced plant height or more branches in shoots and roots [4,[10][11][12][13]. However, the underlying mechanisms still remain largely elusive.Branches of higher plants originate from the axillary meristems (AMs) of shoots, and formation of a branch generally consists of the initiation of a new AM and its subsequent outgrowth. However, an AM may arrest its growth under some conditions, forming a dormant bud. The dormant buds will release their outgrowth once they sense a permissible environmental or developmental signal. In many plant species, axillary buds become dormant due to the inhibiting effects of the primary shoot apex on the outgrowth of AMs, a phenomenon known as 'apical dominance'. Auxin was first regarded as a direct regulator in this process [14], a notion strengthened thereafter by physiological studies on decapitated shoot apices [15][16][17], and by analyzing auxin biosynthesis, transport and signaling [18][19][20][21][22][23][24][25][26][27][28][29] in plants. However, when radiolabelled auxin was applied to a decapitated stump, the outgrowth of axillary buds was inhibited even though radiolabelled auxin was not found to accumulate in axillary buds, suggesting an indirect suppression effect of auxin on the AM outgrowth [28,30] and the presence of second messengers.Cytokinin has been proposed as a second messenger that mediates the action of auxin in controlling the apical dominance, because it promotes the outgrowth of lateral buds when directly applied to buds [31]. Although an antagonistic role of auxin and cytokinin in the regulation of apical dominance has been postu...

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Section: Introductionmentioning

confidence: 99%

“…Previous observations revealed that polyamines may be involved in a variety of plant developmental processes, such as cell division, root initiation, somatic embryogenesis, xylogenesis, flower development, fruit ripening and senescence [3]. Recent studies have indicated that polyamines also affect the formation of plant architecture, such as internode elongation [10,11], root branching [12] and shoot apical dominance [13].The plant polyamine biosynthetic pathway is relatively simple [14]. Putrescine is derived either from ornithine catalyzed by ornithine decarboxylase (ODC) or from arginine through several steps catalyzed by arginine decarboxylase (ADC), agmatine iminohydrolase and N-carbamoylputrescine amidohydrolase.…”

mentioning

confidence: 99%

BUD2, encoding an S-adenosylmethionine decarboxylase, is required for Arabidopsis growth and development

et al. 2006

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Polyamines are implicated in regulating various developmental processes in plants, but their exact roles and how they govern these processes still remain elusive. We report here an Arabidopsis bushy and dwarf mutant, bud2, which results from the complete deletion of one member of the small gene family that encodes S-adenosylmethionine decarboxylases (SAMDCs) necessary for the formation of the indispensable intermediate in the polyamine biosynthetic pathway. The bud2 plant has enlarged vascular systems in inflorescences, roots, and petioles, and an altered homeostasis of polyamines. The double mutant of bud2 and samdc1, a knockdown mutant of another SAMDC member, is embryo lethal, demonstrating that SAMDCs are essential for plant embryogenesis. Our results suggest that polyamines are required for the normal growth and development of higher plants.Cell Research (2006) IntroductionPolyamines, including diamine putrescine, triamine spermidine and tetraamine spermine, are aliphatic nitrogen compounds distributed widely from bacteria to higher plants [1,2] and have been implicated to play important roles in growth and development [3]. At the cellular level, polyamines are organic cations, interacting with the macromolecules that possess anionic groups such as DNA, RNA, lipids and proteins, thereby influencing DNA conformation, gene expression and protein synthesis, and modulating enzyme activity. In higher plants, polyamines are able to affect membrane fluidity by binding to phospholipids in membrane [4] and mediate biotic and abiotic stress responses, such as pathogen infection, osmotic stress, potassium deficiency and wounding [5][6][7][8][9]. Previous observations revealed that polyamines may be involved in a variety of plant developmental processes, such as cell division, root initiation, somatic embryogenesis, xylogenesis, flower development, fruit ripening and senescence [3]. Recent studies have indicated that polyamines also affect the formation of plant architecture, such as internode elongation [10,11], root branching [12] and shoot apical dominance [13].The plant polyamine biosynthetic pathway is relatively simple [14]. Putrescine is derived either from ornithine catalyzed by ornithine decarboxylase (ODC) or from arginine through several steps catalyzed by arginine decarboxylase (ADC), agmatine iminohydrolase and N-carbamoylputrescine amidohydrolase. Spermidine and spermine are synthesized from putrescine through spermidine and spermine synthases (SPDS and SPMS) from the donor of decarboxylated S-adenosylmethionine (dcSAM), which is produced from S-adenosylmethionine (SAM) by the action of S-adenosylmethionine decarboxylase (SAMDC).Although application of inhibitors is very useful in studying the polyamine biosynthetic pathway and in ex- [11,[19][20][21][22][23][24]. However, no mutant defective in SAMDC has been reported yet, although SAMDC cDNAs were cloned and their transgenic plants have been generated [25][26][27][28][29]. In this paper, we report the isolation and characterization of an Arabidopsis...

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Apical dominance in Pssu-ipt-transformed tobacco

Cited by 23 publications

References 28 publications

Hormonal and Genetic Regulation of Axillary Bud Outgrowth in Chrysanthemum Morifolium During Floral Initiation

Hormonal and Genetic Regulation of Axillary Bud Outgrowth in Chrysanthemum Morifolium During Floral Initiation

The BUD2 mutation affects plant architecture through altering cytokinin and auxin responses in Arabidopsis

BUD2, encoding an S-adenosylmethionine decarboxylase, is required for Arabidopsis growth and development

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