scholarly journals MAX1 and MAX2 control shoot lateral branching in Arabidopsis

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1131-1141 ◽  
Author(s):  
Petra Stirnberg ◽  
Karin van de Sande ◽  
H. M. Ottoline Leyser
Keyword(s):  
Positional Cloning ◽  
Leaf Shape ◽  
Shoot Meristem ◽  
Axillary Shoot ◽  
Axillary Meristem ◽  
Axillary Shoots ◽  
Recessive Mutations ◽  
Lateral Shoots ◽  
Plant Shoots ◽  
Shoot Meristems

Plant shoots elaborate their adult form by selective control over the growth of both their primary shoot apical meristem and their axillary shoot meristems. We describe recessive mutations at two loci in Arabidopsis, MAX1 and MAX2, that affect the selective repression of axillary shoots. All the first order (but not higher order) axillary shoots initiated by mutant plants remain active, resulting in bushier shoots than those of wild type. In vegetative plants where axillary shoots develop in a basal to apical sequence, the mutations do not clearly alter node distance, from the shoot apex, at which axillary shoot meristems initiate but shorten the distance at which the first axillary leaf primordium is produced by the axillary shoot meristem. A small number of mutant axillary shoot meristems is enlarged and, later in development, a low proportion of mutant lateral shoots is fasciated. Together, this suggests that MAX1 and MAX2 do not control the timing of axillary meristem initiation but repress primordia formation by the axillary meristem. In addition to shoot branching, mutations at both loci affect leaf shape. The mutations at MAX2 cause increased hypocotyl and petiole elongation in light-grown seedlings. Positional cloning identifies MAX2 as a member of the F-box leucine-rich repeat family of proteins. MAX2 is identical to ORE9, a proposed regulator of leaf senescence (Woo, H. R., Chung, K. M., Park, J.-H., Oh, S. A., Ahn, T., Hong, S. H., Jang, S. K. and Nam, H. G. (2001) Plant Cell13, 1779-1790). Our results suggest that selective repression of axillary shoots involves ubiquitin-mediated degradation of as yet unidentified proteins that activate axillary growth.

The WUSCHEL gene is required for shoot and floral meristem integrity in Arabidopsis

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 87-96 ◽  
Author(s):  
T. Laux ◽  
K.F. Mayer ◽  
J. Berger ◽  
G. Jurgens
Keyword(s):  
Developmental Stages ◽  
Shoot Meristem ◽  
Wild Type ◽  
Recessive Mutations ◽  
Organ Identity ◽  
Flat Structures ◽  
Meristem Identity ◽  
Wus Gene ◽  
Floral Meristems ◽  
Shoot Meristems

Self perpetuation of the shoot meristem is essential for the repetitive initiation of shoot structures during plant development. In Arabidopsis shoot meristem maintenance is disrupted by recessive mutations in the WUSCHEL (WUS) gene. The defect is evident at all developmental stages and is restricted to shoot and floral meristems, whereas the root meristem is not affected. wus mutants fail to properly organize a shoot meristem in the embryo. Postembryonically, defective shoot meristems are initiated repetitively but terminate prematurely in aberrant flat structures. In contrast to wild-type shoot meristems, primordia initiation occurs ectopically across mutant apices, including the center, and often new shoot meristems instead of organs are initiated. The cells of wus shoot apices are larger and more vacuolated than wild-type shoot meristem cells. wus floral meristems terminate prematurely in a central stamen. Double mutant studies indicate that the number of organ primordia in the center of wus flowers is limited, irrespective of organ identity and we propose that meristem cells are allocated into floral whorl domains in a sequential manner. WUS activity also appears to be required for the formation of supernumerary organs in the center of agamous, superman or clavata1 flowers, suggesting that the WUS gene acts upstream of the corresponding genes. Our results suggest that the WUS gene is specifically required for central meristem identity of shoot and floral meristems to maintain their structural and functional integrity.

scholarly journals Genome-wide identification and characterization of GRAS transcription factors in tomato (Solanum lycopersicum)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3955 ◽  
Author(s):  
Yiling Niu ◽  
Tingting Zhao ◽  
Xiangyang Xu ◽  
Jingfu Li
Keyword(s):  
Gene Family ◽  
Solanum Lycopersicum ◽  
Stress Responses ◽  
Expression Patterns ◽  
Gene Families ◽  
Shoot Meristem ◽  
Axillary Shoot ◽  
Multiple Sequence ◽  
Genome Wide ◽  
First Time

Solanum lycopersicum, belonging to Solanaceae, is one of the commonly used model plants. The GRAS genes are transcriptional regulators, which play a significant role in plant growth and development, and the functions of several GRAS genes have been recognized, such as, axillary shoot meristem formation, radial root patterning, phytohormones (gibberellins) signal transduction, light signaling, and abiotic/biotic stress; however, only a few of these were identified and functionally characterized. In this study, a gene family was analyzed comprehensively with respect to phylogeny, gene structure, chromosomal localization, and expression pattern; the 54 GRAS members were screened from tomato by bioinformatics for the first time. The GRAS genes among tomato, Arabidopsis, rice, and grapevine were rebuilt to form a phylogenomic tree, which was divided into ten groups according to the previous classification of Arabidopsis and rice. A multiple sequence alignment exhibited the typical GRAS domain and conserved motifs similar to other gene families. Both the segmental and tandem duplications contributed significantly to the expansion and evolution of the GRAS gene family in tomato; the expression patterns across a variety of tissues and biotic conditions revealed potentially different functions of GRAS genes in tomato development and stress responses. Altogether, this study provides valuable information and robust candidate genes for future functional analysis for improving the resistance of tomato growth.

scholarly journals Micropropagation of Members of the Cactaceae Subtribe Cactinae

1990 ◽  
Vol 115 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Philip W. Clayton ◽  
John F. Hubstenberger ◽  
Gregory C. Phillips ◽  
S. Ann Butler-Nance
Keyword(s):  
Shoot Proliferation ◽  
Shoot Tip ◽  
Axillary Shoot ◽  
Axillary Shoots ◽  
Axillary Shoot Proliferation ◽  
Shoot Production ◽  
Series Of Experiments ◽  
Basal Media ◽  
Free Media ◽  
Shoot Tip Explants

Micropropagation of 11 rare or endangered cacti species belonging to the subtribe Cactinae was achieved by rooting of proliferated axillary shoots. Shoot tip explants were obtained from seedlings of Escobaria missouriensis D.R. Hunt, E. robbinsorum (Earle) D.R. Hunt, Sclerocactus spinosior (Engelm.) Woodruff & L. Benson, and Toumeya papyracantha (Engelm.) Br. & Rose, and from mature plants of Mammillaria wrightii Engelm., Pediocactus bradyi L. Benson, P. despainii Welsh & Goodrich, P. knowltonii L. Benson, P. paradinei B.W. Benson, P. winkleri Heil, and S. mesae-verdae (Boissevain) L. Benson. Three or four species were used in each of a series of experiments investigating the effects of basal media and auxin and cytokinin types and concentrations on axillary shoot proliferation. Low or no auxin but moderate to high cytokinin concentrations were required for axillary shoot production. All species rooted spontaneously on hormone-free media; however, several species rooted better on media containing auxin. All species were re-established in the greenhouse.

Papaya performance unaffected by lateral shoot pruning

1969 ◽  
Vol 82 (1-2) ◽  
pp. 63-68
Author(s):  
Bryan R. Brunner
Keyword(s):  
Field Experiments ◽  
Germplasm Collection ◽  
Axillary Shoot ◽  
Lateral Shoot ◽  
Axillary Shoots ◽  
Branch Number ◽  
Subsequent Performance ◽  
Date Fruit ◽  
Branch Development ◽  
Lateral Branches

The practice of axillary shoot removal in young (3 to 4 mo) trees of papaya cultivar Puerto Rico 6-65 was examined in field experiments in 1993 and 1995 to determine whether or not subsequent performance is affected. No significant differences were observed between pruned and unpruned plants for flowering date, fruiting date, fruit yield, days to virus infection or virus severity. Significant differences were observed between years for all variables. In an unpruned papaya germplasm collection of 40 genotypes planted in 1993 and 1995, 17 (43%) had no lateral branch development, and 21 (53%) had a mean branch number of less than one per tree. Only two genotypes had a mean branch number greater than one per tree. The pruning of axillary shoots on young papaya plants apparently has no effect on flowering, fruiting or disease control. Most papaya genotypes produce few or no lateral branches when left unpruned. Any lateral branches that are produced can be removed at the time of the first harvest.

scholarly journals Producing Double-stemmed Tomato Seedlings by Cutting Propagation, Pinching, and Plant Bioregulators Application

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 758C-758
Author(s):  
Ki-Yun Jung* ◽  
Bong-Hwa Kang ◽  
Yu-Jin Park ◽  
Jung-Myung Lee
Keyword(s):  
Axillary Shoot ◽  
Stem Cuttings ◽  
Subsequent Growth ◽  
Axillary Shoots ◽  
Tomato Seedlings ◽  
Cotyledonary Nodes ◽  
Whole Plant ◽  
Plug Seedling ◽  
Soil Mix ◽  
Lower Stem

Double-stemmed seedlings (DSS) will be favored by the growers because they can save the expense needed to purchase commercial seedlings. This is also true with grafted tomatoes since the price of grafted tomato seedlings is about 2 times higher than non-grafted ones. The plug seedling growers will also benefit from the increased demand for DSS if the production cost for DSS can be maintained at appropriate level. Two stem cuttings having two expanded leaves were taken from a seedling when the seedling had four expanded leaves and rooted in 32-cell trays filled with commercial soil mix. Lower stem cuttings having first and second leaves produced well-balanced DSS even without any plant bioregulator treatment whereas up upper stem cuttings having third and fourth leaves resulted in single-stem seedlings with very limited outgrowth of axillary shoot from the third node. DSS can be obtained from the decapitated seedling stump by outgrowth of axillary shoots from the cotyledonary nodes, but the quality and uniformity were inferior to other seedlings. Pinching off the tips of seedlings thus leaving three expanded leaves per seedling and application of plant bioregulators to the decapitated seedlings were also effective for producing DDS. Application of thidiazuron (TDZ) in lanolin paste to the second node was most effective even though whole plant spray with TDZ or BA was also partially effective. Subsequent growth characteristics of these seedlings will be further discussed.

scholarly journals Analysis of linseed (Linum usitatissiumum L.) plant branching as related to variability and interdependence of traits

2013 ◽  
Vol 57 (1-2) ◽  
pp. 187-205 ◽  
Author(s):  
Tadeusz Zając
Keyword(s):  
Morphological Traits ◽  
Branching Process ◽  
Weather Conditions ◽  
Planting Density ◽  
Young Plant ◽  
Plant Groups ◽  
Lateral Shoots ◽  
Weed Infestation ◽  
Biometric Measurements ◽  
Plant Shoots

Branching process of two linseed cultivars ('Hungarian Gold' and 'Opal') was analysed each year of vegetation between 1999 and 2002 characterised by different weather course. The estimation included also the extent and variability of selected morphological traits and structural traits. as well as correlation between them. On the basis of biometric measurements the hierarchy of plant shoots has been established within a plant, and four plant groups were distinguished: 1-. 2-, 3- and 4-shoot plants. It was demonstrated that the intensity of linseed branching depended mainly on young plant planting density and, to a certain extent also the weather conditions in April and May. In the years when the weather course favoured vegetation. between 23 and 40% plants per stand were branched. Beside increasing its productivity linseed branching may also inhibit a development of secondary weed infestation of the canopy. Similar plant groups with analogous shoot hierarchy formed in both linseed cultivars. Bio social position of shoot on a plant determined the extent of its traits. A dominance of the maiii shoot over lateral shoots was marked, especially concerning the number of seed vessels. Particularly big prevalence of the main shoot over lateral ones was visible in 3- and 4-9hoot plants. Lateral shoots had greater variability of morphological traits, especially concerning the number of seed vessels per shoot. Linear, exponential and power interdependencies between traits of linseed cultivars were also revealed.

scholarly journals Micropropagation of cloudberry (Rubus chamaemorus L.) by initiation of axillary shoots

2014 ◽  
Vol 70 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Barbara Thiem
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Botanical Garden ◽  
Axillary Shoot ◽  
Root Induction ◽  
Ms Medium ◽  
Axillary Shoots ◽  
Rubus Chamaemorus ◽  
Step Procedure

A method for micropropagation of the endangered <em>Rubus chamaemorus</em> L. (<em>Rosaceae</em>) from shoot tips was developed. Murashige and Skoog (MS) medium supplemented with BA and IBA in different concentrations was used for axillary shoot development. The most effective was MS medium containing 0.88 µM BA and 0.49 µM IBA with value of pH = 4.0. Cultures of microshoots (up to 12 shoots from a single explant) developed into regular shoots on the same medium or after transferring them onto MS media with 0.44 µM BA, 0.49 µM IBA and 434 µM SA. The rooting of initiated axillary shoots proved extremely difficult. A two-step procedure for root induction was adopted. Auxin- treated shoots were put to medium devoid of plant growth regulators. Rooted shoots were then transferred to pots and grown in the greenhouse until planted in the ground of the Botanical Garden.

Control of phyllotaxy in maize by the abphyl1 gene

Development ◽  
1999 ◽  
Vol 126 (2) ◽  
pp. 315-323 ◽  
Author(s):  
D. Jackson ◽  
S. Hake
Keyword(s):  
Apical Meristem ◽  
General Structure ◽  
Homeobox Gene ◽  
The Other ◽  
Shoot Meristem ◽  
Regular Pattern ◽  
Expression Domain ◽  
Geometric Patterns ◽  
Maize Plants ◽  
Shoot Meristems

Organogenesis in plants occurs at the shoot apical meristem, a group of indeterminate stem cells that are organized during embryogenesis. Regulated initiation of leaves or flowers from the shoot meristem gives rise to the familiar geometric patterns observed throughout the plant kingdom. The mechanism by which these patterns, termed phyllotaxies, are generated, remains unclear. Maize plants initiate leaves singly, alternating from one side to the other in a regular pattern. Here we describe a recessive maize mutant, abphyl1, that initiates leaves in opposite pairs, in a pattern termed decussate phyllotaxy. The decussate shoot meristems are larger than normal throughout development, though the general structure and organization of the meristem is not altered. abph1 mutants are first distinguished during embryogenesis, prior to true leaf initiation, by a larger shoot meristem and coincident larger expression domain of the homeobox gene knotted1. Therefore, the abph1 gene regulates morphogenesis in the embryo, and plays a role in determining the phyllotaxy of the shoot.

Micropropagation of Adult Red Maple and Sugar Maple

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 477e-478 ◽  
Author(s):  
David A. Connolly ◽  
John E. Preece ◽  
J.W. Van Sambeek
Keyword(s):  
Sugar Maple ◽  
Woody Plant ◽  
Acer Rubrum ◽  
Shoot Proliferation ◽  
Axillary Shoot ◽  
Red Maple ◽  
Axillary Shoots ◽  
Axillary Shoot Proliferation ◽  
Woody Plant Medium ◽  
The Media

Micropropagation studies were conducted to determine the best methods to achieve axillary shoot proliferation for adult Acer rubrum (red maple) and A. saccharium (sugar maple). The first experiment was conducted to compare the effects of 0.001, 0.01, 0.1 μM, 1 μM, and 10 μM thidiazuron (TDZ) using Driver-Kuniyuki-Walnut medium (DKW). The second experiment was conducted to examine the effects of DKW, Woody Plant Medium (WPM) and Long and Preece (LP) media in factorial combination with 0.01 and 0.1 μM TDZ. The third experiment was conducted to study the transfer timing (14 or 28 days) and the media solidification (agar-solidified or stationary liquid) on sugar maple. Both red maple and sugar maple explants on DKW with 0.1 μM TDZ produced the most and longest axillary shoots; however, sugar maple produced fewer axillary shoots than red maple. Red maple explants produced the most callus on DKW with 10 μM TDZ and the least on DKW with 0.001 μM TDZ. Sugar maple explants produced more shoots when explants were placed horizontally and transferred every 14 days than when placed vertically or transferred less frequently.

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