scholarly journals EjRAV1/2 Delay Flowering Through Transcriptional Repression of EjFTs and EjSOC1s in Loquat

2021 ◽  
Vol 12 ◽  
Author(s):  
Ze Peng ◽  
Man Wang ◽  
Ling Zhang ◽  
Yuanyuan Jiang ◽  
Chongbin Zhao ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Eriobotrya Japonica ◽  
Flower Initiation ◽  
Juvenile Period ◽  
Juvenile Phase ◽  
Reproductive Phase ◽  
Seasonal Flowering ◽  
Adult Tree ◽  
Lateral Branches ◽  
Shed Light

Most species in Rosaceae usually need to undergo several years of juvenile phase before the initiation of flowering. After 4–6 years’ juvenile phase, cultivated loquat (Eriobotrya japonica), a species in Rosaceae, enters the reproductive phase, blooms in the autumn and sets fruits during the winter. However, the mechanisms of the transition from a seedling to an adult tree remain obscure in loquat. The regulation networks controlling seasonal flowering are also largely unknown. Here, we report two RELATED TO ABI3 AND VP1 (RAV) homologs controlling juvenility and seasonal flowering in loquat. The expressions of EjRAV1/2 were relatively high during the juvenile or vegetative phase and low at the adult or reproductive phase. Overexpression of the two EjRAVs in Arabidopsis prolonged (about threefold) the juvenile period by repressing the expressions of flowering activator genes. Additionally, the transformed plants produced more lateral branches than the wild type plants. Molecular assays revealed that the nucleus localized EjRAVs could bind to the CAACA motif of the promoters of flower signal integrators, EjFT1/2, to repress their expression levels. These findings suggest that EjRAVs play critical roles in maintaining juvenility and repressing flower initiation in the early life cycle of loquat as well as in regulating seasonal flowering. Results from this study not only shed light on the control and maintenance of the juvenile phase, but also provided potential targets for manipulation of flowering time and accelerated breeding in loquat.

LEAFY expression and flower initiation in Arabidopsis

Development ◽  
1997 ◽  
Vol 124 (19) ◽  
pp. 3835-3844 ◽  
Author(s):  
M.A. Blazquez ◽  
L.N. Soowal ◽  
I. Lee ◽  
D. Weigel
Keyword(s):  
Life Cycle ◽  
Floral Induction ◽  
Shoot Meristem ◽  
Flower Initiation ◽  
Gradual Change ◽  
Vegetative Phase ◽  
Flower Meristem ◽  
Reproductive Phase ◽  
Plant Life Cycle ◽  
Short Days

During the initial vegetative phase, the Arabidopsis shoot meristem produces leaves with associated lateral shoots at its flanks, while the later reproductive phase is characterized by the formation of flowers. The LEAFY gene is an important element of the transition from the vegetative to the reproductive phase, as LEAFY is both necessary and sufficient for the initiation of individual flowers. We have analyzed in detail the expression of LEAFY during the plant life cycle, and found that LEAFY is extensively expressed during the vegetative phase. In long days, Arabidopsis plants flower soon after germination, and this is paralleled by rapid upregulation of LEAFY. In short days, Arabidopsis plants flower several weeks later than in long days, but LEAFY expression increases gradually before flowering commences. Application of the plant hormone gibberellin, which hastens flowering in short days, enhances the gradual change in LEAFY expression observed in short days. Changes in LEAFY expression before the transition to flowering suggest that the time point of this transition is at least partly controlled by the levels of LEAFY activity that are prevalent at a given time of the life cycle. This assumption is borne out by the finding that increasing the copy number of endogenous LEAFY reduces the number of leaves produced before the first flower is formed. Thus, LEAFY combines properties of flowering-time and flower-meristem-identity genes, indicating that LEAFY is a direct link between the global process of floral induction and the regional events associated with the initiation of individual flowers.

scholarly journals The Role of EjSVPs in Flower Initiation in Eriobotrya japonica

2019 ◽  
Vol 20 (23) ◽  
pp. 5933 ◽  
Author(s):  
Yuanyuan Jiang ◽  
Jiangrong Peng ◽  
Zhike Zhang ◽  
Shoukai Lin ◽  
Shunquan Lin ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Expression Patterns ◽  
Active Role ◽  
Eriobotrya Japonica ◽  
Flower Initiation ◽  
Mads Box ◽  
Promoter Regions ◽  
Expression Levels ◽  
Flowering Regulation ◽  
Responsive Element

Flowering plants have evolved different flowering habits to sustain long-term reproduction. Most woody trees experience dormancy and then bloom in the warm spring, but loquat blooms in the cold autumn and winter. To explore its mechanism of flowering regulation, we cloned two SHORT VEGETATIVE PHASE (SVP) homologous genes from ‘Jiefanzhong’ loquat (Eriobotrya japonica Lindl.), namely, EjSVP1 and EjSVP2. Sequence analysis revealed that the EjSVPs were typical MADS-box transcription factors and exhibited a close genetic relationship with other plant SVP/DORMANCY-ASSOCIATED MADS-BOX (DAM) proteins. The temporal and spatial expression patterns showed that EjSVP1 and EjSVP2 were mainly expressed in the shoot apical meristem (SAM) after the initiation of flowering; after reaching their highest level, they gradually decreased with the development of the flower until they could not be detected. EjSVP1 expression levels were relatively high in young tissues, and EjSVP2 expression levels were relatively high in young to mature transformed tissues. Interestingly, EjSVP2 showed relatively high expression levels in various flower tissues. We analyzed the EjSVP promoter regions and found that they did not contain the C-repeat/dehydration-responsive element. Finally, we overexpressed the EjSVPs in wild-type Arabidopsis thaliana Col-0 and found no significant changes in the number of rosette leaves of Arabidopsis thaliana; however, overexpression of EjSVP2 affected the formation of Arabidopsis thaliana flower organs. In conclusion, EjSVPs were found to play an active role in the development of loquat flowering. These findings may provide a reference for exploring the regulation mechanisms of loquat flowering and the dormancy mechanisms of other plants.

scholarly journals Poplar FT2 Shortens the Juvenile Phase and Promotes Seasonal Flowering

2006 ◽  
Vol 18 (8) ◽  
pp. 1846-1861 ◽  
Author(s):  
Chuan-Yu Hsu ◽  
Yunxia Liu ◽  
Dawn S. Luthe ◽  
Cetin Yuceer
Keyword(s):  
Juvenile Phase ◽  
Seasonal Flowering

scholarly journals Effect of Spacing and Sucker Removal on Precocity of Hazelnut Seedlings

1992 ◽  
Vol 117 (3) ◽  
pp. 523-526 ◽  
Author(s):  
Shawn A. Mehlenbacher ◽  
David C. Smith
Keyword(s):  
Corylus Avellana ◽  
Early Initiation ◽  
Breeding Cycle ◽  
Juvenile Period ◽  
Number Of Clusters ◽  
Juvenile Phase ◽  
Wide Spacing ◽  
The Difference ◽  
New Cultivars ◽  
Selection Of

The effect of parentage, spacing, and sucker removal on precocity of hazelnut (Corylus avellana L.) seedlings was investigated. Wider spacing (1.2 vs. 0.6 m) within the row doubled the number of nuts per seedling in the 5th year but had no effect on nut count in the 3rd or 4th year, nor did it affect the percentage of seedlings bearing nuts in any of the three years. Differences among the four progenies were highly significant for number of clusters, number of nuts, and percentage of seedlings bearing nuts in all years and for number of years to first fruiting. The progeny `Barcelona' × OSU 55.097 had the most bearing seedlings in, the 3rd year but was outperformed by `Casina' × OSU 55.129 in the 4th and 5th years. Number of years to first fruiting varied from 4.3 for `Casina' × OSU 55.129 to 5.2 for `Tombul' × `Tonda di Giffoni'. Sucker removal increased both the percentage of seedlings bearing nuts and the number of nuts per seedlings, but the difference was not significant until the 5th year. Sucker removal reduced the length of the juvenile phase by 3 months. The use of precocious parents was more effective than sucker removal in shortening the juvenile period, while sucker removal and wide spacing within seedling rows increased the number of nuts produced by seedlings in the 5th year. Selection of seedlings for early initiation of bearing will shorten the breeding cycle, and the resulting new cultivars will be precocious when planted in commercial orchards.

scholarly journals Seasonal Flowering of Heliconia ×rauliniana

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 882C-882
Author(s):  
Richard A. Criley*
Keyword(s):  
Research Study ◽  
Time Frame ◽  
Flower Initiation ◽  
Flower Production ◽  
Short Day ◽  
Shoot Production ◽  
Seasonal Flowering ◽  
Shoot Emergence

As part of a research study on growth and flower production of 20 commercial heliconia cultivars, plants were established at the Waimanalo Research Farm (Oahu) of the Univ. of Hawaii in July 1999. This report focuses on Heliconia ×rauliniana. Five plants in 7.6 L pots were planted at spacings of 2.5 M in row, with between row spacings of 3 M. Beginning a month later, newly emerged shoots were tagged every four weeks. At flowering, the shoots were harvested and leaf counts made. The information derived from the data include time frame from shoot emergence to flower, rate of shoot production, percentage of shoots from each tag date that flowered and the periodicity of flowering in a two year period. The range of times from shoot emergence to harvest was 208 to 450 days. In the first 12 months following planting, the average cumulative new shoot production since planting was 77 shoots per plant, while more than 58 inflorescences per plant were produced from the tagged stems for a 75% productivity rating. H. X rauliniana evidenced periodic flowering behavior, with peak flowering in the April to June period, that suggested it is a short-day plant for flower initiation.

scholarly journals TEMPERATURE IS A KEY REGULATOR OF GROWTH AND FLOWERING IN PROTEA NERIIFOLIA AND PROTEA CYNAROIDES

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 649g-649
Author(s):  
Steven Dupee ◽  
Peter Goodwin
Keyword(s):  
Field Data ◽  
Floral Development ◽  
Important Determinant ◽  
Stem Diameter ◽  
Flower Initiation ◽  
Cool Temperature ◽  
Floral Initiation ◽  
Vegetative Phase ◽  
Reproductive Phase ◽  
Temperature Regimes

The strategy of this study was to determine the period of floral initiation for both species and then to determine the critical regulator(s) of flower initiation and floral development. Plants grown under different temperature regimes gave best shoot extension and flower initiation at temperatures with 10°C night and 15 to 25°C day. Field data from four locations showed a correlation of time of flower initiation and temperatures over the same range. Temperature is an important determinant of the vegetative flush period of both species. The stem diameter of all shoots is a consequence of the vegetative flush growth and in turn is well correlated with flower initiation. Plants given day temperatures of 20°C or above remain in the vegetative phase. Flower abortions in Protea neriifolia and reversions from floral to vegetative shoots in Protea cynaroidesresult from high day temperatures. Daylength was not found to be critical for flower initiation. A cool temperature period acts as a control to change shoots from the vegetative to reproductive phase.

scholarly journals Adhesion dynamics in the neocortex determine the start of migration and the post-migratory orientation of neurons

2021 ◽  
Vol 7 (27) ◽  
pp. eabf1973
Author(s):  
Ekaterina Epifanova ◽  
Valentina Salina ◽  
Denis Lajkó ◽  
Kathrin Textoris-Taube ◽  
Thomas Naumann ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Transcriptional Repression ◽  
Integrin Signaling ◽  
Radial Migration ◽  
Parallel Orientation ◽  
Neocortical Development ◽  
Orientation Process ◽  
Neuropilin 1 ◽  
Neuronal Adhesion ◽  
Shed Light

The neocortex is stereotypically organized into layers of excitatory neurons arranged in a precise parallel orientation. Here we show that dynamic adhesion both preceding and following radial migration is essential for this organization. Neuronal adhesion is regulated by the Mowat-Wilson syndrome-associated transcription factor Zeb2 (Sip1/Zfhx1b) through direct repression of independent adhesion pathways controlled by Neuropilin-1 (Nrp1) and Cadherin-6 (Cdh6). We reveal that to initiate radial migration, neurons must first suppress adhesion to the extracellular matrix. Zeb2 regulates the multipolar stage by transcriptional repression of Nrp1 and thereby downstream inhibition of integrin signaling. Upon completion of migration, neurons undergo an orientation process that is independent of migration. The parallel organization of neurons within the neocortex is controlled by Cdh6 through atypical regulation of integrin signaling via its RGD motif. Our data shed light on the mechanisms that regulate initiation of radial migration and the postmigratory orientation of neurons during neocortical development.

scholarly journals The Role of EjSOC1s in Flower Initiation in Eriobotrya japonica

2019 ◽  
Vol 10 ◽  
Author(s):  
Yuanyuan Jiang ◽  
Jiangrong Peng ◽  
Yunmei Zhu ◽  
Wenbing Su ◽  
Ling Zhang ◽  
...  
Keyword(s):  
Eriobotrya Japonica ◽  
Flower Initiation

scholarly journals Breaking Dormancy in Red Raspberries for Greenhouse Production

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 515-519 ◽  
Author(s):  
Adam Dale ◽  
Angela Sample ◽  
Elizabeth King
Keyword(s):  
Northern Hemisphere ◽  
Rubus Idaeus ◽  
Flower Initiation ◽  
Red Raspberry ◽  
Chilling Temperature ◽  
Greenhouse Production ◽  
Breaking Dormancy ◽  
Lateral Branches ◽  
Time Required

Experiments were conducted to determine the chilling temperature and length of time required to break dormancy in red raspberry (Rubus idaeus L.). Five weeks of 7 °C with no light was sufficient to break dormancy in `Autumn Britten', `Nova', `Polana', and `Tulameen', while at least 8 weeks were needed for `Titan'. Comparisons with various chilling unit models allowed a model to be developed that could account for the observed chilling variation. In this model, each chilling hour was weighted as follows: below 5.6 °C = 1; 5.7 to 8.0 °C = 0.5; 8.1 to 11 °C = 0; 11.1 to 13 °C = -0.5; and >13 °C = -1. Plants of `Nova' and `Tulameen' chilled before flower initiation occurred, broke dormancy, and the resulting lateral branches remained vegetative. When the plants were fruited in the greenhouse, we were able to produce a second crop on the fruiting canes when the lateral branches that had fruited were removed. These experiments show that raspberries can be manipulated so that plants chilled in mid-September in the Northern Hemisphere can be induced to fruit by the beginning of January.

Sign in / Sign up

Export Citation Format

Share Document