Expression of a FLOWERING LOCUS T homologue is temporally associated with annual flower bud initiation in Eucalyptus globulus subsp. globulus (Myrtaceae)

2011 ◽  
Vol 59 (8) ◽  
pp. 756 ◽  
Author(s):  
Rebecca C. Jones ◽  
Valérie F. G. Hecht ◽  
Brad M. Potts ◽  
René E. Vaillancourt ◽  
James L. Weller
Keyword(s):  
Eucalyptus Globulus ◽  
Expression Patterns ◽  
Flower Initiation ◽  
Flowering Locus T ◽  
Flower Bud ◽  
Reproductive Growth ◽  
Environmental Signals ◽  
Flowering Genes ◽  
Flowering Locus ◽  
Bud Initiation

The transition to flowering in plants is the result of the balance of endogenous processes and environmental signals that act through a complex genetic pathway that has been studied extensively in annual plants such as Arabidopsis. Perennial trees are characterised by a juvenile non-flowering phase lasting several years followed by an adult phase in which there is repeated cycling between vegetative and reproductive growth. The genetic control of flowering time is potentially more complex in perennials than in annuals and is less understood. Here, we examine the control of flowering in Eucalyptus globulus subsp. globulus, an important forestry species in temperate parts of the world. The E. globulus subsp. globulus homologues of two important flowering genes FLOWERING LOCUS T (FT) and LEAFY (LFY) were isolated and quantitative RT-PCR was used to measure their expression over a 2-year period. The expression of the homologue of FT in E. globulus subsp. globulus leaves was associated with the annual transition from vegetative to reproductive growth (i.e. flower bud initiation). Expression of the LFY homologue was associated with early flower bud development. In a comparison of FT and LFY expression patterns in two clones each of an early and late anthesis genotype, no association between the expression of these genes and the timing of anthesis was shown. Taken together, this indicates that FT and LFY could form part of the flower initiation pathway in Eucalyptus but do not regulate the observed differences in anthesis time.

scholarly journals Role of PIF4 and FLC in controlling flowering time under daily variable temperature profile

2020 ◽  
Author(s):  
Jutapak Jenkitkonchai ◽  
Poppy Marriott ◽  
Weibing Yang ◽  
Napaporn Sriden ◽  
Jae-Hoon Jung ◽  
...  
Keyword(s):  
Flowering Time ◽  
Molecular Mechanisms ◽  
Transcriptional Regulatory Network ◽  
Variable Temperature ◽  
Loss Of Function ◽  
Environmental Signals ◽  
Regulatory Interactions ◽  
Flowering Genes ◽  
Gene Regulatory ◽  
Flowering Locus

ABSTRACTInitiation of flowering is a crucial developmental event that requires both internal and environmental signals to determine when floral transition should occur to maximize reproductive success. Ambient temperature is one of the key environmental signals that highly influence flowering time, not only seasonally but also in the context of drastic temperature fluctuation due to global warming. Molecular mechanisms of how high or low constant temperatures affect the flowering time have been largely characterized in the model plant Arabidopsis thaliana; however, the effect of natural daily variable temperature outside laboratories is only partly explored. Several groups of flowering genes have been shown to play important roles in temperature responses, including two temperature-responsive transcription factors (TFs), namely PHYTOCHROME INTERACTING FACTOR 4 (PIF4) and FLOWERING LOCUS C (FLC), that act antagonistically to regulate flowering time by activating or repressing floral integrator FLOWERING LOCUS T (FT). In this study, we have demonstrated that the daily variable temperature (VAR) causes early flowering in both natural accessions Col-0, C24 and their late flowering hybrid C24xCol, which carries both functional floral repressor FLC and its activator FRIGIDA (FRI), as compared to a constant temperature (CON). The loss-of-function mutation of PIF4 exhibits later flowering in VAR, suggesting that PIF4 at least in part, contributes to acceleration of flowering in response to the daily variable temperature. We find that VAR increases PIF4 transcription at the end of the day when temperature peaks at 32 °C. The FT transcription is also elevated in VAR, as compared to CON, in agreement with earlier flowering observed in VAR. In addition, VAR causes a decrease in FLC transcription in 4-week-old plants, and we further show that overexpression of PIF4 can reduce FLC transcription, suggesting that PIF4 might also regulate FT indirectly through the repression of FLC. To further conceptualize an overall model of gene regulatory mechanisms involving PIF4 and FLC in controlling flowering in response to temperature changes, we construct a co-expression – transcriptional regulatory network by combining publicly available transcriptomic data and gene regulatory interactions of our flowering genes of interest and their partners. The network model reveals the conserved and tissue-specific regulatory functions of 62 flowering-time-relating genes, namely PIF4, PIF5, FLC, ELF3 and their immediate neighboring genes, which can be useful for confirming and predicting the functions and regulatory interactions between the key flowering genes.

scholarly journals 295 The Effect of Cultivar, GA4+7, and Number of Fruit per Spur on Flower Initiation in Apple

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 493C-493
Author(s):  
Emily Hoover ◽  
S. McArtney ◽  
S. Tustin ◽  
M. White ◽  
P. Hirst
Keyword(s):  
Flower Initiation ◽  
Leaf Fall ◽  
Full Bloom ◽  
Flower Bud ◽  
Biennial Bearing ◽  
Appendage Formation ◽  
Commercial Crop ◽  
Bud Initiation ◽  
Number Of Seeds

Experiments were initiated to document the effect of cultivar, GA4+7, and number of fruit/spur on appendage number and flower bud initiation in apple. `Pacific Rose' is strongly biennial, `Braeburn' and `Fuji' are moderately biennial, and `Royal Gala' is not biennial. In the cultivar study, buds were sampled every 18 days starting at 50 days after full bloom and continuing through until leaf fall to determine the rate of appendage formation and appendage number in relation to doming. Because of the tendency for `Pacific Rose' to exhibit biennial bearing, the rate of appendage formation and the timing of doming were compared on nonfruiting trees, trees carrying a commercial crop, and trees sprayed with 300 PPM GA4+7 applied 14 days after full bloom. Number of appendages for the treatments were similar up to 100 days after full bloom. Presence of fruit on a spur has been demonstrated to inhibit flowering of apple. Spurs of `Pacific Rose', `Splendor', and `Royal Gala' were labeled with zero, one, two, and three fruit per spur and sampled three times during the season. As buds were harvested to count appendage number, the number of fruit per spur and the number of total seeds per spur were recorded. Correlation between number of seeds per spur and rate of appendage formation were done.

scholarly journals Isolation and Functional Analysis of Flowering Locus T in Tree Peonies (PsFT)

2015 ◽  
Vol 140 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Hua Zhou ◽  
Fang-Yun Cheng ◽  
Jing Wu ◽  
Chaoying He
Keyword(s):  
Flowering Time ◽  
Woody Plants ◽  
Potential Role ◽  
Expression Patterns ◽  
Wild Type ◽  
Coding Region ◽  
Flowering Locus T ◽  
Wide Range ◽  
Flowering Locus ◽  
Ornamental Shrub

Arabidopsis thaliana Flowering locus T (FT) homologs have been shown to be sufficient to trigger flowering and to regulate flowering time in a wide range of plants. However, such a homologue for the perennial ornamental shrub tree peony has not yet been characterized. In this study, we isolated PsFT, which is a closely related FT homolog from reblooming [Paeonia ×lemoinei ‘High Noon’ (HN)] and nonreblooming [P. ×suffruticosa ‘Luo Yang Hong’ (LYH)] cultivars of tree peonies, and identified its potential role in the regulation of flowering time. The PsFT alleles from the two cultivars encode the same protein, which indicates that the polymorphisms observed in the coding region do not contribute to the distinct flowering phenotypes of HN and LYH. Comparative analyses of the PsFT expression patterns in HN and LYH indicated that PsFT might be associated with reblooming. Transgenic A. thaliana plants ectopically expressing PsFT exhibited a phenotype that included significantly early flowering compared with the wild-type (WT) plants. Taken together, our data provide valuable clues for shortening the juvenile periods and extending the flowering periods of perennial woody plants, such as tree peonies.

Two FLOWERING LOCUS T (FT) homologs in Chenopodium rubrum differ in expression patterns

Planta ◽  
2008 ◽  
Vol 228 (6) ◽  
pp. 929-940 ◽  
Author(s):  
David Cháb ◽  
Jan Kolář ◽  
Matthew S. Olson ◽  
Helena Štorchová
Keyword(s):  
Expression Patterns ◽  
Chenopodium Rubrum ◽  
Flowering Locus T ◽  
Flowering Locus

Blossom Thinning in Pome and Stone Fruit

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 553b-553
Author(s):  
Esmaeil Fallahi
Keyword(s):  
Fruit Size ◽  
Naphthalene Acetic Acid ◽  
Full Bloom ◽  
Flower Bud ◽  
Hydrogen Cyanamide ◽  
Ammonium Thiosulfate ◽  
The Past ◽  
Apple Cultivars ◽  
Ortho Cresol ◽  
Bud Initiation

Early thinning of apples is important because of its impact on fruit size and next season's flower bud initiation. In the past, apple cultivars were often sprayed with the blossom thinner sodium dinitro-ortho-cresol(Elgetol) during full bloom, followed by a post-bloom application of a fruit thinner such as carbaryl with or without naphthalene acetic acid (NAA). Elgetol was removed from the market in 1989 because of the high cost of re-registration. Full-bloom sprays of sulfcarbamide (Wilthin), pelargonic acid (Thinex), and endothalic acid (Endothal), ammonium thiosulfate (ATS) or petal fall spray of carbaryl (Sevin XLR Plus) were developed as replacements for Elgetol. Hydrogen cyanamide (HC) and other chemicals have been used to eliminate or to reduce chilling requirements of peaches grown under the warm desert conditions. HC applied at “pink bloom” stage was observed to reduce the number of open blooms in `Florda Prince' peach; therefore, it was first used for blossom thinning in this cultivar in Arizona. Later, HC was also found to be an effective blossom thinner for plums in Idaho. HC has recently been found to effectively thin apple and peach blossoms. Armothin has also been an effective blossom thinner for peach in California.

scholarly journals A novel deletion in FLOWERING LOCUS T modulates flowering time in winter oilseed rape

2021 ◽  
Author(s):  
Paul Vollrath ◽  
Harmeet S. Chawla ◽  
Sarah V. Schiessl ◽  
Iulian Gabur ◽  
HueyTyng Lee ◽  
...  
Keyword(s):  
Association Mapping ◽  
Flowering Time ◽  
Oilseed Rape ◽  
Major Effect ◽  
Structural Variants ◽  
Winter Oilseed Rape ◽  
Flowering Locus T ◽  
Winter Type ◽  
Long Read ◽  
Flowering Locus

Abstract Key message A novel structural variant was discovered in the FLOWERING LOCUS T orthologue BnaFT.A02 by long-read sequencing. Nested association mapping in an elite winter oilseed rape population revealed that this 288 bp deletion associates with early flowering, putatively by modification of binding-sites for important flowering regulation genes. Abstract Perfect timing of flowering is crucial for optimal pollination and high seed yield. Extensive previous studies of flowering behavior in Brassica napus (canola, rapeseed) identified mutations in key flowering regulators which differentiate winter, semi-winter and spring ecotypes. However, because these are generally fixed in locally adapted genotypes, they have only limited relevance for fine adjustment of flowering time in elite cultivar gene pools. In crosses between ecotypes, the ecotype-specific major-effect mutations mask minor-effect loci of interest for breeding. Here, we investigated flowering time in a multiparental mapping population derived from seven elite winter oilseed rape cultivars which are fixed for major-effect mutations separating winter-type rapeseed from other ecotypes. Association mapping revealed eight genomic regions on chromosomes A02, C02 and C03 associating with fine modulation of flowering time. Long-read genomic resequencing of the seven parental lines identified seven structural variants coinciding with candidate genes for flowering time within chromosome regions associated with flowering time. Segregation patterns for these variants in the elite multiparental population and a diversity set of winter types using locus-specific assays revealed significant associations with flowering time for three deletions on chromosome A02. One of these was a previously undescribed 288 bp deletion within the second intron of FLOWERING LOCUS T on chromosome A02, emphasizing the advantage of long-read sequencing for detection of structural variants in this size range. Detailed analysis revealed the impact of this specific deletion on flowering-time modulation under extreme environments and varying day lengths in elite, winter-type oilseed rape.

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