scholarly journals Massive haplotypes underlie ecotypic differentiation in sunflowers

2019 ◽  
Author(s):  
Marco Todesco ◽  
Gregory L. Owens ◽  
Natalia Bercovich ◽  
Jean-Sébastien Légaré ◽  
Shaghayegh Soudi ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Flowering Time ◽  
Seed Size ◽  
Structural Variation ◽  
Structural Variants ◽  
Flowering Locus T ◽  
Ecotypic Differentiation ◽  
Haplotype Blocks ◽  
Flowering Locus

Species often include multiple ecotypes that are adapted to different environments. But how do ecotypes arise, and how are their distinctive combinations of adaptive alleles maintained despite hybridization with non-adapted populations? Re-sequencing of 1506 wild sunflowers from three species identified 37 large (1-100 Mbp), non-recombining haplotype blocks associated with numerous ecologically relevant traits, and soil and climate characteristics. Limited recombination in these regions keeps adaptive alleles together, and we find that they differentiate several sunflower ecotypes; for example, they control a 77 day difference in flowering between ecotypes of silverleaf sunflower (likely through deletion of a FLOWERING LOCUS T homolog), and are associated with seed size, flowering time and soil fertility in dune-adapted sunflowers. These haplotypes are highly divergent, associated with polymorphic structural variants, and often appear to represent introgressions from other, possibly extinct, congeners. This work highlights a pervasive role of structural variation in maintaining complex ecotypic adaptation.

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.

scholarly journals FLOWERING LOCUS T4 (HvFT4) delays flowering and decreases floret fertility in barley

2020 ◽  
Author(s):  
Rebecca Pieper ◽  
Filipa Tomé ◽  
Maria von Korff
Keyword(s):  
Flowering Time ◽  
Reproductive Development ◽  
Negative Regulator ◽  
Flowering Locus T ◽  
Time Control ◽  
Photoperiodic Regulation ◽  
Flowering Locus ◽  
Delayed Flowering ◽  
Flowering Time Control

AbstractFLOWERING LOCUS T-like genes (FT-like) control the photoperiodic regulation of flowering in many angiosperm plants. The family of FT-like genes is characterised by extensive gene duplication and subsequent diversification of FT functions which occurred independently in modern angiosperm lineages. In barley, there are 12 known FT-like genes (HvFT) but the function of most of them remains uncharacterised. This study aimed to characterise the role of HvFT4 in flowering time control and development in barley. The overexpression of HvFT4 in the spring cultivar Golden Promise delayed flowering time under long-day conditions. Microscopic dissection of the shoot apical meristem (SAM) revealed that overexpression of HvFT4 specifically delayed spikelet initiation and reduced the number of spikelet primordia and grains per spike. Furthermore, ectopic overexpression of HvFT4 was associated with floret abortion and with the downregulation of the barley MADS-box genes VRN-H1, HvBM3 and HvBM8 which promote floral development. This suggests that HvFT4 functions as a repressor of reproductive development in barley. Unraveling the genetic basis of FT-like genes can contribute to the identification of novel breeding targets to modify reproductive development and thereby spike morphology and grain yield.HighlightWe identify the FLOWERING LOCUS T (FT)-like gene HvFT4 as a negative regulator of reproductive development, spikelet initiation, floret fertility and grain number in barley.

scholarly journals Isolation and Functional Characterization of MsFTa, a FLOWERING LOCUS T Homolog from Alfalfa (Medicago sativa)

2019 ◽  
Vol 20 (8) ◽  
pp. 1968 ◽  
Author(s):  
Junmei Kang ◽  
Tiejun Zhang ◽  
Tao Guo ◽  
Wang Ding ◽  
Ruicai Long ◽  
...  
Keyword(s):  
Flowering Time ◽  
Functional Characterization ◽  
Flowering Locus T ◽  
Over Expression ◽  
Long Day ◽  
Gfp Fusion Protein ◽  
Intron Structure ◽  
Flowering Locus ◽  
Flowering Regulation

The production of hay and seeds of alfalfa, an important legume forage for the diary industry worldwide, is highly related to flowering time, which has been widely reported to be integrated by FLOWERING LOCUS T (FT). However, the function of FT(s) in alfalfa is largely unknown. Here, we identified MsFTa, an FT ortholog in alfalfa, and characterized its role in flowering regulation. MsFTa shares the conserved exon/intron structure of FTs, and MsFTa is 98% identical to MtFTa1 in Medicago trucatula. MsFTa was diurnally regulated with a peak before the dark period, and was preferentially expressed in leaves and floral buds. Transient expression of MsFTa-GFP fusion protein demonstrated its localization in the nucleus and cytoplasm. When ectopically expressed, MsFTa rescued the late-flowering phenotype of ft mutants from Arabidopsis and M. trucatula. MsFTa over-expression plants of both Arabidopsis and M. truncatula flowered significantly earlier than the non-transgenic controls under long day conditions, indicating that exogenous MsFTa strongly accelerated flowering. Hence, MsFTa functions positively in flowering promotion, suggesting that MsFTa may encode a florigen that acts as a key regulator in the flowering pathway. This study provides an effective candidate gene for optimizing alfalfa flowering time by genetically manipulating the expression of MsFTa.

scholarly journals The structural variation landscape in 492 Atlantic salmon genomes

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Alicia C. Bertolotti ◽  
Ryan M. Layer ◽  
Manu Kumar Gundappa ◽  
Michael D. Gallagher ◽  
Ege Pehlivanoglu ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Neurological Disorders ◽  
Genetic Architecture ◽  
Structural Variation ◽  
Structural Variants ◽  
Model Species ◽  
Farmed Fish ◽  
Functional Features ◽  
Polygenic Selection

Abstract Structural variants (SVs) are a major source of genetic and phenotypic variation, but remain challenging to accurately type and are hence poorly characterized in most species. We present an approach for reliable SV discovery in non-model species using whole genome sequencing and report 15,483 high-confidence SVs in 492 Atlantic salmon (Salmo salar L.) sampled from a broad phylogeographic distribution. These SVs recover population genetic structure with high resolution, include an active DNA transposon, widely affect functional features, and overlap more duplicated genes retained from an ancestral salmonid autotetraploidization event than expected. Changes in SV allele frequency between wild and farmed fish indicate polygenic selection on behavioural traits during domestication, targeting brain-expressed synaptic networks linked to neurological disorders in humans. This study offers novel insights into the role of SVs in genome evolution and the genetic architecture of domestication traits, along with resources supporting reliable SV discovery in non-model species.

scholarly journals Dehydroabietinal promotes flowering time and plant defense in Arabidopsis via the autonomous pathway genes FLOWERING LOCUS D, FVE, and RELATIVE OF EARLY FLOWERING 6

2020 ◽  
Vol 71 (16) ◽  
pp. 4903-4913 ◽  
Author(s):  
Zulkarnain Chowdhury ◽  
Devasantosh Mohanty ◽  
Mrunmay K Giri ◽  
Barney J Venables ◽  
Ratnesh Chaturvedi ◽  
...  
Keyword(s):  
Flowering Time ◽  
Systemic Acquired Resistance ◽  
Defense Mechanism ◽  
Acquired Resistance ◽  
Early Flowering ◽  
Negative Regulator ◽  
Flowering Locus T ◽  
Autonomous Pathway ◽  
Abietane Diterpenoids ◽  
Flowering Locus

Abstract Abietane diterpenoids are tricyclic diterpenes whose biological functions in angiosperms are largely unknown. Here, we show that dehydroabietinal (DA) fosters transition from the vegetative phase to reproductive development in Arabidopsis thaliana by promoting flowering time. DA’s promotion of flowering time was mediated through up-regulation of the autonomous pathway genes FLOWERING LOCUS D (FLD), RELATIVE OF EARLY FLOWERING 6 (REF6), and FVE, which repress expression of FLOWERING LOCUS C (FLC), a negative regulator of the key floral integrator FLOWERING LOCUS T (FT). Our results further indicate that FLD, REF6, and FVE are also required for systemic acquired resistance (SAR), an inducible defense mechanism that is also activated by DA. However, unlike flowering time, FT was not required for DA-induced SAR. Conversely, salicylic acid, which is essential for the manifestation of SAR, was not required for the DA-promoted flowering time. Thus, although the autonomous pathway genes FLD, REF6, and FVE are involved in SAR and flowering time, these biological processes are not interdependent. We suggest that SAR and flowering time signaling pathways bifurcate at a step downstream of FLD, REF6, and FVE, with an FLC-dependent arm controlling flowering time, and an FLC-independent pathway controlling SAR.

scholarly journals GWAS hints at pleiotropic roles for FLOWERING LOCUS T in flowering time and yield-related traits in canola

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Harsh Raman ◽  
Rosy Raman ◽  
Yu Qiu ◽  
Avilash Singh Yadav ◽  
Sridevi Sureshkumar ◽  
...  
Keyword(s):  
Flowering Time ◽  
Flowering Locus T ◽  
Flowering Locus

scholarly journals Natural Variation of the RICE FLOWERING LOCUS T 1 Contributes to Flowering Time Divergence in Rice

PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e75959 ◽  
Author(s):  
Eri Ogiso-Tanaka ◽  
Kazuki Matsubara ◽  
Shin-ichi Yamamoto ◽  
Yasunori Nonoue ◽  
Jianzhong Wu ◽  
...  
Keyword(s):  
Flowering Time ◽  
Natural Variation ◽  
Flowering Locus T ◽  
Flowering Locus

scholarly journals BBX19 Interacts with CONSTANS to Repress FLOWERING LOCUS T Transcription, Defining a Flowering Time Checkpoint in Arabidopsis

2014 ◽  
Vol 26 (9) ◽  
pp. 3589-3602 ◽  
Author(s):  
C.-Q. Wang ◽  
C. Guthrie ◽  
M. K. Sarmast ◽  
K. Dehesh
Keyword(s):  
Flowering Time ◽  
Flowering Locus T ◽  
Flowering Locus

scholarly journals Role of FRIGIDA and FLOWERING LOCUS C in Determining Variation in Flowering Time of Arabidopsis

2005 ◽  
Vol 138 (2) ◽  
pp. 1163-1173 ◽  
Author(s):  
Chikako Shindo ◽  
Maria Jose Aranzana ◽  
Clare Lister ◽  
Catherine Baxter ◽  
Colin Nicholls ◽  
...  
Keyword(s):  
Flowering Time ◽  
Flowering Locus C ◽  
Flowering Locus
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