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1.
Alfonso Cuesta-Marcos Ernesto Igartua Francisco J. Ciudad Primitiva Codesal Joanne R. Russell José L. Molina-Cano Marian Moralejo Peter Szűcs María Pilar Gracia José M. Lasa Ana M. Casas 《Molecular breeding : new strategies in plant improvement》2008,21(4):455-471
Heading date is a key trait for the adaptation of barley to Mediterranean environments. We studied the genetic control of
flowering time under Northern Spanish (Mediterranean) conditions using a new population derived from the spring/winter cross
Beka/Mogador. A set of 120 doubled haploid lines was evaluated in the field, and under controlled temperature and photoperiod
conditions. Genotyping was carried out with 215 markers (RFLP, STS, RAPD, AFLP, SSR), including markers for vernalization
candidate genes, HvBM5 (Vrn-H1), HvZCCT (Vrn-H2), and HvT SNP22 (Ppd-H1). Four major QTL, and the interactions between them, accounted for most of the variation in both field (71–92%) and greenhouse
trials (55–86%). These were coincident with the location of the major genes for response to vernalization and short photoperiod
(Ppd-H2 on chromosome 1H). A major QTL, near the centromere of chromosome 2H was the most important under autumn sowing conditions.
Although it is detected under all conditions, its action seems not independent from environmental cues. An epistatic interaction
involving the two vernalization genes was detected when the plants were grown without vernalization and under long photoperiod.
The simultaneous presence of the winter Mogador allele at the two loci produced a marked delay in heading date, beyond a mere
additive effect. This interaction, combined with the effect of the gene responsive to short photoperiod, Ppd-H2, was found responsible of the phenomenon known as short-day vernalization, present in some of the lines of the population.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Molecular mapping of the photoperiod response gene ea7 in barley 总被引:1,自引:0,他引:1
S. Stracke A. Börner 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):797-800
The gene ea
7
determining photoperiod insensitivity under short day length was mapped on the short arm of chromosome 6H near the centromere.
The gene was linked to the two flanking markers Xmwg2264 and Xmwg916 by 6.7 and 13.0 cM, respectively. Compared to Ppd-H1 (chromosome 2H) and Ppd-H2 (chromosome 1H), ea
7
determines the strongest effect on flowering time with 55 and 18 days difference compared to photoperiod sensitive genotypes
grown under short and long photoperiods, respectively. Allelic and homoeologous relationships to major genes and quantitative
trait loci controlling flowering time in barley and wheat are discussed.
Received: 10 March 1998 / Accepted: 7 April 1998 相似文献
3.
Alfonso Cuesta-Marcos Ana M. Casas Samia Yahiaoui M. Pilar Gracia José M. Lasa Ernesto Igartua 《Molecular breeding : new strategies in plant improvement》2008,21(3):383-399
The purpose of the present work is to validate the effect of the main QTL determining heading date in a set of 281 doubled
haploid lines of barley, derived from 17 small interconnected populations, whose parents are cultivars commonly used in the
Spanish barley breeding program. We used 72 molecular markers distributed across the seven chromosomes, particularly in regions
known to contain flowering time genes or QTL. A combined linkage map over the 17 populations was constructed. The lines were
evaluated in four field trials: two autumn sowings and two winter sowings, and in two treatments at a greenhouse trial, under
controlled conditions of photoperiod and temperature. We have found that it is possible to carry out QTL detection in a complex
germplasm set, representative of the materials used in an active breeding programme. In most cases two alleles per QTL were
detected, though polymorphism of flanking markers was notably higher. The results revealed that there is a set of QTL that
accounts for an important percentage of the phenotypic variation, suitable for marker assisted selection. Also, the role of
the regions carrying the photoperiod response genes Ppd-H1 and Ppd-H2, the vernalization response genes Vrn-H1 and Vrn-H2, and the earliness per se locus Eam6, of which allele-specific or closely linked markers were available, was confirmed. These results support the use of this
kind of approach for the validation of QTL found in single cross population studies, or to survey allelic diversity in plant
breeding sets of materials.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
4.
Epigenetic regulation of flowering 总被引:3,自引:0,他引:3
The acceleration of flowering by prolonged low temperature treatment (vernalization) has unique properties including the floral transition occurring at a time separate from the vernalization treatment. This implies the vernalization condition is inherited through mitotic divisions, but this vernalized state is not inherited from one generation to the next. FLC, the key gene mediating this response in the Arabidopsis is repressed by histone modifications involving the VRN2 protein complex. Other protein complexes participate in activating the gene. While many plant species depend on vernalization for optimising flowering time, the genes involved differ between dicot and monocot plants in both Arabidopsis and cereals, vernalization regulates photoperiod control of flowering by preventing the induction of the floral promoter FT by long days in autumn but allowing induction of FT in spring and hence flowering occurs at an optimal time in the annual life cycle. 相似文献
5.
I. Karsai K. Mészáros P. M. Hayes Z. Bedő 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(5):612-618
Heading-date in cereals is the final result of a number of interacting characters that include vernalization requirement,
photoperiod sensitivity, and earliness per se. Progress in developing adapted varieties may be achieved by determining the chromosomal locations of genes controlling these
characters. Nineteen doubled-haploid (DH) lines from the Dicktoo×Morex mapping population were phenotyped in controlled- environment photoperiod experiments to determine the role of two previously
detected QTLs on the developmental patterns of barley. The QTLs are hypothesised to represent the effects of the Ppd and Sh2 loci on chromosomes 2 (2H) and 7 (5H), respectively. Alleles at the Ppd locus were found to be vary in response to photoperiod duration. Vernalization had some effect on alleles at both loci. The
presence of early and late- flowering transgressive segregants in this mapping population can be explained by interactions
between the Ppd and Sh2 loci. The Ppd and Sh2 loci are hypothesised to be homoeologous with the Ppd and Vrn1 loci of wheat.
Received: 1 August 1996 / Accepted: 15 November 1996 相似文献
6.
The quantitative response of wheat vernalization to environmental variables indicates that vernalization is not a response to cold temperature 总被引:1,自引:0,他引:1
Allard V Veisz O Kõszegi B Rousset M Le Gouis J Martre P 《Journal of experimental botany》2012,63(2):847-857
The initiation of flowering is a crucial trait that allows temperate plants to flower in the favourable conditions of spring. The timing of flowering initiation is governed by two main mechanisms: vernalization that defines a plant's requirement for a prolonged exposure to cold temperatures; and photoperiod sensitivity defining the need for long days to initiate floral transition. Genetic variability in both vernalization and photoperiod sensitivity largely explains the adaptability of cultivated crop plants such as bread wheat (Triticum aestivum L.) to a wide range of climatic conditions. The major genes controlling wheat vernalization (VRN1, VRN2, and VRN3) and photoperiod sensitivity (PPD1) have been identified, and knowledge of their interactions at the molecular level is growing. However, the quantitative effects of temperature and photoperiod on these genes remain poorly understood. Here it is shown that the distinction between the temperature effects on organ appearance rate and on vernalization sensu stricto is crucial for understanding the quantitative effects of the environmental signal on wheat flowering. By submitting near isogenic lines of wheat differing in their allelic composition at the VRN1 locus to various temperature and photoperiod treatments, it is shown that, at the whole-plant level, the vernalization process has a positive response to temperature with complex interactions with photoperiod. In addition, the phenotypic variation associated with the presence of different spring homoeoalleles of VRN1 is not induced by a residual vernalization requirement. The results demonstrate that a precise definition of vernalization is necessary to understand and model temperature and photoperiod effects on wheat flowering. It is suggested that this definition should be used as the basis for gene expression studies and assessment of functioning of the wheat flowering gene network, including an explicit account of the quantitative effect of environmental variables. 相似文献
7.
8.
Detection of QTLs for heading time and photoperiod response in wheat using a doubled-haploid population. 总被引:16,自引:0,他引:16
The genetic basis of heading time in wheat (Triticum aestivum L.) was investigated through the study of flowering under normal autumn sown field conditions as well as photoperiod responses under a controlled environment. Quantitative trait loci (QTLs) for these traits were mapped in a doubled-haploid (DH) population derived from a cross between the wheat cultivars 'Courtot' and 'Chinese Spring'. A molecular marker linkage map of this cross that was previously constructed based on 187 DH lines and 380 markers was used for QTL mapping. The genome was well covered (85%) except for chromosomes 1D and 4D, and a set of anchor loci regularly spaced over the genome (one marker each 15.5 cM) was chosen for marker regression analysis. The presence of a QTL was declared at a significance threshold of alpha = 0.005. The population was grown under field conditions in Clermont-Ferrand, France during two years (1994-1995), in Norwich, U.K. over one year (1998), and also under controlled environments in Norwich. For each trait, between 2 and 4 QTLs were identified with individual effects ranging between 6.3% and 44.4% of the total phenotypic variation. Two QTLs were detected that simultaneously affected heading time and photoperiod response. For heading time, these two QTLs were detected in more than one year. One QTL located on chromosome arm 2BS near the locus Xfbb121-2B, co-segregated with the gene Ppd-B1 known to be involved in photoperiod response. This chromosome region explained a large part of the variation (23.4-44.4% depending on the years or the traits). Another region located on chromosome arm 7BS between the loci Xfbb324-7B and Xfbb53-7B also had a strong effect (7.3-15.3%). This region may correspond to a QTL for earliness per se. 相似文献
9.
Szucs P Karsai I von Zitzewitz J Mészáros K Cooper LL Gu YQ Chen TH Hayes PM Skinner JS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(7):1277-1285
Winterhardiness has three primary components: photoperiod (day length) sensitivity, vernalization response, and low temperature
tolerance. Photoperiod and vernalization regulate the vegetative to reproductive phase transition, and photoperiod regulates
expression of key vernalization genes. Using two barley mapping populations, we mapped six individual photoperiod response
QTL and determined their positional relationship to the phytochrome and cryptochrome photoreceptor gene families and the vernalization
regulatory genes HvBM5A, ZCCT-H, and HvVRT-2. Of the six photoreceptors mapped in the current study (HvPhyA and HvPhyB to 4HS, HvPhyC to 5HL, HvCry1a and HvCry2 to 6HS, and HvCry1b to 2HL), only HvPhyC coincided with a photoperiod response QTL. We recently mapped the candidate genes for the 5HL VRN-H1 (HvBM5A) and 4HL VRN-H2 (ZCCT-H) loci, and in this study, we mapped HvVRT-2, the barley TaVRT-2 ortholog (a wheat flowering repressor regulated by vernalization and photoperiod) to 7HS. Each of these three vernalization
genes is located in chromosome regions determining small photoperiod response QTL effects. HvBM5A and HvPhyC are closely linked on 5HL and therefore are currently both positional candidates for the same photoperiod effect. The coincidence
of photoperiod-responsive vernalization genes with photoperiod QTL suggests vernalization genes should also be considered
candidates for photoperiod effects. 相似文献
10.
Holland B Portyanko A Hoffman L Lee M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,105(1):113-126
Oat genotypes vary for photoperiod and vernalization responses. Vernalization often promotes earlier flowering in fall-sown but not spring-sown cultivars. Longer photoperiods also promote earlier flowering, and the response to longer photoperiods tends to be greater in cultivars from higher latitudes. To investigate the genetic basis of photoperiod and vernalization responses in oat, we mapped QTLs for flowering time under four combinations of photoperiod and vernalization treatments in the Ogle 2 TAM O-301 mapping population in growth chambers. We also mapped QTLs for flowering time in early spring and late-spring field plantings to determine the genetic basis of response to early spring planting in oat. Three major flowering-time QTLs (on linkage groups OT8, OT31 and OT32) were detected in most conditions. QTLs with smaller effects on flowering were less-consistently observed among treatments. Both vernalization-sensitive and insensitive QTLs were discovered. Longer photoperiod or vernalization alone tended to decrease the effects of flowering-time QTLs. Applied together, longer photoperiod and vernalization interacted synergistically, often on the same genomic regions. Earlier spring planting conferred an attenuated vernalization treatment on seeds. The major flowering-time QTLs mapped in this study matched those mapped previously in the Kanota 2 Ogle oat mapping population. Between these two studies, we found a concordance of flowering-time QTLs, segregation distortion, and complex genetic linkages. These effects may all be related to chromosomal rearrangements in hexaploid oat. Comparative mapping between oat and other grasses will facilitate molecular analysis of vernalization response in oat. 相似文献
11.
Low-temperature tolerance and genetic potential in wheat (Triticum aestivum L.): response to photoperiod, vernalization, and plant development 总被引:12,自引:0,他引:12
It is frequently observed that winter habit types are more low-temperature (LT) tolerant than spring habit types. This raises the question of whether this is due to pleiotropic effects of the vernalization loci or to the linkage of LT-tolerance genes to these vernalization loci. Reciprocal near-isogenic lines (NILs) for alleles at the Vrn-A1 locus, Vrn-A1 and vrn-A1, determining spring and winter habit respectively, in two diverse genetic backgrounds of wheat (Triticum aestivum L.) were used to separate the effects of vernalization, photoperiod, and development on identical, or near identical, genetic backgrounds. The vrn-A1 allele in the winter lines allowed full expression of genotype dependent LT tolerance potential. The winter allele (vrn-A1) in a very cold tolerant genetic background resulted in 11°C, or a 2.4-fold, greater LT tolerance compared to the spring allele. Similarly, the delay in development caused by short-day (SD) versus long-day (LD) photoperiod in the identical spring habit NIL resulted in an 8.5°C or 2.1-fold, increase in LT tolerance. The duration of time in early developmental stages was shown to underlie full expression of genetic LT-tolerance potential. Therefore, pleiotropic effects of the vernalization loci can explain the association of LT tolerance and winter habit irrespective of either the proposed closely linked Fr-A1 or the more distant Fr-A2 LT-tolerance QTLs. Plant development progressively reduced LT-acclimation ability, particularly after the main shoot meristem had advanced to the double ridge reproductive growth stage. The Vrn-1 genes, or other members of the flowering induction pathway, are discussed as possible candidates for involvement in LT-tolerance repression. 相似文献
12.
Comparison of Flowering Time Genes in Brassica Rapa, B. Napus and Arabidopsis Thaliana 总被引:15,自引:0,他引:15
T. C. Osborn C. Kole IAP. Parkin A. G. Sharpe M. Kuiper D. J. Lydiate M. Trick 《Genetics》1997,146(3):1123-1129
The major difference between annual and biennial cultivars of oilseed Brassica napus and B. rapa is conferred by genes controlling vernalization-responsive flowering time. These genes were compared between the species by aligning the map positions of flowering time quantitative trait loci (QTLs) detected in a segregating population of each species. The results suggest that two major QTLs identified in B. rapa correspond to two major QTLs identified in B. napus. Since B. rapa is one of the hypothesized diploid parents of the amphidiploid B. napus, the vernalization requirement of B. napus probably originated from B. rapa. Brassica genes also were compared to flowering time genes in Arabidopsis thaliana by mapping RFLP loci with the same probes in both B. napus and Arabidopsis. The region containing one pair of Brassica QTLs was collinear with the top of chromosome 5 in A. thaliana where flowering time genes FLC, FY and CO are located. The region containing the second pair of QTLs showed fractured collinearity with several regions of the Arabidopsis genome, including the top of chromosome 4 where FRI is located. Thus, these Brassica genes may correspond to two genes (FLC and FRI) that regulate flowering time in the latest flowering ecotypes of Arabidopsis. 相似文献
13.
Control of flowering time is an adaptive trait of plants for different growth habitats. A vernalization requirement is a major genetic component determining wheat flowering time. Arabidopsis VERNALIZATION INSENSITIVE3 (VIN3) and VIN3-like 1 (VIL1) play critical roles in the vernalization pathway of flowering, and three wheat VIL homologs are upregulated by vernalization in einkorn wheat. To study the relationship between vernalization and wheat VIL homologs in Aegilops tauschii, the D-genome progenitor of common wheat, we isolated three cDNAs orthologous to the einkorn wheat VIL genes. The three Ae. tauschii VIL genes showed many single nucleotide polymorphisms including non-synonymous substitutions relative to the einkorn orthologs. In addition, high rates of non-synonymous and synonymous substitutions were revealed by intraspecific variation analysis of the AetVIL sequences, suggesting adaptive evolution at the AetVIL loci. Quantitative RT-PCR analysis was conducted to examine the time course of expression of the VIL genes during vernalization. Of the three AetVIL genes, AetVIL2 was upregulated after one week of low-temperature treatment, and its expression pattern was distinct for winter and spring habit accessions. These observations strongly suggest that AetVIL2 is associated with the vernalization-responsive pathway in Ae. tauschii. 相似文献
14.
Karsai I Szucs P Mészáros K Filichkina T Hayes PM Skinner JS Láng L Bedo Z 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,110(8):1458-1466
With the aim of dissecting the genetic determinants of flowering time, vernalization response, and photoperiod sensitivity, we mapped the candidate genes for Vrn-H2 and Vrn-H1 in a facultative × winter barley mapping population and determined their relationships with flowering time and vernalization via QTL analysis. The Vrn-H2 candidate ZCCT-H genes were completely missing from the facultative parent and present in the winter barley parent. This gene was the major determinant of flowering time under long photoperiods in controlled environment experiments, irrespective of vernalization, and under spring-sown field experiments. It was the sole determinant of vernalization response, but the effect of the deletion was modulated by photoperiods when the vernalization requirement was fulfilled. There was no effect under short photoperiods. The Vrn-H1 candidate gene (HvBM5A) was mapped based on a microsatellite polymorphism we identified in the promoter of this gene. Otherwise, the HvBM5A alleles for the two parents were identical. Therefore, the significant flowering time QTL effect associated with this locus suggests tight linkage rather than pleiotropy. This QTL effect was smaller in magnitude than those associated with the Vrn-H2 locus and was significant in two-way interactions with Vrn-H2. The Vrn-H1 locus had no effect on vernalization response. Our results support the Vrn-H2/Vrn-H1 repressor/structural gene model for vernalization response in barley and suggest that photoperiod may also affect the Vrn genes or tightly linked loci. 相似文献
15.
Mapping genes affecting flowering time and frost resistance on chromosome 5B of wheat 总被引:12,自引:0,他引:12
Tóth B Galiba G Fehér E Sutka J Snape JW 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(3):509-514
Two populations of single chromosome recombinant lines were used to map genes controlling flowering time on chromosome 5B of wheat, and one of the populations was also used to map a new frost resistance gene. Genetic maps were developed, mainly using microsatellite markers, and QTL analysis was applied to phenotypic data on the performance of each population collected from growth-room tests of flowering time and frost tolerance. Using a recombinant substitution-line mapping population derived from a cross between the substitution-line 'Chinese Spring' ('Cheyenne' 5B) and 'Chinese Spring' (CS), the gene Vrn-B1, affecting vernalization response, an earliness per se locus, Eps-5BL1, and a gene, Fr-B1, affecting frost resistance, were mapped. Using a 'Hobbit Sib' ('Chinese Spring' 5BL) x 'Hobbit Sib' recombinant substitution line mapping population, an earliness per se locus, Eps-5BL2 was mapped. The Vrn-B1 locus was mapped on the distal portion of the long arm of chromosome 5B, to a region syntenous with the segments of chromosomes 5A and 5D containing Vrn-A1 and Vrn-D1 loci, respectively. The two Eps-5BL loci were mapped close to the centromere with a 16-cM distance from each other, one in agreement with the position of a homoeologous locus previously mapped on chromosome 5H of barley, and suggested by the response of 'Chinese Spring' deletion lines. The Fr-B1 gene was mapped on the long arm of chromosome 5B, 40 cM from the centromeric marker. Previous comparative mapping data with rice chromosome 9 would suggest that this gene could be orthologous to the other Fr genes mapped previously by us on chromosomes 5A or 5D of wheat, although in a more proximal position. This study completes the mapping of these homoeoallelic series of vernalization requirement genes and frost resistance genes on the chromosomes of the homoeologous group 5 in wheat. 相似文献
16.
Jonathan H. Clarke Richard Mithen James K. M. Brown Caroline Dean 《Molecular & general genetics : MGG》1995,248(3):278-286
Quantitative trait loci (QTL) analyses based on restriction fragment length polymorphism maps have been used to resolve the genetic control of flowering time in a cross between twoArabidopsis thaliana ecotypes H51 and Landsbergerecta, differing widely in flowering time. Five quantitative trait loci affecting flowering time were identified in this cross (RLN1-5), four of which are located in regions containing mutations or loci previously identified as conferring a late-flowering phenotype. One of these loci is coincident with theFRI locus identified as the major determinant for late flowering and vernalization responsiveness in theArabidopsis ecotype Stockholm.RLN5, which maps to the lower half of chromosome five (between markers mi69 and m233), only affected flowering time significantly under short day conditions following a vernalization period. The late-flowering phenotype of H51 compared to Landsbergerecta was due to alleles conferring late flowering at only two of the five loci. At the three other loci, H51 possessed alleles conferring early flowering in comparison to those of Landsbergerecta. Combinations of alleles conferring early and late flowering from both parents accounted for the transgressive segregation of flowering time observed within the F2 population. Three QTL,RLN1,RLN2 andRLN3 displayed significant genotype-by-environment interactions for flowering time. A significant interaction between alleles atRLN3 andRLN4 was detected. 相似文献
17.
Jonathan H. Clarke Richard Mithen James K. M. Brown Caroline Dean 《Molecular genetics and genomics : MGG》1995,248(3):278-286
Quantitative trait loci (QTL) analyses based on restriction fragment length polymorphism maps have been used to resolve the genetic control of flowering time in a cross between twoArabidopsis thaliana ecotypes H51 and Landsbergerecta, differing widely in flowering time. Five quantitative trait loci affecting flowering time were identified in this cross (RLN1-5), four of which are located in regions containing mutations or loci previously identified as conferring a late-flowering phenotype. One of these loci is coincident with theFRI locus identified as the major determinant for late flowering and vernalization responsiveness in theArabidopsis ecotype Stockholm.RLN5, which maps to the lower half of chromosome five (between markers mi69 and m233), only affected flowering time significantly under short day conditions following a vernalization period. The late-flowering phenotype of H51 compared to Landsbergerecta was due to alleles conferring late flowering at only two of the five loci. At the three other loci, H51 possessed alleles conferring early flowering in comparison to those of Landsbergerecta. Combinations of alleles conferring early and late flowering from both parents accounted for the transgressive segregation of flowering time observed within the F2 population. Three QTL,RLN1,RLN2 andRLN3 displayed significant genotype-by-environment interactions for flowering time. A significant interaction between alleles atRLN3 andRLN4 was detected. 相似文献
18.
The FLOWERING LOCUS T (FT) gene plays a central role in integrating flowering signals in Arabidopsis because its expression is regulated antagonistically by the photoperiod and vernalization pathways. FT belongs to a family of six genes characterized by a phosphatidylethanolamine-binding protein (PEBP) domain. In rice (Oryza sativa), 19 PEBP genes were previously described, 13 of which are FT-like genes. Five FT-like genes were found in barley (Hordeum vulgare). HvFT1, HvFT2, HvFT3, and HvFT4 were highly homologous to OsFTL2 (the Hd3a QTL), OsFTL1, OsFTL10, and OsFTL12, respectively, and this relationship was supported by comparative mapping. No rice equivalent was found for HvFT5. HvFT1 was highly expressed under long-day (inductive) conditions at the time of the morphological switch of the shoot apex from vegetative to reproductive growth. HvFT2 and HvFT4 were expressed later in development. HvFT1 was therefore identified as the main barley FT-like gene involved in the switch to flowering. Mapping of HvFT genes suggests that they provide important sources of flowering-time variation in barley. HvFTI was a candidate for VRN-H3, a dominant mutation giving precocious flowering, while HvFT3 was a candidate for Ppd-H2, a major QTL affecting flowering time in short days. 相似文献
19.
Pin PA Zhang W Vogt SH Dally N Büttner B Schulze-Buxloh G Jelly NS Chia TY Mutasa-Göttgens ES Dohm JC Himmelbauer H Weisshaar B Kraus J Gielen JJ Lommel M Weyens G Wahl B Schechert A Nilsson O Jung C Kraft T Müller AE 《Current biology : CB》2012,22(12):1095-1101
Life cycle adaptation to latitudinal and seasonal variation in photoperiod and temperature is a major determinant of evolutionary success in flowering plants. Whereas the life cycle of the dicotyledonous model species Arabidopsis thaliana is controlled by two epistatic genes, FLOWERING LOCUS C and FRIGIDA, three unrelated loci (VERNALIZATION) determine the spring and winter habits of monocotyledonous plants such as temperate cereals. In the core eudicot species Beta vulgaris, whose lineage diverged from that leading to Arabidopsis shortly after the monocot-dicot split 140 million years ago, the bolting locus B is a master switch distinguishing annuals from biennials. Here, we isolated B and show that the pseudo-response regulator gene BOLTING TIME CONTROL 1 (BvBTC1), through regulation of the FLOWERING LOCUS T genes, is absolutely necessary for flowering and mediates the response to both long days and vernalization. Our results suggest that domestication of beets involved the selection of a rare partial loss-of-function BvBTC1 allele that imparts reduced sensitivity to photoperiod that is restored by vernalization, thus conferring bienniality, and illustrate how evolutionary plasticity at a key regulatory point can enable new life cycle strategies. 相似文献