Flowering-Time Genes Modulate the Response to LEAFY Activity

Abstract Among the genes that control the transition to flowering in Arabidopsis is a large group whose inactivation causes a delay in flowering. It has been difficult to establish different pathways in which the flowering-time genes might act, because mutants with lesions in these genes have very similar phenotypes. Among the putative targets of the flowering-time genes is another group of genes, which control the identity of individual meristems. Overexpression of one of the meristem-identity genes, LEAFY, can cause the precocious generation of flowers and thus early flowering. We have exploited the opposite phenotypes seen in late-flowering mutants and LEAFY overexpressers to clarify the genetic interactions between flowering-time genes and LEAFY. According to epistatic relationships, we can define one class of flowering-time genes that affects primarily the response to LEAFY activity, and another class of genes that affects primarily the transcriptional induction of LEAFY. These observations allow us to expand previously proposed models for the genetic control of flowering time.

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The early-flowering mutant efs is involved in the autonomous promotion pathway of Arabidopsis thaliana

Development ◽

10.1242/dev.126.21.4763 ◽

1999 ◽

Vol 126 (21) ◽

pp. 4763-4770 ◽

Cited By ~ 3

Author(s):

W.J. Soppe ◽

L. Bentsink ◽

M. Koornneef

Keyword(s):

Arabidopsis Thaliana ◽

Flowering Time ◽

Double Mutant ◽

Plant Size ◽

Early Flowering ◽

Wild Type ◽

Late Flowering ◽

Long Day ◽

Short Days ◽

Transition To Flowering

The transition to flowering is a crucial moment in a plant's life cycle of which the mechanism has only been partly revealed. In a screen for early flowering, after mutagenesis of the late-flowering fwa mutant of Arabidopsis thaliana, the early flowering in short days (efs) mutant was identified. Under long-day light conditions, the recessive monogenic efs mutant flowers at the same time as wild type but, under short-day conditions, the mutant flowers much earlier. In addition to its early-flowering phenotype, efs has several pleiotropic effects such as a reduction in plant size, fertility and apical dominance. Double mutant analysis with several late-flowering mutants from the autonomous promotion (fca and fve) and the photoperiod promotion (co, fwa and gi) pathways of flowering showed that efs reduces the flowering time of all these mutants. However, efs is completely epistatic to fca and fve but additive to co, fwa and gi, indicating that EFS is an inhibitor of flowering specifically involved in the autonomous promotion pathway. A vernalisation treatment does not further reduce the flowering time of the efs mutant, suggesting that vernalisation promotes flowering through EFS. By comparing the length of the juvenile and adult phases of vegetative growth for wild-type, efs and the double mutant plants, it is apparent that efs mainly reduces the length of the adult phase.

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Inter-species functional compatibility of the Theobroma cacao and Arabidopsis FT orthologs: 90 million years of functional conservation of meristem identity genes

BMC Plant Biology ◽

10.1186/s12870-021-02982-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

S. F. Prewitt ◽

A. Shalit-Kaneh ◽

S. N. Maximova ◽

M. J. Guiltinan

Keyword(s):

Gene Expression ◽

Tissue Culture ◽

Gene Family ◽

Flowering Time ◽

Molecular Mechanisms ◽

Regulatory Pathways ◽

Late Flowering ◽

Precocious Flowering ◽

Transition To Flowering

Abstract Background In angiosperms the transition to flowering is controlled by a complex set of interacting networks integrating a range of developmental, physiological, and environmental factors optimizing transition time for maximal reproductive efficiency. The molecular mechanisms comprising these networks have been partially characterized and include both transcriptional and post-transcriptional regulatory pathways. Florigen, encoded by FLOWERING LOCUS T (FT) orthologs, is a conserved central integrator of several flowering time regulatory pathways. To characterize the molecular mechanisms involved in controlling cacao flowering time, we have characterized a cacao candidate florigen gene, TcFLOWERING LOCUS T (TcFT). Understanding how this conserved flowering time regulator affects cacao plant’s transition to flowering could lead to strategies to accelerate cacao breeding. Results BLAST searches of cacao genome reference assemblies identified seven candidate members of the CENTRORADIALIS/TERMINAL FLOWER1/SELF PRUNING gene family including a single florigen candidate. cDNA encoding the predicted cacao florigen was cloned and functionally tested by transgenic genetic complementation in the Arabidopsis ft-10 mutant. Transgenic expression of the candidate TcFT cDNA in late flowering Arabidopsis ft-10 partially rescues the mutant to wild-type flowering time. Gene expression studies reveal that TcFT is spatially and temporally expressed in a manner similar to that found in Arabidopsis, specifically, TcFT mRNA is shown to be both developmentally and diurnally regulated in leaves and is most abundant in floral tissues. Finally, to test interspecies compatibility of florigens, we transformed cacao tissues with AtFT resulting in the remarkable formation of flowers in tissue culture. The morphology of these in vitro flowers is normal, and they produce pollen that germinates in vitro with high rates. Conclusion We have identified the cacao CETS gene family, central to developmental regulation in angiosperms. The role of the cacao’s single FT-like gene (TcFT) as a general regulator of determinate growth in cacao was demonstrated by functional complementation of Arabidopsis ft-10 late-flowering mutant and through gene expression analysis. In addition, overexpression of AtFT in cacao resulted in precocious flowering in cacao tissue culture demonstrating the highly conserved function of FT and the mechanisms controlling flowering in cacao.

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Characterization of genes and alleles involved in the control of flowering time in grapevine

10.1101/584268 ◽

2019 ◽

Author(s):

Nadia Kamal ◽

Iris Ochßner ◽

Anna Schwandner ◽

Prisca Viehöver ◽

Ludger Hausmann ◽

...

Keyword(s):

Flowering Time ◽

Candidate Genes ◽

Mapping Population ◽

Early Flowering ◽

Chromosome 1 ◽

Model Organisms ◽

Bud Burst ◽

Perennial Crop ◽

Inflorescence Development ◽

Late Flowering

AbstractGrapevine (Vitis vinifera) is one of the most important perennial crop plants in worldwide. Understanding of developmental processes like flowering, which impact quality and quantity of yield in this species is therefore of high interest. This gets even more important when considering some of the expected consequences of climate change. Earlier bud burst and flowering, for example, may result in yield loss due to spring frost. Berry ripening under higher temperatures will impact wine quality. Knowledge of interactions between a genotype or allele combination and the environment can be used for the breeding of genotypes that are better adapted to new climatic conditions. To this end, we have generated a list of more than 500 candidate genes that may play a role in the timing of flowering. The grapevine genome was exploited for flowering time control gene homologs on the basis of functional data from model organisms likeA. thaliana. In a previous study, a mapping population derived from early flowering GF.GA-47-42 and late flowering ‘Villard Blanc’ was analyzed for flowering time QTLs. In a second step we have now established a workflow combining amplicon sequencing and bioinformatics to follow alleles of selected candidate genes in the F1individuals and the parental genotypes. Allele combinations of these genes in individuals of the mapping population were correlated with early or late flowering phenotypes. Specific allele combinations of flowering time candidate genes within and outside of the QTL regions for flowering time on chromosome 1, 4, 14, 17, and 18 were found to be associated with an early flowering phenotype. In addition, expression of many of the flowering candidate genes was analyzed over consecutive stages of bud and inflorescence development indicating functional roles of these genes in the flowering control network.

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GWAS unveils features between early- and late-flowering pearl millets

10.21203/rs.3.rs-25381/v2 ◽

2020 ◽

Author(s):

Oumar Diack ◽

Ghislain Kanfany ◽

Mame Codou Gueye ◽

Ousmane Sy ◽

Amadou Fofana ◽

...

Keyword(s):

Flowering Time ◽

Candidate Genes ◽

Plant Height ◽

Pearl Millet ◽

Early Flowering ◽

P Value ◽

Phenotypic Traits ◽

Gene Pools ◽

Climate Change Scenarios ◽

Late Flowering

Abstract Background: Pearl millet, a dietary food for around 100 million people in Africa and in India, has a large diversity due to an extensive genetic diversity combined with a high degree of admixture with wild relatives. In Senegal, two major morphotypes are distinguished: early-flowering and late-flowering millets. The phenotypic variabilities according to the flowering time plays an important role in pearl millet adaptation to climate variability. A better understanding of the genetic makeup of these variabilities would allow breeding of pearl millet fitting different climatic areas. In this study, we aimed to characterize the genetic basis of these phenotypic differences. Results: We defined a core collection capturing most of the diversity of cultivated pearl millet of Senegal, which includes 60 early-flowering Souna and 31 late-flowering Sanio. This panel was evaluated during the 2016 and 2017 rainy seasons at Nioro for 16 agro-morphological traits. Phenological and phenotypic traits linked with yield, flowering time, and biomass helped differentiated early- and late-flowering millets. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) with minor allele frequencies of more than 5% were identified. Sparse Non-Negative Matrix Factorization (sNMF) analysis confirms the genetic structure in two gene pools associated with flowering time differences. Moreover, two chromosomal regions on linkage groups (LG 3) (~89.7Mb) and (LG 6) (~68.1Mb) differentiated the early-flowering into two clusters. Genome-wide association study (GWAS) was used to associate phenotypic variation to the SNPs and 18 genes were linked to flowering time, plant height, nodal tiller number, and biomass (P-value ˂ 2.3E-06). Conclusions: The diversity of early- and late-flowering pearl millet landraces of Senegal was captured using a heuristic approach. Key phenology and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were implicated as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes would have paramount importance in breeding strategies under climate change scenarios.

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GWAS unveils features between early- and late-flowering pearl millets

BMC Genomics ◽

10.1186/s12864-020-07198-2 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Oumar Diack ◽

Ghislain Kanfany ◽

Mame Codou Gueye ◽

Ousmane Sy ◽

Amadou Fofana ◽

...

Keyword(s):

Flowering Time ◽

Candidate Genes ◽

Plant Height ◽

Pearl Millet ◽

Climatic Variability ◽

Early Flowering ◽

Phenotypic Traits ◽

Gene Pools ◽

Late Flowering ◽

A Genome

Abstract Background Pearl millet, a nutritious food for around 100 million people in Africa and India, displays extensive genetic diversity and a high degree of admixture with wild relatives. Two major morphotypes can be distinguished in Senegal: early-flowering Souna and late-flowering Sanio. Phenotypic variabilities related to flowering time play an important role in the adaptation of pearl millet to climate variability. A better understanding of the genetic makeup of these variabilities would make it possible to breed pearl millet to suit regions with different climates. The aim of this study was to characterize the genetic basis of these phenotypic differences. Results We defined a core collection that captures most of the diversity of cultivated pearl millets in Senegal and includes 60 early-flowering Souna and 31 late-flowering Sanio morphotypes. Sixteen agro-morphological traits were evaluated in the panel in the 2016 and 2017 rainy seasons. Phenological and phenotypic traits related with yield, flowering time, and biomass helped differentiate early- and late-flowering morphotypes. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) markers with more than 5% of minor allele frequencies were discovered. Sparse non-negative matrix factorization (sNMF) analysis confirmed the genetic structure in two gene pools associated with differences in flowering time. Two chromosomal regions on linkage groups (LG 3) (~ 89.7 Mb) and (LG 6) (~ 68.1 Mb) differentiated two clusters among the early-flowering Souna. A genome-wide association study (GWAS) was used to link phenotypic variation to the SNPs, and 18 genes were linked to flowering time, plant height, tillering, and biomass (P-value < 2.3E-06). Conclusions The diversity of early- and late-flowering pearl millet morphotypes in Senegal was captured using a heuristic approach. Key phenological and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass yield and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were inferred as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes will be of paramount importance in breeding for resilience to climatic variability.

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A LONG-DAY GENE FOR FLOWERING TIME IN LACTUCA

HortScience ◽

10.21273/hortsci.25.9.1168g ◽

1990 ◽

Vol 25 (9) ◽

pp. 1168g-1168 ◽

Cited By ~ 1

Author(s):

Edward J. Ryder

Keyword(s):

Flowering Time ◽

Single Gene ◽

Early Flowering ◽

Evolutionary Significance ◽

Major Genes ◽

Late Flowering ◽

Long Day ◽

Quantitative Manner ◽

Discrete Effect ◽

Short Days

Genes for flowering time appear to be relatively common in lettuce and other Lactuca species. These include previously described major genes Ef-1 an Ef-2, other genes of discrete effect and genes acting in a quantitative manner. Our goals in studying the flowering time phenomenon are: 1)describe the inheritance of the traits, 2) establish their relationship to each other, and 3) elucidate their evolutionary significance.The PI 175735 (L. serriola) is an accession with narrow leaves, spines and anthocyanin. Its flowering time is daylength related; it is early flowering under long days and late flowering under short days. It was crossed with the late flowering line C-2-1-1, which is homozygous for both late alleles in the Ef system. The F1 is late under short days and early under long days. The F2 population and F3 families were grown under long day conditions in the greenhouse, Segregation in the F2 was 3 early: 1 late. Among F3 families from early plants, segregation was 1 homozygous early: 2 segregating. Within segregating families, the ratio was again 3:1. The evidence suggests a single gene with earliness dominant.

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A systematic comparison of morphology and seed proteins of early- and late-flowering forms of Medicago scutellata

Canadian Journal of Botany ◽

10.1139/b93-021 ◽

1993 ◽

Vol 71 (1) ◽

pp. 183-192

Author(s):

Ernest Small ◽

Gary R. Bauchan ◽

Rosemary Salter ◽

Brenda Brookes ◽

Geoff C. Auricht

Keyword(s):

Flowering Time ◽

Polyacrylamide Gel Electrophoresis ◽

Seed Proteins ◽

Bimodal Distribution ◽

Early Flowering ◽

Distribution Area ◽

Mediterranean Islands ◽

Form Analysis ◽

Late Flowering ◽

Medicago Scutellata

Two hundred and thirty-nine germ plasm accessions of Medicago scutellata grown under greenhouse conditions exhibited a strongly bimodal distribution of flowering time. Numerical taxonomic analysis showed that the early- and late-flowering forms are substantially different morphologically. The early-flowering form is smaller and less vigorous, has fewer flowers in the inflorescence, and fewer serrations on the leaf blades and stipules than the late-flowering form. Analysis of seed proteins using polyacrylamide gel electrophoresis identified 11 seed proteins that can be used to distinguish the two forms and putative hybrids. Although both forms appear widespread in the circum-Mediterranean indigenous distribution area, only about one-third of the accessions represented the early-flowering form, which seemed to predominate only on isolated Mediterranean islands. The two forms may merit infraspecific taxonomic recognition. Key words: Medicago scutellata, Fabaceae, taxonomy, classification, systematics, seed proteins, electrophoresis, flowering time.

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A LONG-DAY GENE FOR FLOWERING TIME IN LACTUCA

HortScience ◽

10.21273/hortsci.25.9.1168 ◽

1990 ◽

Vol 25 (9) ◽

pp. 1168G-1168

Author(s):

Edward J. Ryder

Keyword(s):

Flowering Time ◽

Single Gene ◽

Early Flowering ◽

Evolutionary Significance ◽

Major Genes ◽

Late Flowering ◽

Long Day ◽

Quantitative Manner ◽

Discrete Effect ◽

Short Days

Genes for flowering time appear to be relatively common in lettuce and other Lactuca species. These include previously described major genes Ef-1 an Ef-2, other genes of discrete effect and genes acting in a quantitative manner. Our goals in studying the flowering time phenomenon are: 1)describe the inheritance of the traits, 2) establish their relationship to each other, and 3) elucidate their evolutionary significance. The PI 175735 (L. serriola) is an accession with narrow leaves, spines and anthocyanin. Its flowering time is daylength related; it is early flowering under long days and late flowering under short days. It was crossed with the late flowering line C-2-1-1, which is homozygous for both late alleles in the Ef system. The F1 is late under short days and early under long days. The F2 population and F3 families were grown under long day conditions in the greenhouse, Segregation in the F2 was 3 early: 1 late. Among F3 families from early plants, segregation was 1 homozygous early: 2 segregating. Within segregating families, the ratio was again 3:1. The evidence suggests a single gene with earliness dominant.

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GWAS unveils features between early- and late-flowering pearl millets

10.21203/rs.3.rs-25381/v1 ◽

2020 ◽

Author(s):

Oumar Diack ◽

Ghislain Kanfany ◽

Mame Codou Gueye ◽

Ousmane Sy ◽

Amadou Fofana ◽

...

Keyword(s):

Flowering Time ◽

Candidate Genes ◽

Plant Height ◽

Pearl Millet ◽

Early Flowering ◽

P Value ◽

Phenotypic Traits ◽

Gene Pools ◽

Climate Change Scenarios ◽

Late Flowering

Abstract Background Pearl millet, a dietary food for around 100 million people in Africa and in India, has a large diversity due to an extensive genetic diversity combined with a high degree of admixture with wild relatives. In Senegal, two major morphotypes are distinguished: early-flowering and late-flowering millets. The phenotypic variabilities according to the flowering time plays an important role in pearl millet adaptation to climate variability. A better understanding of the genetic makeup of these variabilities would allow breeding of pearl millet fitting different climatic areas. In this study, we aimed to characterize the genetic basis of these phenotypic differences. Results We defined a core collection capturing most of the diversity of cultivated pearl millet of Senegal, which includes 60 early-flowering Souna and 31 late-flowering Sanio. This panel was evaluated during the 2016 and 2017 rainy seasons at Nioro for 16 agro-morphological traits. Phenological and phenotypes traits linked with yield, flowering time, and biomass helped differentiated early- and late-flowering millets. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) with minor allele frequencies of more than 5% were identified. Sparse Non-Negative Matrix Factorization (sNMF) analysis confirms the genetic structure in 2 gene pools associated with flowering time differences. Moreover, 2 chromosomal regions on linkage groups 3 (~ 89.7 Mb) and 6 (~ 68.1 Mb) differentiated the early-flowering into 2 clusters. Genome-wide analysis study (GWAS) was used to associate phenotypic variation to the SNPs and 18 genes were linked to flowering time, plant height, nodal tiller number, and biomass (P-value ˂ 2.3E-06). Conclusions The diversity of early- and late-flowering pearl millet landraces of Senegal was captured using a heuristic approach. Key phenology and phenotypic traits, SNPs, ad candidate genes underlying flowering time, tillering, biomass and plant height of pearl millet were identified. Chromosome rearrangements in LG 3 and 6 were implicated as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes would have paramount importance in breeding strategies under climate change scenarios.

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GWAS unveils features between early- and late-flowering pearl millets

10.21203/rs.3.rs-25381/v3 ◽

2020 ◽

Author(s):

Oumar Diack ◽

Ghislain Kanfany ◽

Mame Codou Gueye ◽

Ousmane Sy ◽

Amadou Fofana ◽

...

Keyword(s):

Flowering Time ◽

Candidate Genes ◽

Plant Height ◽

Pearl Millet ◽

Climatic Variability ◽

Early Flowering ◽

Phenotypic Traits ◽

Gene Pools ◽

Late Flowering ◽

A Genome

Abstract Background: Pearl millet, a nutritious food for around 100 million people in Africa and India, displays extensive genetic diversity and a high degree of admixture with wild relatives. Two major morphotypes can be distinguished in Senegal: early-flowering Souna and late-flowering Sanio. Phenotypic variabilities related to flowering time play an important role in the adaptation of pearl millet to climate variability. A better understanding of the genetic makeup of these variabilities would make it possible to breed pearl millet to suit regions with different climates. The aim of this study was to characterize the genetic basis of these phenotypic differences.Results: We defined a core collection that captures most of the diversity of cultivated pearl millets in Senegal and includes 60 early-flowering Souna and 31 late-flowering Sanio morphotypes. Sixteen agro-morphological traits were evaluated in the panel in the 2016 and 2017 rainy seasons. Phenological and phenotypic traits related with yield, flowering time, and biomass helped differentiate early- and late-flowering morphotypes. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) markers with more than 5% of minor allele frequencies were discovered. Sparse non-negative matrix factorization (sNMF) analysis confirmed the genetic structure in two gene pools associated with differences in flowering time. Two chromosomal regions on linkage groups (LG 3) (~89.7Mb) and (LG 6) (~68.1Mb) differentiated two clusters among the early-flowering Souna. A genome-wide association study (GWAS) was used to link phenotypic variation to the SNPs, and 18 genes were linked to flowering time, plant height, tillering, and biomass (P-value ˂ 2.3E-06).Conclusions: The diversity of early- and late-flowering pearl millet morphotypes in Senegal was captured using a heuristic approach. Key phenological and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass yield and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were inferred as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes will be of paramount importance in breeding for resilience to climatic variability.

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