scholarly journals Genetic architecture of floral traits in bee- and hummingbird-pollinated sister species of Aquilegia (columbine)

2021 ◽  
Author(s):  
Molly B. Edwards ◽  
Gary P. T. Choi ◽  
Nathan J. Derieg ◽  
Ya Min ◽  
Angie C. Diana ◽  
...  

Interactions with animal pollinators have helped shape the stunning diversity of flower morphologies across the angiosperms. A common evolutionary consequence of these interactions is that some flowers have converged on suites of traits, or pollination syndromes, that attract and reward specific pollinator groups. Determining the genetic basis of these floral pollination syndromes can help us understand the processes that contributed to the diversification of the angiosperms. Here, we characterize the genetic architecture of a bee-to-hummingbird pollination shift in Aquilegia (columbine) using QTL mapping of 17 floral traits encompassing color, nectar composition, and organ morphology. In this system, we find that the genetic architectures underlying differences in floral color are quite complex, and we identify several likely candidate genes involved in anthocyanin and carotenoid floral pigmentation. Most morphological and nectar traits also have complex genetic underpinnings; however, one of the key floral morphological phenotypes, nectar spur curvature, is shaped by a single locus of large effect.

2020 ◽  
Vol 11 ◽  
Author(s):  
Ezgi Ogutcen ◽  
Karine Durand ◽  
Marina Wolowski ◽  
Laura Clavijo ◽  
Catherine Graham ◽  
...  

Changes in floral pigmentation can have dramatic effects on angiosperm evolution by making flowers either attractive or inconspicuous to different pollinator groups. Flower color largely depends on the type and abundance of pigments produced in the petals, but it is still unclear whether similar color signals rely on same biosynthetic pathways and to which extent the activation of certain pathways influences the course of floral color evolution. To address these questions, we investigated the physical and chemical aspects of floral color in the Neotropical Gesnerioideae (ca. 1,200 spp.), in which two types of anthocyanins, hydroxyanthocyanins, and deoxyanthocyanins, have been recorded as floral pigments. Using spectrophotometry, we measured flower reflectance for over 150 species representing different clades and pollination syndromes. We analyzed these reflectance data to estimate how the Gesnerioideae flowers are perceived by bees and hummingbirds using the visual system models of these pollinators. Floral anthocyanins were further identified using high performance liquid chromatography coupled to mass spectrometry. We found that orange/red floral colors in Gesnerioideae are produced either by deoxyanthocyanins (e.g., apigenidin, luteolinidin) or hydroxyanthocyanins (e.g., pelargonidin). The presence of deoxyanthocyanins in several lineages suggests that the activation of the deoxyanthocyanin pathway has evolved multiple times in the Gesnerioideae. The hydroxyanthocyanin-producing flowers span a wide range of colors, which enables them to be discriminated by hummingbirds or bees. By contrast, color diversity among the deoxyanthocyanin-producing species is lower and mainly represented at longer wavelengths, which is in line with the hue discrimination optima for hummingbirds. These results indicate that Gesnerioideae have evolved two different biochemical mechanisms to generate orange/red flowers, which is associated with hummingbird pollination. Our findings also suggest that the activation of the deoxyanthocyanin pathway has restricted flower color diversification to orange/red hues, supporting the potential constraining role of this alternative biosynthetic pathway on the evolutionary outcome of phenotypical and ecological diversification.


2021 ◽  
Author(s):  
Alessandro L V Coradini ◽  
Fellipe da Silveira Bezerra de Mello ◽  
Monique Furlan ◽  
Carla Maneira ◽  
Marcello Falsarella Carazzolle ◽  
...  

Abstract BACKGROUNDSaccharomyces cerevisiae is largely applied in many biotechnological processes, from traditional food and beverage industries to modern biofuel and biochemicals factories. During the fermentation process, yeast cells are usually challenged in different harsh conditions, which often impact productivity. Regarding bioethanol production, cell exposure to acidic environments is related to productivity loss on both first and second generation ethanol. In this scenario, indigenous strains traditionally used in fermentation stand out as a source of complex genetic architecture, mainly due to their highly robust background - including low pH tolerance. RESULTSIn this work, we pioneer the use of QTL mapping to uncover the genetic basis that endow industrial strain Pedra-2 (PE-2) with outstanding acid resistance. First, we developed a fluorescence-based high-throughput approach to collect a large number of haploid cells using flow cytometry. Then, we were able to apply a bulk segregant analysis to solve the genetic basis of low pH resistance in PE-2, which uncovered a region in chromosome XIII as the major QTL associated with the evaluated phenotype. A reciprocal hemizygosity analysis revealed allele GAS1, encoding a β-1,3-glucanosyltransferase, as the major contributor to this phenotype. The GAS1 sequence alignment of 48 S. cerevisiae strains pointed out a non-synonymous mutation (T211A) prevalence in wild type isolates, which is absent in laboratory strains. We further showcase that GAS1 allele swap between PE-2 and a low pH-susceptible strain can improve cell viability on the latter of up to 12% after a sulfuric acid wash process.CONCLUSIONThis work revealed GAS1 as the major causative gene associated with low pH resistance in PE-2, harboring a non-synonymous mutation persistent in industrial strains. We also showcase how GAS1PE-2 can improve acid resistance of a susceptible strain, suggesting that these findings can be a powerful foundation for the development of more robust and acid-tolerant strains for the industrial production of economically-relevant goods. Our results collectively show the importance of tailored industrial isolated strains in the discovery of the genetic architecture of relevant traits and its implications over productivity.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alessandro L. V. Coradini ◽  
Fellipe da Silveira Bezerra de Mello ◽  
Monique Furlan ◽  
Carla Maneira ◽  
Marcelo F. Carazzolle ◽  
...  

Abstract Background Saccharomyces cerevisiae is largely applied in many biotechnological processes, from traditional food and beverage industries to modern biofuel and biochemicals factories. During the fermentation process, yeast cells are usually challenged in different harsh conditions, which often impact productivity. Regarding bioethanol production, cell exposure to acidic environments is related to productivity loss on both first- and second-generation ethanol. In this scenario, indigenous strains traditionally used in fermentation stand out as a source of complex genetic architecture, mainly due to their highly robust background—including low pH tolerance. Results In this work, we pioneer the use of QTL mapping to uncover the genetic basis that confers to the industrial strain Pedra-2 (PE-2) acidic tolerance during growth at low pH. First, we developed a fluorescence-based high-throughput approach to collect a large number of haploid cells using flow cytometry. Then, we were able to apply a bulk segregant analysis to solve the genetic basis of low pH resistance in PE-2, which uncovered a region in chromosome X as the major QTL associated with the evaluated phenotype. A reciprocal hemizygosity analysis revealed the allele GAS1, encoding a β-1,3-glucanosyltransferase, as the casual variant in this region. The GAS1 sequence alignment of distinct S. cerevisiae strains pointed out a non-synonymous mutation (A631G) prevalence in wild-type isolates, which is absent in laboratory strains. We further showcase that GAS1 allele swap between PE-2 and a low pH-susceptible strain can improve cell viability on the latter of up to 12% after a sulfuric acid wash process. Conclusion This work revealed GAS1 as one of the main causative genes associated with tolerance to growth at low pH in PE-2. We also showcase how GAS1PE-2 can improve acid resistance of a susceptible strain, suggesting that these findings can be a powerful foundation for the development of more robust and acid-tolerant strains. Our results collectively show the importance of tailored industrial isolated strains in discovering the genetic architecture of relevant traits and its implications over productivity.


2015 ◽  
Author(s):  
Hermine Alexandre ◽  
Justine Vrignaud ◽  
Brigitte Mangin ◽  
Simon Joly

Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.


2019 ◽  
Author(s):  
Jamie L. Kostyun ◽  
Matthew J.S. Gibson ◽  
Christian M. King ◽  
Leonie C. Moyle

SummaryGenetic correlations among different components of phenotypes, especially resulting from pleiotropy, can constrain or facilitate trait evolution. These factors could especially influence the evolution of traits that are functionally integrated, such as those comprising the flower. Indeed, pleiotropy is proposed as a main driver of repeated convergent trait transitions, including the evolution of phenotypically-similar pollinator syndromes.We assessed the role of pleiotropy in the differentiation of floral and other reproductive traits between two species —Jaltomata sinuosa and J. umbellata (Solanaceae)—that have divergent suites of floral traits consistent with bee- and hummingbird-pollination, respectively. To do so, we generated a hybrid population and examined the genetic architecture (trait segregation and QTL distribution) underlying 25 floral and fertility traits.We found that most floral traits had a relatively simple genetic basis (few, predominantly additive, QTL of moderate to large effect), as well as little evidence of antagonistic pleiotropy (few trait correlations and QTL co-localization, particularly between traits of different classes). However, we did detect a potential case of adaptive pleiotropy among floral size and nectar traits.These mechanisms may have facilitated the rapid floral trait evolution observed within Jaltomata, and may be a common component of rapid phenotypic change more broadly.


2021 ◽  
Author(s):  
Ajith Ashokan ◽  
Piyakaset Suksathan ◽  
Jana Leong-Škorničková ◽  
Mark Newman ◽  
W. John Kress ◽  
...  

ABSTRACTPREMISEHedychium J.Koenig (ginger lilies: Zingiberaceae) is endemic to the Indo-Malayan Realm (IMR) and is known for its fragrant flowers. Two different pollination syndromes characterize the genus: diurnal or bird pollination and nocturnal or moth pollination systems. To date, no attempt has been undertaken to understand the evolution of floral traits in this genus.METHODSWe estimated ancestral character-states, phylogenetic signals, and character correlations for thirteen discrete and eight continuous floral traits representing 75% species diversity of Hedychium. Diversification rate estimation analyses were also employed to understand trait-dependent diversification in the genus.RESULTSInflorescence structure, cincinnus capacity, and curvature of floral tubes revealed strong phylogenetic dependence, whereas number of open flowers per inflorescence per day, color of the labellum, and exertion of the stigma characterized higher ecological effects. Diversification rate estimations suggested that the labellum width, floral tube length, and labellum color played a major role in the evolutionary diversification of Hedychium.CONCLUSIONSWe identified bract type and cincinnus capacity as synapomorphies for Hedychium, while the island-specific clade III was characterized by slender cylindrical inflorescence, coiling of floral tubes, and longer bract to calyx ratio. The circum-Himalayan clade IV is the most speciose, derived, and with most variable floral traits. Although floral color and size lacked any association with pollinator-specific traits (moth and bird pollination), pale colored flowers were most common in the early diverging clades (clade I, II-el., and II-de.), indicating their ancestral nature, when compared to brightly colored flowers.


Genetics ◽  
2000 ◽  
Vol 156 (3) ◽  
pp. 1379-1392 ◽  
Author(s):  
Thomas Juenger ◽  
Michael Purugganan ◽  
Trudy F C Mackay

Abstract A central question in biology is how genes control the expression of quantitative variation. We used statistical methods to estimate genetic variation in eight Arabidopsis thaliana floral characters (fresh flower mass, petal length, petal width, sepal length, sepal width, long stamen length, short stamen length, and pistil length) in a cosmopolitan sample of 15 ecotypes. In addition, we used genome-wide quantitative trait locus (QTL) mapping to evaluate the genetic basis of variation in these same traits in the Landsberg erecta × Columbia recombinant inbred line population. There was significant genetic variation for all traits in both the sample of naturally occurring ecotypes and in the Ler × Col recombinant inbred line population. In addition, broad-sense genetic correlations among the traits were positive and high. A composite interval mapping (CIM) analysis detected 18 significant QTL affecting at least one floral character. Eleven QTL were associated with several floral traits, supporting either pleiotropy or tight linkage as major determinants of flower morphological integration. We propose several candidate genes that may underlie these QTL on the basis of positional information and functional arguments. Genome-wide QTL mapping is a promising tool for the discovery of candidate genes controlling morphological development, the detection of novel phenotypic effects for known genes, and in generating a more complete understanding of the genetic basis of floral development.


Author(s):  
Yasin Topcu ◽  
Manoj Sapkota ◽  
Eudald Illa-Berenguer ◽  
Savithri U. Nambeesan ◽  
Esther van der Knaap

Abstract Key message Blossom-End Rot is Quantitatively Inherited and Maps to Four Loci in Tomato. Abstract Blossom-end rot (BER) is a devastating physiological disorder that affects tomato and other vegetables, resulting in significant crop losses. To date, most studies on BER have focused on the environmental factors that affect calcium translocation to the fruit; however, the genetic basis of this disorder remains unknown. To investigate the genetic basis of BER, two F2 and F3:4 populations along with a BC1 population that segregated for BER occurrence were evaluated in the greenhouse. Using the QTL-seq approach, quantitative trait loci (QTL) associated with BER Incidence were identified at the bottom of chromosome (ch) 3 and ch11. Additionally, linkage-based QTL mapping detected another QTL, BER3.1, on ch3 and BER4.1 on ch4. To fine map the QTLs identified by QTL-seq, recombinant screening was performed. BER3.2, the major BER QTL on ch3, was narrowed down from 5.68 to 1.58 Mbp with a 1.5-LOD support interval (SI) corresponding to 209 candidate genes. BER3.2 colocalizes with the fruit weight gene FW3.2/SlKLUH, an ortholog of cytochrome P450 KLUH in Arabidopsis. Further, BER11.1, the major BER QTL on ch11, was narrowed down from 3.99 to 1.13 Mbp with a 1.5-LOD SI interval comprising of 141 candidate genes. Taken together, our results identified and fine mapped the first loci for BER resistance in tomato that will facilitate marker-assistant breeding not only in tomato but also in many other vegetables suffering for BER.


2019 ◽  
Author(s):  
Martha L. Serrano-Serrano ◽  
Anna Marcionetti ◽  
Mathieu Perret ◽  
Nicolas Salamin

AbstractThe repeated evolution of convergent floral shapes and colors in angiosperms has been largely interpreted as the response to pollinator-mediated selection to maximize attraction and efficiency of specific groups of pollinators. The genetic mechanisms contributing to certain flower traits have been studied in detail for model system species, but the extent by which flowers are free to vary and how predictable are the genetic changes underlying flower adaptation to pollinator shifts still remain largely unknown.Here, we aimed at detecting the genetic basis of the repeated evolution of flower phenotypes associated with pollinator shifts. We assembled and compared de novo transcriptomes of three phylogenetic independent pairs of Gesneriaceae species, each with contrasting flower phenotype adapted to either bee or hummingbird pollination. We assembled and analyzed a total of 14,059 genes and we showed that changes in expression in 550 of them was associated with the pollination syndromes. Among those, we observed genes with function linked to floral color, scent, shape and symmetry, as well as nectar composition. These genes represent candidates genes involved in the build-up of the convergent floral phenotypes.This study provides the first insights into the molecular mechanisms underlying the repeated evolution of pollination syndromes. Although the presence of additional lineage-specific responses cannot be excluded, these results suggest that the convergent evolution of genes expression is involved in the convergent build-up of the pollination syndromes. Future studies aiming to directly manipulate certain genes will integrate our knowledge on the key genes for floral transitions and the pace of floral evolution.Data availabilityRaw Illumina reads will be available in the Sequence Read Archive (SRA) in NCBI database. The assembled transcriptomes and their annotation will by available in DRYAD repository. Details and accession ID will be provided at the time of the manuscript acceptance.


2015 ◽  
Author(s):  
Hermine Alexandre ◽  
Justine Vrignaud ◽  
Brigitte Mangin ◽  
Simon Joly

Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.


Sign in / Sign up

Export Citation Format

Share Document