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1.
Mol Genet Genomics ; 296(2): 379-390, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33449160

RESUMO

Common bean (Phaseolus vulgaris L.) is a short-day plant and its flowering time, and consequently, pod yield and quality is influenced by photoperiod. In this study, the photoperiodic-sensitive variety 'Hong jin gou', which flowers 31 days (d) earlier in short-day than in long-day, was used as the experimental material. Samples were collected to determine the growth and photosynthetic parameters in each daylength treatment, and transcriptome and metabolome data were conducted. We identified eight genes related to flowering by further screening for differentially expressed genes. These genes function to regulate the biological clock. The combination of differentially expressed genes and metabolites, together with the known regulation network of flowering time and the day-night expression pattern of related genes allow us to speculate on the regulation of flowering time in the common bean and conclude that TIMING OF CAB EXPRESSION1 (TOC1) plays a pivotal role in the network and its upregulation or downregulation causes corresponding changes in the expression of downstream genes. The regulatory network is also influenced by gibberellic acid (GA) and jasmonic acid (JA). These regulatory pathways jointly comprise the flowering regulatory network in common bean.


Assuntos
Perfilação da Expressão Gênica/métodos , Metabolômica/métodos , Phaseolus/fisiologia , Fatores de Transcrição/genética , Relógios Biológicos , Flores/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Giberelinas/farmacologia , Ácidos Linoleicos/farmacologia , Phaseolus/genética , Phaseolus/metabolismo , Fotoperíodo , Proteínas de Plantas/genética , Análise de Sequência de RNA
2.
PLoS One ; 15(12): e0235028, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33362256

RESUMO

Cyclocephalini beetles of the genus Cyclocephala (Coleoptera: Melolonthidae: Dynastinae) use flowers of some plants as food, shelter, and mating sites. However, little is known about floral scent chemistry involved in this interaction. Here we show that a sesquiterpene alcohol mediates attraction of Cyclocephala paraguayensis Arrow, on bottle gourd flowers, Lagenaria siceraria (Cucurbitaceae). Both males and females started to aggregate on the flowers at twilight; after that, mating began and remained for the entire night. GC-FID/EAD analysis of the L. siceraria floral scent collected in the field revealed that only the major constituent of the airborne volatiles elicited electroantennographic responses on male and female antennae of C. paraguayensis. This compound was identified as (3S,6E)-nerolidol, which was tested in two field trapping trials in Brazil. In the first bioassay, traps baited with nerolidol (mix of isomers) captured significantly more adult C. paraguayensis than control traps. In the second field trial, catches in traps baited with a mixture of isomers or enantiopure nerolidol were significantly higher than captures in control traps, but the treatments did not differ significantly. Analysis from the gut content of adult C. paraguayensis showed the presence of pollen, suggesting that they also use bottle gourd flowers for their nourishment. Taken together, these results suggest that (3S,6E)-nerolidol plays an essential role in the reproductive behavior of C. paraguayensis by eliciting aggregation, mating, and feeding.


Assuntos
Besouros/fisiologia , Cucurbita/metabolismo , Sesquiterpenos/metabolismo , Animais , Brasil , Besouros/metabolismo , Cucurbita/fisiologia , Cucurbitaceae/metabolismo , Cucurbitaceae/fisiologia , Feminino , Flores/fisiologia , Masculino , Odorantes/análise , Feromônios/análise , Pólen/fisiologia , Polinização , Sesquiterpenos/análise
3.
PLoS One ; 15(12): e0237484, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332351

RESUMO

Livestock grazing and non-native plant species affect rangeland habitats globally. These factors may have important effects on ecosystem services including pollination, yet, interactions between pollinators, grazing, and invasive plants are poorly understood. To address this, we tested the hypothesis that cattle grazing and site colonization by cheatgrass (Bromus tectorum) impact bee foraging and nesting habitats, and the biodiversity of wild bee communities, in a shortgrass prairie system. Bee nesting habitats (litter and wood cover) were marginally improved in non-grazed sites with low cheatgrass cover, though foraging habitat (floral cover and richness, bare soil) did not differ among cattle-grazed sites or non-grazed sites with low or high cheatgrass cover. However, floral cover was a good predictor of bee abundance and functional dispersion. Mean bee abundance, richness, diversity and functional diversity were significantly lower in cattle-grazed habitats than in non-grazed habitats. Differences in bee diversity among habitats were pronounced early in the growing season (May) but by late-season (August) these differences eroded as Melissodes spp. and Bombus spp. became more abundant at study sites. Fourth-corner analysis revealed that sites with high floral cover tended to support large, social, polylectic bees; sites with high grass cover tended to support oligolectic solitary bees. Both cattle-grazed sites and sites with high cheatgrass cover were associated with lower abundances of above-ground nesting bees but higher abundance of below-ground nesters than non-grazed sites with low cheatgrass cover. We conclude that high cheatgrass cover is not associated with reduced bee biodiversity or abundance, but cattle grazing was negatively associated with bee abundances and altered species composition. Although floral cover is an important predictor of bee assemblages, this was not impacted by cattle grazing and our study suggests that cattle likely impact bee communities through effects other than those mediated by forbs, including soil disturbance or nest destruction. Efforts aimed at pollinator conservation in prairie habitats should focus on managing cattle impacts early in the growing season to benefit sensitive bee species.


Assuntos
Abelhas/fisiologia , Gado/fisiologia , Polinização/fisiologia , Animais , Biodiversidade , Bromus/fisiologia , Bovinos , Ecossistema , Flores/fisiologia , Pradaria , Plantas , Estações do Ano
4.
Proc Natl Acad Sci U S A ; 117(37): 23125-23130, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868415

RESUMO

Many plants use environmental cues, including seasonal changes of day length (photoperiod), to control their flowering time. Under inductive conditions, FLOWERING LOCUS T (FT) protein is synthesized in leaves, and FT protein is a mobile signal, which is able to travel to the shoot apex to induce flowering. Dodders (Cuscuta, Convolvulaceae) are root- and leafless plants that parasitize a large number of autotrophic plant species with varying flowering time. Remarkably, some dodder species, e.g., Cuscuta australis, are able to synchronize their flowering with the flowering of their hosts. Detailed sequence inspection and expression analysis indicated that the FT gene in dodder C. australis very likely does not function in activating flowering. Using soybean host plants cultivated under inductive and noninductive photoperiod conditions and soybean and tobacco host plants, in which FT was overexpressed and knocked out, respectively, we show that FT-induced flowering of the host is likely required for both host and parasite flowering. Biochemical analysis revealed that host-synthesized FT signals are able to move into dodder stems, where they physically interact with a dodder FD transcription factor to activate dodder flowering. This study demonstrates that FTs can function as an important interplant flowering signal in host-dodder interactions. The unique means of flowering regulation of dodder illustrates how regressive evolution, commonly found in parasites, may facilitate the physiological synchronization of parasite and host, here allowing the C. australis parasite to time reproduction exactly with that of their hosts, likely optimizing parasite fitness.


Assuntos
Cuscuta/fisiologia , Cuscuta/parasitologia , Flores/fisiologia , Flores/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/fisiologia , Animais , Regulação da Expressão Gênica de Plantas/fisiologia , Folhas de Planta/parasitologia , Folhas de Planta/fisiologia , Soja/parasitologia , Soja/fisiologia , Tabaco/parasitologia , Tabaco/fisiologia , Fatores de Transcrição/metabolismo
5.
J Plant Res ; 133(6): 873-881, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32997284

RESUMO

Some evolutionary radiations produce a number of closely-related species that continue to coexist. In such plant systems, when pre-pollination barriers are weak, relatively strong post-pollination reproductive barriers are required to maintain species boundaries. Even when post-pollination barriers are in place, however, reproductive interference and pollinator dependence may strengthen selection for pre-pollination barriers. We assessed whether coexistence of species from the unusually speciose Erica genus in the fynbos biome, South Africa, is enabled through pre-pollination or post-pollination barriers. We also tested for reproductive interference and pollinator dependence. We investigated this in natural populations of three bird-pollinated Erica species (Erica plukenetii, E. curviflora and E. coccinea), which form part of a large guild of congeneric species that co-flower and share a single pollinator species (Orange-breasted Sunbird Anthobaphes violacea). At least two of the three pre-pollination barriers assessed (distribution ranges, flowering phenology and flower morphology) were weak in each species pair. Hand-pollination experiments revealed that seed set from heterospecific pollination (average 8%) was significantly lower than seed set from outcross pollination (average 50%), supporting the hypothesis that species boundaries are maintained through post-pollination barriers. Reproductive interference, assessed in one population by applying outcross pollen three hours after applying heterospecific pollen, significantly reduced seed set compared to outcross pollen alone. This may drive selection for traits that enhance pre-pollination barriers, particularly given that two of the three species were self-sterile, and therefore pollinator dependent. This study suggests that post-pollination reproductive barriers could facilitate the coexistence of congeneric species, in a recent radiation with weak pre-pollination reproductive barriers.


Assuntos
Ericaceae/fisiologia , Flores/fisiologia , Polinização , Animais , Aves , Pólen , Reprodução , Especificidade da Espécie
6.
J Plant Res ; 133(6): 883-895, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32929552

RESUMO

The tapetum plays important roles in anther development by providing materials for pollen-wall formation and nutrients for pollen development. Here, we report the characterization of a male-sterile mutant of glycine-rich protein 2 (OsGRP2), which exhibits irregular cell division and dysfunction of the tapetum. GRP is a cellwall structural protein present in the cell walls of diverse plant species, but its function is unclear in pollen development. We found that few GRP genes are expressed in rice and thus focused on one highly expressed gene, OsGRP2. The tapetal cell walls of an OsGRP2 mutant did not thicken at the pollen mothercell stage, as a result, pollen maturation and fertility rate decreased. High OsGRP2 expression was detected in male-floral organs, and OsGRP2 was distributed in the tapetum. OsGRP2 participated in establishment of the cellwall network during early tapetum development. In conclusion, our results indicate that OsGRP2 plays important roles in the differentiation and function of the tapetum.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/fisiologia , Proteínas de Plantas/fisiologia , Pólen/fisiologia , Diferenciação Celular , Parede Celular , Flores/fisiologia , Glicina , Proteínas de Plantas/genética
7.
Nat Commun ; 11(1): 4019, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782255

RESUMO

Phenotypic plasticity, the ability of a genotype of producing different phenotypes when exposed to different environments, may impact ecological interactions. We study here how within-individual plasticity in Moricandia arvensis flowers modifies its pollination niche. During spring, this plant produces large, cross-shaped, UV-reflecting lilac flowers attracting mostly long-tongued large bees. However, unlike most co-occurring species, M. arvensis keeps flowering during the hot, dry summer due to its plasticity in key vegetative traits. Changes in temperature and photoperiod in summer trigger changes in gene expression and the production of small, rounded, UV-absorbing white flowers that attract a different assemblage of generalist pollinators. This shift in pollination niche potentially allows successful reproduction in harsh conditions, facilitating M. arvensis to face anthropogenic perturbations and climate change.


Assuntos
Adaptação Fisiológica , Ecossistema , Flores/fisiologia , Polinização , Animais , Abelhas , Brassicaceae/genética , Brassicaceae/fisiologia , Flores/genética , Regulação da Expressão Gênica de Plantas , Interação Gene-Ambiente , Estações do Ano
9.
PLoS Biol ; 18(7): e3000782, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32692742

RESUMO

Tight regulation of gene transcription and mRNA splicing is essential for plant growth and development. Here we demonstrate that a plant-specific protein, EMBRYO DEFECTIVE 1579 (EMB1579), controls multiple growth and developmental processes in Arabidopsis. We demonstrate that EMB1579 forms liquid-like condensates both in vitro and in vivo, and the formation of normal-sized EMB1579 condensates is crucial for its cellular functions. We found that some chromosomal and RNA-related proteins interact with EMB1579 compartments, and loss of function of EMB1579 affects global gene transcription and mRNA splicing. Using floral transition as a physiological process, we demonstrate that EMB1579 is involved in FLOWERING LOCUS C (FLC)-mediated repression of flowering. Interestingly, we found that EMB1579 physically interacts with a homologue of Drosophila nucleosome remodeling factor 55-kDa (p55) called MULTIPLE SUPPRESSOR OF IRA 4 (MSI4), which has been implicated in repressing the expression of FLC by forming a complex with DNA Damage Binding Protein 1 (DDB1) and Cullin 4 (CUL4). This complex, named CUL4-DDB1MSI4, physically associates with a CURLY LEAF (CLF)-containing Polycomb Repressive Complex 2 (CLF-PRC2). We further demonstrate that EMB1579 interacts with CUL4 and DDB1, and EMB1579 condensates can recruit and condense MSI4 and DDB1. Furthermore, emb1579 phenocopies msi4 in terms of the level of H3K27 trimethylation on FLC. This allows us to propose that EMB1579 condensates recruit and condense CUL4-DDB1MSI4 complex, which facilitates the interaction of CUL4-DDB1MSI4 with CLF-PRC2 and promotes the role of CLF-PRC2 in establishing and/or maintaining the level of H3K27 trimethylation on FLC. Thus, we report a new mechanism for regulating plant gene transcription, mRNA splicing, and growth and development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Proteínas de Ligação ao Cálcio/metabolismo , Desenvolvimento Vegetal/genética , Processamento de RNA/genética , Transcrição Genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação ao Cálcio/genética , Núcleo Celular/metabolismo , Flores/fisiologia , Histonas/metabolismo , Mutação com Perda de Função , Lisina/metabolismo , Metilação , Proteínas Nucleares/metabolismo , Fenótipo , Raízes de Plantas/citologia , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sequências Repetitivas de Aminoácidos
10.
J Vis Exp ; (160)2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32628154

RESUMO

Self-incompatibility in Rosaceae is determined by a Gametophytic Self-Incompatibility System (GSI) that is mainly controlled by the multiallelic locus S. In apricot, the determination of self- and inter-(in)compatibility relationships is increasingly important, since the release of an important number of new cultivars has resulted in the increase of cultivars with unknown pollination requirements. Here, we describe a methodology that combines the determination of self-(in)compatibility by hand-pollinations and microscopy with the identification of the S-genotype by PCR analysis. For self-(in)compatibility determination, flowers at balloon stage from each cultivar were collected in the field, hand-pollinated in the laboratory, fixed, and stained with aniline blue for the observation of pollen tube behavior under the fluorescence microscopy. For the establishment of incompatibility relationships between cultivars, DNA from each cultivar was extracted from young leaves and S-alleles were identified by PCR. This approach allows establishing incompatibility groups and elucidate incompatibility relationships between cultivars, which provides a valuable information to choose suitable pollinizers in the design of new orchards and to select appropriate parents in breeding programs.


Assuntos
Polinização , Prunus armeniaca/fisiologia , DNA de Plantas/análise , Flores/fisiologia , Genótipo , Microscopia de Fluorescência , Folhas de Planta/genética , Pólen/fisiologia , Reação em Cadeia da Polimerase , Prunus armeniaca/genética
11.
PLoS One ; 15(7): e0235347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645033

RESUMO

In most temperate fruit trees, fruits are located on one-year old shoots. In Prunus species, flowers and fruits are born in axillary position along those shoots. The axillary bud fate and branching patterns are thus key components of the cultivar potential fruit production. The objective of this study was to analyze the branching and bearing behaviors of 1-year-old shoots of apricot cultivars and clones genetically closely related. Shoot structures were analyzed in terms of axillary bud fates using hidden semi-Markov chains and compared depending on the genotype, year and shoot length. The shoots were composed of three successive zones containing latent buds (basal zone), central flower buds (median zone) and vegetative buds (distal zone), respectively. The last two zones contained few associated flower buds. The zones length (in number of metamers) and occurrence strongly depended on shoot development in the two successive years. With decrease in the number of metamers per shoot, the last two zones become shorter or may not develop. While the number of metamers of the basal and distal zones and the number of associated flower buds correlated to the number of metamers of the shoot, the number of metamers of the median zone and the transition probability from the median to the distal zone were cultivar specific.


Assuntos
Modelos Biológicos , Brotos de Planta/fisiologia , Prunus armeniaca/genética , Prunus armeniaca/fisiologia , Flores/fisiologia , Frutas/fisiologia , Genótipo , Cadeias de Markov , Estatísticas não Paramétricas
12.
Sci Rep ; 10(1): 9476, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32528048

RESUMO

Intraspecific floral colour polymorphism is a common trait of food deceptive orchids, which lure pollinators with variable, attractive signals, without providing food resources. The variable signals are thought to hinder avoidance learning of deceptive flowers by pollinators. Here, we analysed the cognitive mechanisms underlying the choice of free-flying stingless bees Scaptotrigona aff. depilis trained to visit a patch of artificial flowers that displayed the colours of Ionopsis utricularioides, a food deceptive orchid. Bees were trained in the presence of a non-rewarding colour and later tested with that colour vs. alternative colours. We simulated a discrete-polymorphism scenario with two distinct non-rewarding test colours, and a continuous-polymorphism scenario with three non-rewarding test colours aligned along a chromatic continuum. Bees learned to avoid the non-rewarding colour experienced during training. They thus preferred the novel non-rewarding colour in the discrete-polymorphic situation, and generalized their avoidance to the adjacent colour of the continuum in the continuous-polymorphism situation, favouring thereby the most distant colour. Bees also visited less flowers and abandoned faster a non-rewarding monomorphic patch than a non-rewarding polymorphic patch. Our cognitive analyses thus reveal that variable deceptive orchids disrupt avoidance learning by pollinators and exploit their generalization abilities, which make them favour distinct morphs.


Assuntos
Abelhas/fisiologia , Cognição/fisiologia , Comportamento Alimentar/fisiologia , Polinização/fisiologia , Animais , Aprendizagem da Esquiva/fisiologia , Cor , Flores/fisiologia , Orchidaceae/fisiologia , Pólen/fisiologia
13.
PLoS One ; 15(5): e0233120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421736

RESUMO

Day length is a determinant of flowering time in rice. Phytochromes participate in flowering regulation by measuring the number of daylight hours to which the plant is exposed. Here we describe G123, a rice mutant generated by irradiation, which displays insensitivity to the photoperiod and early flowering under both long day and short day conditions. To detect the mutation responsible for the early flowering phenotype exhibited by G123, we generated an F2 population, derived from crossing with the wild-type, and used a pipeline to detect genomic structural variation, initially developed for human genomes. We detected a deletion in the G123 genome that affects the PHOTOPERIOD SENSITIVITY13 (SE13) gene, which encodes a phytochromobilin synthase, an enzyme implicated in phytochrome chromophore biosynthesis. The transcriptomic analysis, performed by RNA-seq, in the G123 plants indicated an alteration in photosynthesis and other processes related to response to light. The expression patterns of the main flowering regulatory genes, such as Ghd7, Ghd8 and PRR37, were altered in the plants grown under both long day and short day conditions. These findings indicate that phytochromes are also involved in the regulation of these genes under short day conditions, and extend the role of phytochromes in flowering regulation in rice.


Assuntos
Flores/metabolismo , Flores/fisiologia , Oryza/genética , Oryza/fisiologia , Fotossíntese/fisiologia , Proteínas de Plantas/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/metabolismo , Fotossíntese/genética , Proteínas de Plantas/genética
14.
Proc Natl Acad Sci U S A ; 117(20): 10921-10926, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32366661

RESUMO

Flower biomass varies widely across the angiosperms. Each plant species invests a given amount of biomass to construct its sex organs. A comparative understanding of how this limited resource is partitioned among primary (male and female structures) and secondary (petals and sepals) sexual organs on hermaphrodite species can shed light on general evolutionary processes behind flower evolution. Here, we use allometries relating different flower biomass components across species to test the existence of broad allocation patterns across the angiosperms. Based on a global dataset with flower biomass spanning five orders of magnitude, we show that heavier angiosperm flowers tend to be male-biased and invest strongly in petals to promote pollen export, while lighter flowers tend to be female-biased and invest more in sepals to insure their own seed set. This result demonstrates that larger flowers are not simple carbon copies of small ones, indicating that sexual selection via male-male competition is an important driver of flower biomass evolution and sex allocation strategies across angiosperms.


Assuntos
Evolução Biológica , Flores/fisiologia , Magnoliopsida/fisiologia , Biomassa , Gentiana , Lepidium , Nymphaea , Orchidaceae , Pólen , Polinização , Sementes , Seleção Genética , Especificidade da Espécie
15.
Nat Commun ; 11(1): 2065, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32358518

RESUMO

Natural environments require organisms to possess robust mechanisms allowing responses to seasonal trends. In Arabidopsis halleri, the flowering regulator AhgFLC shows upregulation and downregulation phases along with long-term past temperature, but the underlying machinery remains elusive. Here, we investigate the seasonal dynamics of histone modifications, H3K27me3 and H3K4me3, at AhgFLC in a natural population. Our advanced modelling and transplant experiments reveal that H3K27me3-mediated chromatin regulation at AhgFLC provides two essential properties. One is the ability to respond to the long-term temperature trends via bidirectional interactions between H3K27me3 and H3K4me3; the other is the ratchet-like character of the AhgFLC system, i.e. reversible in the entire perennial life cycle but irreversible during the upregulation phase. Furthermore, we show that the long-term temperature trends are locally indexed at AhgFLC in the form of histone modifications. Our study provides a more comprehensive understanding of H3K27me3 function at AhgFLC in a complex natural environment.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Cromatina/química , Flores/fisiologia , Histonas/metabolismo , Proteínas de Domínio MADS/genética , Arabidopsis/fisiologia , Epigênese Genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Código das Histonas , Japão , Estações do Ano , Temperatura
16.
Proc Natl Acad Sci U S A ; 117(23): 12784-12790, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32461365

RESUMO

Fruit development normally occurs after pollination and fertilization; however, in parthenocarpic plants, the ovary grows into the fruit without pollination and/or fertilization. Parthenocarpy has been recognized as a highly attractive agronomic trait because it could stabilize fruit yield under unfavorable environmental conditions. Although natural parthenocarpic varieties are useful for breeding Solanaceae plants, their use has been limited, and little is known about their molecular and biochemical mechanisms. Here, we report a parthenocarpic eggplant mutant, pad-1, which accumulates high levels of auxin in the ovaries. Map-based cloning showed that the wild-type (WT) Pad-1 gene encoded an aminotransferase with similarity to Arabidopsis VAS1 gene, which is involved in auxin homeostasis. Recombinant Pad-1 protein catalyzed the conversion of indole-3-pyruvic acid (IPyA) to tryptophan (Trp), which is a reverse reaction of auxin biosynthetic enzymes, tryptophan aminotransferases (TAA1/TARs). The RNA level of Pad-1 gene increased during ovary development and reached its highest level at anthesis stage in WT. This suggests that the role of Pad-1 in WT unpollinated ovary is to prevent overaccumulation of IAA resulting in precocious fruit-set. Furthermore, suppression of the orthologous genes of Pad-1 induced parthenocarpic fruit development in tomato and pepper plants. Our results demonstrated that the use of pad-1 genes would be powerful tools to improve fruit production of Solanaceae plants.


Assuntos
Ácidos Indolacéticos/metabolismo , Mutação com Perda de Função , Partenogênese , Proteínas de Plantas/genética , Solanum melongena/genética , Transaminases/genética , Flores/genética , Flores/metabolismo , Flores/fisiologia , Homeostase , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Solanum melongena/fisiologia , Transaminases/metabolismo
17.
Proc Natl Acad Sci U S A ; 117(21): 11559-11565, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32393622

RESUMO

Pathogens pose significant threats to pollinator health and food security. Pollinators can transmit diseases during foraging, but the consequences of plant species composition for infection is unknown. In agroecosystems, flowering strips or hedgerows are often used to augment pollinator habitat. We used canola as a focal crop in tents and manipulated flowering strip composition using plant species we had previously shown to result in higher or lower bee infection in short-term trials. We also manipulated initial colony infection to assess impacts on foraging behavior. Flowering strips using high-infection plant species nearly doubled bumble bee colony infection intensity compared to low-infection plant species, with intermediate infection in canola-only tents. Both infection treatment and flowering strips reduced visits to canola, but we saw no evidence that infection treatment shifted foraging preferences. Although high-infection flowering strips increased colony infection intensity, colony reproduction was improved with any flowering strips compared to canola alone. Effects of flowering strips on colony reproduction were explained by nectar availability, but effects of flowering strips on infection intensity were not. Thus, flowering strips benefited colony reproduction by adding floral resources, but certain plant species also come with a risk of increased pathogen infection intensity.


Assuntos
Abelhas , Brassica napus , Flores , Infecções Protozoárias em Animais , Animais , Comportamento Apetitivo/fisiologia , Abelhas/parasitologia , Abelhas/fisiologia , Brassica napus/microbiologia , Brassica napus/parasitologia , Crithidia/patogenicidade , Ecossistema , Flores/parasitologia , Flores/fisiologia , Larva/fisiologia , Polinização/fisiologia , Infecções Protozoárias em Animais/fisiopatologia , Infecções Protozoárias em Animais/transmissão
18.
Sci Rep ; 10(1): 8126, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415216

RESUMO

Differential visitation of pollinators due to divergent floral traits can lead to reproductive isolation via assortative pollen flow, which may ultimately be a driving force in plant speciation, particularly in areas of overlap. We evaluate the effects of pollinator behavioral responses to variation of intraspecific floral color and nectar rewards, on reproductive isolation between two hybrid flower color morphs (fuchsia and blue) and their parental species Penstemon roseus and P. gentianoides with a mixed-pollination system. We show that pollinators (bumblebees and hummingbirds) exhibit different behavioral responses to fuchsia and blue morphs, which could result from differential attraction or deterrence. In addition to differences in color (spectral reflectance), we found that plants with fuchsia flowers produced more and larger flowers, produced more nectar and were more visited by pollinators than those with blue flowers. These differences influenced the foraging behavior and effectiveness as pollinators of both bumblebees and hummingbirds, which contributed to reproductive isolation between the two hybrid flower color morphs and parental species. This study demonstrates how differentiation of pollination traits promotes the formation of hybrid zones leading to pollinator shifts and reproductive isolation. While phenotypic traits of fuchsia and red flowers might encourage more efficient hummingbird pollination in a mixed-pollination system, the costs of bumblebee pollination on plant reproduction could be the drivers for the repeated shifts from bumblebee- to hummingbird-mediated pollination.


Assuntos
Abelhas/fisiologia , Flores/fisiologia , Penstemon/classificação , Penstemon/fisiologia , Polinização , Isolamento Reprodutivo , Simpatria/fisiologia , Animais , Abelhas/anatomia & histologia , Evolução Biológica , Cor , Penstemon/anatomia & histologia , Fenótipo , Pólen
19.
BMC Plant Biol ; 20(1): 137, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245411

RESUMO

BACKGROUND: Flower longevity plays an important role in pollen dispersal and reproductive success in plants. In dichogamous plants, the duration of anthesis as well as the time allocated to male and female functions can vary in response to intrinsic factors (e.g., flowering time and resource allocation) and pollination context along a growth season. However, the fitness consequences of phenological dynamics have rarely been examined. This study aims to unravel the potential causes driving variation in flower longevity, duration of sex phases, and phenotypic sex during a flowering season of strongly protandrous Aconitum gymnandrum, and particularly reproductive consequences of the phenological pattern. RESULTS: Population floral sex ratio shifted from completely male at the beginning to completely female at the end of the season, as is common in other protandrous plants. Phenological dynamics of the floral sex ratio and the duration of sex phases caused a shift from femaleness to maleness in the mean phenotypic sex over the whole season. Floral longevity was negatively correlated with flower size and positively affected by temperature. Early flowers within inflorescences rather than early-flowering individuals emphasized the duration of female over male phase. Owing to the dominance of male-phase flowers, early flowering for individual flowers and plants, or female-biased sex resulted in higher pollen deposition per flower and seed set. At the flower level, flower longevity positively affected female reproductive success, while the effect of flower size was negative. By contrast, plant-level female reproductive success was negatively affected by flower longevity but positively correlated to flower size. CONCLUSIONS: The major result of this study lies in elucidating the relationship between variation in phenological sex expression and floral longevity and their fitness consequences of protandrous A. gymnandrum. The contrasting results on female fitness for individual flowers and plants contribute to our current understanding of the adaptive significance of floral longevity.


Assuntos
Aconitum/fisiologia , Flores , Longevidade , Adaptação Fisiológica , Flores/crescimento & desenvolvimento , Flores/fisiologia , Organismos Hermafroditas/fisiologia , Polinização/fisiologia , Reprodução/fisiologia , Estações do Ano , Razão de Masculinidade , Tundra
20.
Mol Phylogenet Evol ; 148: 106825, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32294547

RESUMO

The tribe Pachygoneae consists of four genera with about 40 species, primarily distributed in tropical and subtropical Asia and America, also in Australasia and Africa. This tribe presents an ideal model to investigate the origin of the tropical and subtropical amphi-Pacific disjunction pattern. More specifically, it allows us to test whether the tropical lineages diverged earlier than the subtropical ones during the fragmentation of the boreotropical flora. In this study, we reconstructed the phylogeny of Pachygoneae using five plastid (rbcL, atpB, matK, ndhF, trnL-F) and one nuclear (26S rDNA) DNA regions. Our results indicate that Pachygoneae is not monophyletic unless Cocculus pendulus and Cocculus balfourii are excluded. We resurrected the genus Cebatha to include these two species and established a new tribe for this genus. Within Pachygoneae, the species of Cocculus are distributed in three different clades, among which two are recognized as two distinct genera, Cocculus s.str. and Nephroia resurrected, and one species is transferred into Pachygone. Our molecular dating and ancestral area reconstruction analyses suggest that Pachygoneae began to diversify in tropical Asia around the early-middle Eocene boundary (c. 48 Ma) and expanded into the New World by c. 44 Ma. In the New World, tropical Hyperbaena originated in the late Eocene (c. 40 Ma), whereas the subtropical Cocculus carolinus and Cocculus diversifolius originated later, in the early Oligocene (c. 32  Ma). These two timings correspond with the two climatic cooling intervals, which suggests that the formation and breakup of the boreotropical floral may have been responsible for the amphi-Pacific disjunct distribution within Pachygoneae. One overland migration event from Asia into Australasia appears to have occurred in the early to late Miocene.


Assuntos
Flores/fisiologia , Menispermaceae/classificação , Filogenia , Filogeografia , Teorema de Bayes , Funções Verossimilhança , Fatores de Tempo
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