In Arabidopsis, a long day flowering plant, CONSTANS (CO) acts as a transcriptional activator of flowering under long day (LD) condition. In rice, a short day flowering plant, Hd1, the ortholog of ...CO, plays dual functions in respond to day-length, activates flowering in short days and represses flowering in long days. In addition, alleles of Hd1 account for ~ 44% of the variation in flowering time observed in cultivated rice and sorghum. How does it work in bamboo? The function of CO in bamboo is similar to that in Arabidopsis?
Two CO homologous genes, PvCO1 and PvCO2, in Phyllostachys violascens were identified. Alignment analysis showed that the two PvCOLs had the highest sequence similarity to rice Hd1. Both PvCO1 and PvCO2 expressed in specific tissues, mainly in leaf. The PvCO1 gene had low expression before flowering, high expression during the flowering stage, and then declined to low expression again after flowering. In contrast, expression of PvCO2 was low during the flowering stage, but rapidly increased to a high level after flowering. The mRNA levels of both PvCOs exhibited a diurnal rhythm. Both PvCO1 and PvCO2 proteins were localized in nucleus of cells. PvCO1 could interact with PvGF14c protein which belonged to 14-3-3 gene family through B-box domain. Overexpression of PvCO1 in Arabidopsis significantly caused late flowering by reducing the expression of AtFT, whereas, transgenic plants overexpressing PvCO2 showed a similar flowering time with WT under LD conditions. Taken together, these results suggested that PvCO1 was involved in the flowering regulation, and PvCO2 may either not have a role in regulating flowering or act redundantly with other flowering regulators in Arabidopsis. Our data also indicated regulatory divergence between PvCOLs in Ph. violascens and CO in Arabidopsis as well as Hd1 in Oryza sativa. Our results will provide useful information for elucidating the regulatory mechanism of COLs involved in the flowering.
Unlike to the CO gene in Arabidopsis, PvCO1 was a negative regulator of flowering in transgenic Arabidopsis under LD condition. It was likely that long period of vegetative growth of this bamboo species was related with the regulation of PvCO1.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Timely flowering is essential for optimum crop reproduction and yield. To determine the best flowering‐time genes (FTGs) relevant to local adaptation and breeding, it is essential to compare ...the interspecific genetic architecture of flowering in response to light and temperature, the two most important environmental cues in crop breeding. However, the conservation and variations of FTGs across species lack systematic dissection. This review summarizes current knowledge on the genetic architectures underlying light and temperature‐mediated flowering initiation in Arabidopsis, rice, and temperate cereals. Extensive comparative analyses show that most FTGs are conserved, whereas functional variations in FTGs may be species specific and confer local adaptation in different species. To explore evolutionary dynamics underpinning the conservation and variations in FTGs, domestication and selection of some key FTGs are further dissected. Based on our analyses of genetic control of flowering time, a number of key issues are highlighted. Strategies for modulation of flowering behavior in crop breeding are also discussed. The resultant resources provide a wealth of reference information to uncover molecular mechanisms of flowering in plants and achieve genetic improvement in crops.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•Co-flowering sympatric plants may act as reciprocal selection pressures.•Phenotypic selection on the phenology of two sympatric species was studied.•Unexpectedly, greater interspecific flowering ...synchrony was favored.•Staggered flowering phenology may be influenced by the abiotic environment.
Staggered flowering phenology in sympatric plant species that share pollinators is often considered the ultimate strategy for avoiding pollinator competition or a facilitative strategy to maintain pollinators throughout the year. Some factors of the abiotic environment may also contribute to the maintenance of staggered flowering. Flowering (a)synchrony among conspecifics is recognized as a trait with selective value. However, little research has addressed phenotypic selection for (a)synchrony with other plant species. Here, I experimentaly examined the flowering phenology of two sympatric congeneric species (Cnidoscolus aconitifolius & C. souzae) that share pollinators and measured phenotypic selection on this trait. Preliminary field observation suggests that these species exhibit staggered flowering, so my main goal was to assess phenotypic selection on flowering (a)synchrony between the two study species (interspecific synchrony). I predicted that the plants that present greater interspecific synchrony would be selected against and would thus contribute to the maintenance of staggered flowering. However, the patterns of phenotypic selection found were counterintuitive: individuals of C. souzae with greater intraspecific synchrony were selected against, while those with greater interspecific synchrony with C. aconitifolius were favoured by phenotypic selection. I also found the opposite pattern of flower production response to temperature in this system, implying that the abiotic environment could partly explain the occurrence of staggered flowering. Since the phenotypic selection found in this study may select against the observed staggered flowering, reciprocal phenotypic selection between co-occurring plants cannot be invoked as a mechanism underlying staggered flowering phenology in these two Cnidoscolus species.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Co‐flowering communities are usually characterized by high plant generalization but knowledge of the underlying factors leading to high levels of generalization and pollinator sharing, and how these ...may contribute to network structure is still limited.
Flowering phenology and floral trait similarity are considered among the most important factors determining plant generalization and pollinator sharing. However, these have been evaluated independently even though they can act in concert with each other. Moreover, the importance of flowering phenology and floral similarity, via their effects on plant generalization, in the structure of plant–pollinator networks has been scarcely studied. Here, we aim to evaluate the effect of flowering phenology and floral similarity in mediating the degree of pollinator sharing and plant generalization in two coastal communities and uncover their importance as drivers of plant–pollinator network structure.
We recorded flower production per species, as well as the identity and frequency of floral visitors along the entire flowering season. We estimated the degree of flowering overlap, the degree of floral similarity (using floral traits associated with size and colour) and the degree of pollinator sharing among plant species within both communities.
Structural equation models (SEM) showed a positive effect of flowering overlap on pollinator sharing and plant generalization. Pollinator sharing and plant generalization positively affected network nestedness. Furthermore, SEM showed a direct positive effect of flowering overlap on network modularity. The SEM analyses also revealed a significant interaction effect of floral similarity and flowering overlap on pollinator sharing, with consequences for network nestedness in one community.
Synthesis. Our results highlight the importance of integrating multiple axes of differentiation such as flowering phenology and floral similarity into our understanding of the drivers of plant–pollinator network structure.
Resumen
Las comunidades co‐florales usualmente se caracterizan por una alta generalización de las plantas en el uso de polinizadores, pero el conocimiento de los factores subyacentes que guían los altos niveles de generalización en la compartición de polinizadores y cómo estos contribuyen a la estructura de las redes aún es limitado.
La fenología de floración y la similitud de atributos florales son considerados entre los factores más importantes que determinan la generalización y la compartición de polinizadores. Sin embargo, aunque estos factores pueden actuar de manera conjunta han sido evaluados de manera independiente. Más aún, la importancia de la fenología de floración y la similitud de atributos florales sobre la estructura de las redes planta‐polinizador, vía sus efectos en la generalización de las plantas, ha sido escasamente estudiada. En este estudio evaluamos el efecto de la fenología de floración y la similitud de atributos florales como mediadores del grado de compartición de polinizadores y la generalización de las plantas en dos comunidades costeras para revelar su importancia como impulsores de la estructura de las redes planta‐polinizador
Registramos la producción de flores para cada especie, así como la identidad y frecuencia de los visitantes florales a lo largo de toda una temporada de floración. Estimamos el grado de sobrelapamiento fenológico de la floración, el grado de similitud de atributos florales (asociados al tamaño y color de las flores), y el grado de compartición de polinizadores entre las especies de plantas en ambas comunidades.
Modelos de ecuaciones estructurales (SEM) mostraron efectos positivos del sobrelapamiento fenológico de la floración sobre la compartición de polinizadores y la generalización de las plantas. La compartición de polinizadores y la generalización de las plantas afectaron positivamente el anidamiento de la red. Más aún, el SEM mostró un efecto positivo directo sobre la modularidad de las redes. El análisis SEM también reveló en una de las comunidades una interacción significativa entre la similitud de atributos florales y el sobrelapamiento fenológico de la floración en la compartición de polinizadores con consecuencias en el anidamiento de la red.
Síntesis. Nuestros resultados resaltan la importancia de integrar múltiples ejes de diferenciación como la fenología de floración y la similitud floral para avanzar en nuestro entendimiento de los factores impulsores de la estructura de las redes planta‐polinizador.
Our results highlight the importance of integrating multiple axes of differentiation such as flowering phenology and floral similarity into our understanding of the drivers of plant–pollinator network structure.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Finding the quantitative trait loci (QTLs) and uncovering the genes controlling early flowering in pumpkin are the basic needs to select appropriate varieties for cultivation. Two QTLs related to ...first female flowering node (FFFN) and four QTLs related to first male flowering node (FMFN) were detected based on high‐density genetic map of pumpkin. Based on annotation information, two candidate genes, flowering locus T‐like protein (FLT) associated with FFFN on chr10 and flowering locus T‐like 2 (FLT2) associated with FMFN on chr11, were identified which were the homologues of flowering time switching gene, flowering Locus T (FT), in different crops. Seven different insertion–deletions (InDels) in promoter regions of FLT and FLT2 were identified by the analysis of wholegenome resequencing data of parental lines. Our results suggested that FLT and FLT2 are candidate genes for controlling FFFN and FMFN traits in pumpkin, respectively. Two insertion–deletion molecular markers were developed to distinguish the lower flowering node F2 individuals. This research will provide the theoretical and practical basis for the selection and cultivation of early flowering pumpkin varieties.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Vernalization is the requirement for exposure to low temperatures to trigger flowering. The best knowledge about the mechanisms of vernalization response has been accumulated for Arabidopsis and ...cereals. In Arabidopsis thaliana, vernalization involves an epigenetic silencing of the MADS-box gene FLOWERING LOCUS C (FLC), which is a flowering repressor. FLC silencing releases the expression of the main flowering inductor FLOWERING LOCUS T (FT), resulting in a floral transition. Remarkably, no FLC homologues have been identified in the vernalization-responsive legumes, and the mechanisms of cold-mediated transition to flowering in these species remain elusive. Nevertheless, legume FT genes have been shown to retain the function of the main vernalization signal integrators. Unlike Arabidopsis, legumes have three subclades of FT genes, which demonstrate distinct patterns of regulation with respect to environmental cues and tissue specificity. This implies complex mechanisms of vernalization signal propagation in the flowering network, that remain largely elusive. Here, for the first time, we summarize the available information on the genetic basis of cold-induced flowering in legumes with a special focus on the role of FT genes.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Many farmers are facing high economic risks if pollinator declines continue or temporal and spatial variation in wild bee communities cause reduced pollination services. Co‐flowering crops might ...compete for pollinators, while they also might facilitate the delivery of pollination services. This rarely studied topic is of particular interest with respect to the foraging decisions of bees from different functional groups and when more sparsely and mass‐flowering crops are in bloom at the same time.
The abundance of honey bees, bumble bees and solitary bees in strawberry fields was quantified with transect walks along a gradient of oilseed rape (OSR) availability (product of OSR land cover and temporally changing OSR flower cover). We established a pollination experiment with pollination treatments (open‐, wind‐ and self‐pollination) to study the effects of insect pollination on strawberry fruit weight and quality.
Changes in OSR availability exhibited contrasting effects on social versus solitary bees in strawberry fields. Bumble bees and honey bees were less abundant in strawberry fields when OSR availability was high, whereas solitary bees were facilitated. With more strawberry flowers, we found more bees in general.
When flowers were open‐pollinated, they resulted in heavier fruits with better commercial grades compared to wind‐ and self‐pollinated flowers. A higher bee abundance enhanced the strawberry fruit weight and quality but depended on flower order and variety.
Synthesis and applications. Sparsely flowering crops may compete with mass‐flowering crops for social bee pollinators, while solitary pollinators in the field might be evenly facilitated. To ensure best fruit weight and quality, it can be beneficial to support bee abundance in the field. While some social and solitary bee species can be managed for pollination services, wild bees, in particular solitary species, should be conserved and promoted for stable crop pollination services in dynamic agricultural landscapes.
Sparsely flowering crops may compete with mass‐flowering crops for social bee pollinators, while solitary pollinators in the field might be evenly facilitated. To ensure best fruit weight and quality, it can be beneficial to support bee abundance in the field. While some social and solitary bee species can be managed for pollination services, wild bees, in particular solitary species, should be conserved and promoted for stable crop pollination services in dynamic agricultural landscapes.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Hybridization is an important evolutionary process that results in increased plant diversity. Flowering Prunus includes popular cherry species that are appreciated worldwide for their flowers. The ...ornamental characteristics were acquired both naturally and through artificially hybridizing species with heterozygous genomes. Therefore, the genome of hybrid flowering Prunus presents important challenges both in plant genomics and evolutionary biology.
We use long reads to sequence and analyze the highly heterozygous genome of wild Prunus yedoensis. The genome assembly covers > 93% of the gene space; annotation identified 41,294 protein-coding genes. Comparative analysis of the genome with 16 accessions of six related taxa shows that 41% of the genes were assigned into the maternal or paternal state. This indicates that wild P. yedoensis is an F1 hybrid originating from a cross between maternal P. pendula f. ascendens and paternal P. jamasakura, and it can be clearly distinguished from its confusing taxon, Yoshino cherry. A focused analysis of the S-locus haplotypes of closely related taxa distributed in a sympatric natural habitat suggests that reduced restriction of inter-specific hybridization due to strong gametophytic self-incompatibility is likely to promote complex hybridization of wild Prunus species and the development of a hybrid swarm.
We report the draft genome assembly of a natural hybrid Prunus species using long-read sequencing and sequence phasing. Based on a comprehensive comparative genome analysis with related taxa, it appears that cross-species hybridization in sympatric habitats is an ongoing process that facilitates the diversification of flowering Prunus.
Marked differences were found between the photoperiodic responses of Bryophyllum daigremontianum and Bryophyllum tubiflorum, both species being classified as long-short-day plants (LSDP). The ...flowering of B. daigremontianum was observed under several photoperiodic conditions, among others under continuous exposure to long day (LD) or after transferring plants from a short-day (SD) to a long-day exposure: both conditions were regarded previously as non-inductive. It is argued that the flowering of B. daigremontianum is conditioned by sufficiently long LD exposure followed by one of two factors: the shortening of the day or the lowering of the temperature. The flowering of B. tubiflorum was observed only under more specific photoperiadic conditions, it seems to be conditioned by several successive changes of the length of the photoperiod.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
