Flowering Patterns Research Articles

DNA methylation is involved in sexual differentiation and sex chromosome evolution in the dioecious plant garden asparagus

DNA methylation is a crucial regulatory mechanism in many biological processes. However, limited studies have dissected the contribution of DNA methylation to sexual differentiation in dioecious plants. In this study, we investigated the variances in methylation and transcriptional patterns of male and female flowers of garden asparagus. Compared with male flowers, female flowers at the same stages showed higher levels of DNA methylation. Both male and female flowers gained DNA methylation globally from the premeiotic to meiotic stages. Detailed analysis revealed that the increased DNA methylation was largely due to increased CHH methylation. Correlation analysis of differentially expressed genes and differentially methylated regions suggested that DNA methylation might not have contributed to the expression variation of the sex-determining genes SOFF and TDF1 but probably played important roles in sexual differentiation and flower development of garden asparagus. The upregulated genes AoMS1, AoLAP3, AoAMS, and AoLAP5 with varied methylated CHH regions might have been involved in sexual differentiation and flower development of garden asparagus. Plant hormone signaling genes and transcription factor genes also participated in sexual differentiation and flower development with potential epigenetic regulation. In addition, the CG and CHG methylation levels in the Y chromosome were notably higher than those in the X chromosome, implying that DNA methylation might have been involved in Y chromosome evolution. These data provide insights into the epigenetic modification of sexual differentiation and flower development and improve our understanding of sex chromosome evolution in garden asparagus.

Temporal organization among pollination systems in a tropical seasonal forest.

Temporal constancy of pollination systems is essential for the maintenance of pollinators through time. Community-level assessment of flowering phenology allows understanding variations across seasons and years and the risks of decoupling flowering and pollinators' activity. We evaluated flowering patterns and temporal diversity of pollination systems in a tropical seasonal forest. We asked whether the temporal organization of flowering times differs among pollination systems; if there is a constancy of pollination systems through the year, since climate and phylogenies constraint flowering time; if there is a prevalent flowering pattern by pollination system, and if the temporal organization of pollination systems by modularity analyses is coherent with grouping by pre-defined seasons. We characterized 10 pollination systems, examined flowering strategies, climate cues and phylogenetic constraints. Pollination by large-to-medium bees dominated (49.2%), followed by diverse insects (22.1%) and flies (14.7%). The remaining systems represented 14% of species. Flowering occurred year-round for most pollination systems, predominating the seasonal flowering strategy. Flowering patterns ranged from aggregated to nested, and random. Climate affected the flowering of most pollination systems, but there was no phylogeny constraint. Modularity grouped pollination systems differently than rainfall seasonality. Contrasting the expectations of reduced temporal constancy, most systems were present year-round, facilitating the exploitation of floral resources by pollinators. Diversity of pollination systems remained constant despite climate seasonality, indicating that several factors influence the optimum flowering time for pollination in seasonally dry vegetations. Global warming may disrupt phenological patterns and the temporal organization of plant communities, a matter for future studies.

Science in your summer garden

Flowers that form fractals Romanesco cauliflower is mesmerizing. Unlike the boring old regular white cauliflower, romanesco’s buds spiral out in a distinctive fractal pattern. But how this pattern comes about is something biologists have been asking for a long time. A recent study suggests that the pattern may be related to the dynamics of how the florets grow ( Science 2021, DOI: 10.1126/science.abg5999 ). Through a combination of computer modeling and genetic experiments, Christophe Godin , a computational scientist at France’s National Institute for Research in Digital Science and Technology and the University of Lyon, and François Parcy , a plant geneticist at the French National Center for Scientific Research and Grenoble Alpes University, mutated the model plant Arabidopsis thaliana to grow in a romanesco-esque flowering pattern. The team found that this change in flowering shape was caused by only one genetic tweak to a cauliflower mutant of the Arabidopsis

Flowering pattern and effective population size in cajuput clonal seed orchard in Yogyakarta, Indonesia

Clonal seed orchard (CSO) is established from superior trees vegetative material to produce the genetically improved seed. The flowering pattern and number of clone in CSO influence seed quality, genetic diversity and the possibility of inbreeding. The study aimed to determine the flowering pattern, identify effective population size and effective clone size in cajuput CSO. This was conducted in cajuput CSO in two sites, i.e. Gunungkidul and Sleman, during peak flowering. The cajuput CSO was established in a randomized complete block design using 30 clones in Sleman and Gunungkidul with five and eight replications, respectively. The flowering number of each individual, number of flowering ramet for each clone and number of capsule retention were recorded. The result showed that the clone performance (i.e., flowering and survival rate) in Sleman was better than in Gunungkidul. Two clones (i.e., number 14 of Provenance Suli, Ambon, and number 30 of Provenance Masarete, Moluccas) in Gunungkidul did not produce flower seed. The effective population size in Gunungkidul (Ne=26.20) is higher than in Sleman (Ne=25). However, the effective clone number in Gunungkidul (Nc=25) is lower than in Sleman (Nc=27). Genetic diversity in both CSOs is high (0.98). Therefore, the proportional mixing of seed collected from both CSO is essential to increase the genetic diversity and the realized genetic gain in deploying seeds for operational planting.

국내산 친환경 면직물에 대한 연구 - 목화재배부터 제품화 -

The purpose of the current study was to find possibility of eco-friendly cultivation, spinning and weaving with domestic seeds of cotton. In the process of cotton cultivation, chemicals such as bleach or softener are not used in the fabrication of yarn or raw paper, and are likely to be seen as unbleached light by completing all processing steps only to boil and catch width. Therefore, it is necessary to develop a design suitable for domestic organic cotton bedding that can satisfy consumer propensity to diversify and personalize consumption patterns. In this study, not only do we exclude pesticides or fertilizers in the cotton cultivation process, but we do not use chemicals such as bleaching or softener deduction in the fabrication process, and we also review the possibility of developing domestic organic cotton fabrics by finishing all processing steps. Physical property came out UHML(in)1.92 was longer than US(1.65), Brazil(1.118), and UI(%)84.9 is high than (82.4), Brazil(81.3) Str.(g/tex)27.3 was low than US(31.4), Brazil(27.5), Mic. was high than US(4.0), Brazil(3.8). Organic tests were gone through noninclusion formaldehyde, phenols, Dioctyltin(DOT), Monobutyltin(MBT), Tributyltin(TBT), Dibutyltin(DBT), organotin compound, riphenyltin(TPhT), insecticide in KOTITI Testing & Research Institute. The yarns been productized in CM30s organic plain twill fabrics of 37.4kg. The fabrics been used infant jeogori, bib, cap and shoes quilting technique by hand, and designed 3 form of patterns quilted pad. The cotton flower designs were developed from going through cultivation of various kind of cotton. The cotton flower patterns were applicated organic cotton fabric bedding cover with the cotton flower pattern for fabric painting coloring and embroidered. Embroidered blankets using cotton flower designs are designed to remove the hassle of re-sewing the single layer whenever the blanket is washed, so that the entire exterior can be washed only by zipping the inner layer with domestic eco-friendly cotton.

Different population size change and migration histories created genetic diversity of three oaks in Tokai region, central Japan.

To understand genetic diversity in focal species, it is important to consider the possibility of speciation with gene flow, especially in species with porous genomes such as oaks. We studied genetic diversity and structure in three oaks, Quercus mongolica var. mongolicoides (QM), Q. mongolica var. crispula (QC) and Q. serrata (QS), growing in the Tokai region, central Japan. QM is semi-endemic to the region while the others are common taxa. We also conducted demographic modeling to infer their population size change and migration histories using an approximate Bayesian computation (ABC) approach. The three taxa showed distinct genetic structures but there was genetic admixture among the taxa, especially between QM and QC. ABC analysis of population size change revealed that the population size of QM was stable during and after the last glacial period, while QC and QS showed population expansion after the last glacial maximum. ABC analysis of population divergence and migration revealed that continuous gene flow between QM and QC after their divergence was supported, while between QM and QS, and between QC and QS, secondary contact after sufficient isolation was supported. These historical migration patterns among the three taxa indicate that QM and QC are currently in the early stage or gray zone of speciation, whereas speciation of the other two taxon pairs is considered to have almost been established. Observed gene flow patterns and strength between QM and QC, and between QM and QS, were explained by both flowering patterns and historical distributions, but those between QC and QS were not.

Elevated CO2 Impacts on Plant–Pollinator Interactions: A Systematic Review and Free Air Carbon Enrichment Field Study

Simple SummaryClimate change is having a profound impact on pollination systems, yet we still do not know to what extent increasing concentrations of carbon dioxide (CO2) will directly affect the interactions between plants and their pollinators. We review all the existing published literature on the effect of elevated CO2 (eCO2) on flowering time, nectar and pollen production and plant–pollinator interactions. We also conduct a field experiment to test the effect of eCO2 on bluebells and their pollinators. We found that few studies have assessed the impact of eCO2 on pollination, and our field data found that bluebells flowered on average 6 days earlier under eCO2 conditions. Hoverflies and bumble bees were the main visitors to bluebell flowers, but insect activity was low early in the flowing period. Although we did not find a difference in the number of visits made by insects to bluebell flowers under eCO2, or the amount of seeds those flowers produced, the change in the timing of flowering could mean that a mismatch could develop between bluebells and their pollinators in the future, which would affect pollination success.The impact of elevated CO2 (eCO2) on plant–pollinator interactions is poorly understood. This study provides the first systematic review of this topic and identifies important knowledge gaps. In addition, we present field data assessing the impact of eCO2 (150 ppm above ambient) on bluebell (Hyacinthoides non-scripta)–pollinator interactions within a mature, deciduous woodland system. Since 1956, only 71 primary papers have investigated eCO2 effects on flowering time, floral traits and pollination, with a mere 3 studies measuring the impact on pollination interactions. Our field experiment documented flowering phenology, flower visitation and seed production, as well as the abundance and phenology of dominant insect pollinators. We show that first and mid-point flowering occurred 6 days earlier under eCO2, but with no change in flowering duration. Syrphid flies and bumble bees were the dominant flower visitors, with peak activity recorded during mid- and late-flowering periods. Whilst no significant difference was recorded in total visitation or seed set between eCO2 and ambient treatments, there were clear patterns of earlier flowering under eCO2 accompanied by lower pollinator activity during this period. This has implications for potential loss of synchrony in pollination systems under future climate scenarios, with associated long-term impacts on abundance and diversity.

High promoter sequence variation in subgroup 6 members of R2R3-MYB genes is involved in different floral anthocyanin color patterns in Lilium spp.

The spatially and temporally distinct expression of R2R3-MYB positive regulators is among the major mechanisms that create various anthocyanin color patterns in many flowers. However, we do not know how these positive regulators have gained different expression profiles. In the Asiatic hybrid lily 'Lollypop' (derived from the crosses of species belonging to Sinomartagon/Daurolirion section), MYB12 and MYB19S regulate the pigmentation at whole tepals and raised tepal spots, respectively. In the Oriental hybrid lily 'Sorbonne' (derived from the crosses of species belonging to the Archelirion section), MYB12 regulates both whole tepal and raised spot pigmentation. The genes have similar amino acid sequences with similar protein functions but exhibit different expression profiles in lily flowers. As promoters are among the most significant factors affecting gene expression profiles, their promoter sequences were determined in this study. The three genes had very different promoter sequences, and putative cis-regulatory elements were not conserved in numbers or order. To further confirm the promoter functions, tobacco plants were transformed with native promoter-driven MYB12 or MYB19S genes of 'Lollypop.' Expression levels of MYB12 were higher in corolla tubes than in lobes, while those of MYB19S were higher in corolla lobes than in tubes. Thus, the diverse promoter functions were likely to be the leading causes of their different expression profiles and generation of unique color patterns. Finally, the history of R2R3-MYB gene establishment during lily evolution was estimated using sequence data.

A population genetics study of three native Mexican woody bamboo species of Guadua (Poaceae: Bambusoideae: Bambuseae: Guaduinae) using nuclear microsatellite markers

Background: Sporadic flowering contributes significantly to genetic diversity and connectivity among populations. Woody bamboos present sporadic or gregarious flowering patterns with long flowering cycles. In this study, we analyze the genetic diversity of three Guadua species distributed along the Gulf of Mexico slope that have different patterns of flowering. 
 Questions: (1) Are the three Guadua species genetically differentiated? (2) Does the vulnerable species G. inermis have low levels of genetic diversity? (3) What is the relative contribution of geographic and environmental factors to the genetic structure of G. inermis ?
 Species studied: Guadua inermis , G. amplexifolia and G. tuxtlensis 
 Study site and dates: During 2014 and 2015, we collected samples of G. inermis in Puebla and southeastern Mexico, G. amplexifolia in Veracruz and Oaxaca, and G. tuxtlensis in southern Veracruz.
 Methods: We successfully amplified five of nine SSR markers, and genotyped a total of 155 samples.
 Results: The three Guadua species were genetically differentiated. For G. inermis , we found high levels of population genetic diversity, which are relatively higher than those of other monocot species. Genetic differentiation was high and three groups were detected: north, central and south. We found a significant association between genetic distances and the maximum temperature of the warmest month, but not with geographic distance. 
 Conclusions: Our study is the first to analyze levels of genetic diversity in Mexican bamboos and confirms their taxonomic identity. G. inermis has a strong genetic structure, even when populations are geographically close.

Transcriptional Cascade in the Regulation of Flowering in the Bamboo Orchid Arundina graminifolia.

Flowering in orchids is the most important horticultural trait regulated by multiple mechanisms. Arundina graminifolia flowers throughout the year unlike other orchids with a narrow flowering span. However, little is known of the genetic regulation of this peculiar flowering pattern. This study identifies a number of transcription factor (TF) families in five stages of flower development and four tissue types through RNA-seq transcriptome. About 700 DEGs were annotated to the transcription factor category and classified into 35 TF families, which were involved in multiple signaling pathways. The most abundant TF family was bHLH, followed by MYB and WRKY. Some important members of the bHLH, WRKY, MYB, TCP, and MADS-box families were found to regulate the flowering genes at transcriptional levels. Particularly, the TFs WRKY34 and ERF12 possibly respond to vernalization and photoperiod signaling, MYB108, RR9, VP1, and bHLH49 regulate hormonal balance, and CCA1 may control the circadian pathway. MADS-box TFs including MADS6, 14, 16, AGL5, and SEP may be important regulators of flowering in A. graminifolia. Therefore, this study provides a theoretical basis for understanding the molecular mechanism of flowering in A. graminifolia.

삼국시대와 통일신라시대의 수막새 연화문양을 활용한 공예문화상품 개발 -3D CAD 장신구 제작을 중심으로-

삼국시대와 통일신라시대의 수막새 연화문양을 활용한 공예문화상품 개발 -3D CAD 장신구 제작을 중심으로-

Distribution and diversity of alternate hosts of Maruca vitrata\xa0Fabricius in three West African countries

The evolution of resistance to the Bacillus thuringiensis (Bt) toxins by insect pests is a major threat to Bt technology. However, the rate of resistance can be slowed with appropriate integrated insect resistance management (IRM) strategies. Surveys were conducted to identify alternate host species for Maruca vitrata (commonly called the legume pod borer or Maruca) that could serve as refuges for Pod-Borer Resistant (PBR) cowpea in three West African countries (Ghana, Nigeria, and Burkina Faso). Survey sites included 25 in northern Ghana, 44 in northern Nigeria, and 52 in north-central and southwestern Burkina Faso. Alternate hosts of Maruca identified from plant species belonging to the Fabaceae family that showed signs of Maruca damage on cowpea tissues were collected and dissected. Larvae that were found during these dissections were reared to adult moths in the laboratory then identified to species. The alternate host plants including species of Crotolaria, Sesbania, Tephrosia, and Vigna were the most frequently encountered among sites and locations. Flowering and podding of these plants overlapped with flowering and podding of the nearby (~200 m) cowpea crop. Abundance of these wild hosts and overlapping flowering patterns with the cowpea crop in most locations have the potential to sustain ample numbers of Bt susceptible Maruca that will mate with possible resistant Maruca and deter resistance development. Further quantitative studies, however, are required from each location to determine if actual Maruca production from alternate hosts is sufficient for a PBR IRM strategy. If verified, this approach would be compatible with the high dose/refuge IRM strategy that includes alternate hosts and non-Bt crops as refuges.

The Process of Promoting the Economic base of the Thai Lanna Textile Handicraft Community in Sukhothai

This research aims to study the potential and develop skills in textile handicrafts of Thai Lanna ethnic group inSukhothai Province. The research process was carried out as follows: 1) study the community context, 2) community-basedknowledge transfer, and 3) the development of textile products using quantitative and qualitative research methods. Researchtools include interviews and questionnaires, collected data from group conversations, and the satisfaction was assessed by aspecific sampling group from key informants from Thai Chanasuek Sub-District Community, Thung Saliam District, Sukhothaiprovince, in the group of 30 people by analyzing descriptive statistics. Research results showed that 1) the Thai Lanna ethniccommunity is a community that immigrated from Lampang Province with the traditions, culture, language, traditions andweaving with a flower pattern which has been the identity of the community and has been produced as costumes, blankets andbags. 2) The knowledge of the weaving production of the community arises from the dynamic exchange of knowledge betweenthe conveyer and the recipient of knowledge in the form of explicit knowledge. Knowledge consolidation and the conversion ofknowledge were applied to enhance the textile products and the economic base of Thai Chanasuek Sub-District Community. 3)Woven fabric pattern design, using the concept of Neem flower to develop the pattern by using cotton brocade technique andprocessing of woven fabrics into clothing with satisfaction in utility, shape and beauty. The average was at a very good level

Recover and They’ll Come: Flower Visiting Bees Benefit from the Continuous of Micro-Environments Set by Regenerating Forest Fragments

Forest habitats are important sources of food and nesting resources for pollinators, primarily in urban areas and landscapes with intense agricultural activity. The forest fragmentation and environmental changes occurring in these green refuges are known to impose survival challenges to pollinating bees, leading to species loss. However, it is not well known how the species of bees that visit flowers are distributed in forest micro-environments. To fill this gap, we sampled flower visiting bees in a continuous forest matrix with micro-environments of two forest types (mature and regenerating forest). We examined how the local environmental changes and climatic conditions affect the composition and uniformity of bee communities in the different micro-environments. Our results indicated that both abundance and richness were similar between forest types studied here, however climatic conditions and plant flowering patterns affect the composition of bees. Thus, our results demonstrated that the continuous micro-environments can favor floral visits and the reintegration of bee communities, and still, that this strategy can be used to minimize the impacts of environmental changes at local scales.

Cotton GhBRC1 regulates branching, flowering, and growth by integrating multiple hormone pathways

Cotton architecture is partly determined by shoot branching and flowering patterns. GhBRC1 was previously identified by RNA-seq analysis of nulliplex-branching and normal-branching cotton. However, the roles of GhBRC1 in cotton remain unclear. In the present study, investigations of nuclear localization and transcriptional activity indicated that GhBRC1 has characteristics typical of transcription factors. Gene expression analysis showed that GhBRC1 was highly expressed in axillary buds but displayed different expression patterns between the two branching types. Overexpression of GhBRC1 in Arabidopsis significantly inhibited the number of branches and promoted flowering. In contrast, silencing GhBRC1 in cotton significantly promoted seedling growth. GhBRC1 was induced by multiple hormones, including strigolactones, which promoted seedling growth and seed germination of Arabidopsis plants overexpressing GhBRC1. Consistent with these findings, RNA-seq analysis of virus-induced gene silencing treated cotton revealed that a large number of genes were differentially expressed between GhBRC1-silenced and control plants, and these genes were significantly enriched in plant hormone signalling pathways. Together, our data indicates that GhBRC1 regulates plant branching and flowering through multiple regulatory pathways, especially those regulating plant hormones, with functions partly differing from those of Arabidopsis BRC1. These results provide insights into the molecular mechanisms controlling plant architecture, which is important for breeding cotton with ideal plant architecture and high yield.

Seasonal and vertical distribution of floral resources and its implications for the conservation of pollinators

The diversity of plant species in blooming throughout the year is a way of ensuring the presence of floral resources, as the spatiotemporal distribution of these resources assists in the movement of pollinators and guarantees local ecosystem services. The aim of this study was to describe the seasonal variations in the vertical distribution of the floral resources that keep the pollinators in Cerrado areas, the savanna region in Central Brazil, a biodiversity hotspot that depends more than 80% on bees for pollination. We studied four cerrado stricto sensu areas and evaluated monthly the flowering phenology, taking into account the number of individuals for each plant species blooming in all vertical strata (arboreal, shrubby, herbaceous, and lianas) and main floral resources (nectar, pollen, and floral oil). We evaluated the annual distribution of flowering plant species and individuals, and the availability of floral resources. We found a seasonal flowering pattern for the whole cerrado stricto sensu, with differences between areas, strata and floral resources types. The floral resources varied idiosyncratically among the strata over time, suggesting complementary blooming patterns throughout the year. The shrubby, herbaceous and liana species were key determinants in the availability of floral resources through the seasons. Our results reinforce the importance of including all the strata in plant surveys, as well as highlight the importance of the vertical stratification in the Cerrado plant formations as a source of floral resources during the time in which there are fewer resources available for pollinators in surrounding forest areas.

Vegetative and reproductive phenology in a tropical grassland–savanna–forest gradient

AbstractQuestionClimate, particularly precipitation, is the primary factor driving tropical plant phenology because of its relevant role in regulating water availability. However, differences in soil physicochemical properties can also drive resource availability, potentially affecting plant phenology, especially under similar environments in terms of rainfall regime. We determined whether the seasonality and synchrony of the vegetative and reproductive phenophases differ along a grassland–savanna–forest gradient under the same climate regime in a Neotropical seasonal ecosystem. We hypothesized that species growing on shallow, nutrient‐impoverished soils have a higher capacity to respond to precipitation pulses than those on rich soils.LocationSerra do Cipó, southeastern Brazil.MethodsWe quantified soil physicochemical properties associated with fertility and water retention of the grassland (campo rupestre), savanna (cerrado) and forest, and determined the phenological strategies of 70 species across the three vegetation types by monitoring vegetative and reproductive phenophases over one year. For each phenophase, in each vegetation type, we evaluated the seasonality and synchrony of phenological patterns. We quantified the phylogenetic signal for phenophases to disentangle the relative roles of historical vs ecological drivers of plant phenology.ResultsSoils from campo rupestre were more nutrient‐ and water‐limited than those of cerrado and forest. Cerrado and forest communities had similar phenological strategies, whereas species from campo rupestre showed strategies that maximize resource acquisition and conservation. In the cerrado and forest, leafing and flowering patterns were seasonal, with leaf flushing and flowering peaking at the onset of the rainy season and leaf senescence in the dry season. Conversely, species from campo rupestre showed continuous leafing and flowering patterns, while fruiting was seasonal. Phenophases did not show a phylogenetic signal.ConclusionsWe demonstrated changes in vegetative and reproductive phenology that are likely associated with variations in soil physicochemical properties. We argue that more severe edaphic filters may have shaped different phenological patterns in campo rupestre.

Flowering Phenology and the Influence of Seasonality in Flower Conspicuousness for Bees.

Flowering patterns are crucial to understand the dynamics of plant reproduction and resource availability for pollinators. Seasonal climate constrains flower and leaf phenology, where leaf and flower colors likely differ between seasons. Color is the main floral trait attracting pollinators; however, seasonal changes in the leaf-background coloration affect the perception of flower color contrasts by pollinators. For a seasonally dry woody cerrado community (Brazilian savanna) mainly pollinated by bees, we verified whether seasonality affects flower color diversity over time and if flower color contrasts of bee-pollinated species differ between seasons due to changes in the leaf-background coloration. For 140 species, we classified flower colors based on human-color vision, and for 99 species, we classified flower colors based on bee-color vision (spectral measurements). We described the community’s flowering pattern according to the flower colors using a unique 11 years phenological database. For the 43 bee-pollinated species in which reflectance data were also available, we compared flower color diversity and contrasts against the background between seasons, considering the background coloration of each season. Flowering was markedly seasonal, peaking at the end of the dry season (September), when the highest diversity of flower colors was observed. Yellow flowers were observed all year round, whereas white flowers were seasonal, peaking during the dry season, and pink flowers predominated in the wet season, peaking in March. Bee-bluegreen flowers peaked between September and October. Flowers from the wet and dry seasons were similarly conspicuous against their corresponding background. Regardless of flowering season, the yellowish background of the dry season promoted higher flower color contrast for all flower species, whereas the greener background of the wet season promoted a higher green contrast. Temporal patterns of flower colors and color contrasts were related to the cerrado seasonality, but also to bee’s activity, visual system, and behavior. Background coloration affected flower contrasts, favoring flower conspicuousness to bees according to the season. Thus, our results provide new insights regarding the temporal patterns of plant–pollinator interactions.

The Diverse Roles of FLOWERING LOCUS C in Annual and Perennial Brassicaceae Species.

Most temperate species require prolonged exposure to winter chilling temperatures to flower in the spring. In the Brassicaceae, the MADS box transcription factor FLOWERING LOCUS C (FLC) is a major regulator of flowering in response to prolonged cold exposure, a process called vernalization. Winter annual Arabidopsis thaliana accessions initiate flowering in the spring due to the stable silencing of FLC by vernalization. The role of FLC has also been explored in perennials within the Brassicaceae family, such as Arabis alpina. The flowering pattern in A. alpina differs from the one in A. thaliana. A. alpina plants initiate flower buds during vernalization but only flower after subsequent exposure to growth-promoting conditions. Here we discuss the role of FLC in annual and perennial Brassicaceae species. We show that, besides its conserved role in flowering, FLC has acquired additional functions that contribute to vegetative and seed traits. PERPETUAL FLOWERING 1 (PEP1), the A. alpina FLC ortholog, contributes to the perennial growth habit. We discuss that PEP1 directly and indirectly, regulates traits such as the duration of the flowering episode, polycarpic growth habit and shoot architecture. We suggest that these additional roles of PEP1 are facilitated by (1) the ability of A. alpina plants to form flower buds during long-term cold exposure, (2) age-related differences between meristems, which enable that not all meristems initiate flowering during cold exposure, and (3) differences between meristems in stable silencing of PEP1 after long-term cold, which ensure that PEP1 expression levels will remain low after vernalization only in meristems that commit to flowering during cold exposure. These features result in spatiotemporal seasonal changes of PEP1 expression during the A. alpina life cycle that contribute to the perennial growth habit. FLC and PEP1 have also been shown to influence the timing of another developmental transition in the plant, seed germination, by influencing seed dormancy and longevity. This suggests that during evolution, FLC and its orthologs adopted both similar and divergent roles to regulate life history traits. Spatiotemporal changes of FLC transcript accumulation drive developmental decisions and contribute to life history evolution.

Morphological and numerical variation patterns of floral organs in two species of Eranthis

There is wide diversity in flower structure and pattern in nature. The number and morphological variation of flower organs in Eranthis of the family Ranunculaceae is high, but the pattern of flower structure variation in this genus is unclear. In this study, the morphological and numerical variation in organs of Eranthis stellata Maxim. and Eranthis lobulata W. T. Wang were observed with stereomicroscopy and scanning electron microscopy, and the patterns of variation were summarized statistically. The results showed the following: (1) The structural patterns of the two species of Eranthis were not stable. There were 232 flower structural patterns among 300 individuals of E. stellata and 55 among 100 individuals of E. lobulata. The number of floral organs in E. lobulata was significantly less than that in E. stellata. (2) The morphological variation in flower organs in Eranthis mainly occurred in petals, especially in the upper lip, pseudonectaries and lower lip, e.g., the number of lobes, and pseudonectaries and inconsistency in the upper lip edge. (3) The coefficient of variation (CV) of flower organs was greater than 20%, with some values close to 40%, which indicates that the number of floral organs of the two species differ substantially, and that the number of floral organs was extremely unstable. The range in stamen number was the largest while that in sepal number was the smallest, and this fluctuation might be caused by the spiral phyllotaxis of floral organs.