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Several closely related Myb-like activator proteins are known to have partially redundant functions within the plant circadian clock, but their specific roles are not well understood. To clarify the function of the REVEILLE 4, REVEILLE 6, and REVEILLE 8 transcriptional activators, we characterized the growth and clock phenotypes of CRISPR-Cas9-generated single, double, and triple rve mutants. We found that these genes act synergistically to regulate flowering time, redundantly to regulate leaf growth, and antagonistically to regulate hypocotyl elongation. We previously reported that increasing intensities of monochromatic blue and red light have opposite effects on the period of triple rve468 mutants. Here, we further examined light quality-specific phenotypes of rve mutants and report that rve468 mutants lack the blue light-specific increase in expression of some circadian clock genes observed in wild type. To investigate the basis of these blue light-specific circadian phenotypes, we examined RVE protein abundances and degradation rates in blue and red light and found no significant differences between these conditions. We next examined genetic interactions between RVE genes and ZEITLUPE and ELONGATED HYPOCOTYL5, two factors with blue light-specific functions in the clock. We found that the RVEs interact additively with both ZEITLUPE and ELONGATED HYPOCOTYL5 to regulate circadian period, which suggests that neither of these factors are required for the blue light-specific differences that we observed. Overall, our results suggest that the RVEs have separable functions in plant growth and circadian regulation and that they are involved in blue light-specific circadian signaling via a novel mechanism.

Abstract: Climate change is altering interactions among plants and pollinators. In alpine ecosystems, where snowmelt timing is a key driver of phenology, earlier snowmelt may generate shifts in plant and pollinator phenology that vary across the landscape, potentially disrupting interactions. Here we ask how experimental advancement of snowmelt timing in a topographically heterogeneous alpine-subalpine landscape impacts flowering, insect pollinator visitation, and pathways connecting key predictors of plant-pollinator interaction. Snowmelt was advanced by an average of 13.5 days in three sites via the application of black sand over snow in manipulated plots, which were paired with control plots. For each forb species, we documented flowering onset and counted flowers throughout the season. We also performed pollinator observations to measure visitation rates. The majority (79.3%) of flower visits were made by dipteran insects. We found that plants flowered earlier in advanced snowmelt plots, with the largest advances in later-flowering species, but flowering duration and visitation rate did not differ between advanced snowmelt and control plots. Using piecewise structural equation models, we assessed the interactive effects of topography on snowmelt timing, flowering phenology, floral abundance, and pollinator visitation. We found that these factors interacted to predict visitation rate in control plots. However, in plots with experimentally advanced snowmelt, none of these predictors explained a significant amount of variation in visitation rate, indicating that different predictors are needed to understand the processes that directly influence pollinator visitation to flowers under future climate conditions. Our findings demonstrate that climate change-induced early snowmelt may fundamentally disrupt the predictive relationships among abiotic and biotic drivers of plant-pollinator interactions in subalpine-alpine environments.

This article examines the role of FIO1, an RNA methyltransferase, in alternative splicing and its impact on flowering regulation in Arabidopsis thaliana. The authors analyze previous studies and find that differences in conclusions may be due to variations in experimental conditions and data analysis methods. They also compare different tools for detecting differential splicing and find that exon-based tools have higher recall rates, while event-based tools have higher precision rates. The study provides insights into the molecular functions of FIO1 and emphasizes the importance of considering experimental conditions and data analysis in research. Additionally, the article explores the potential influence of FIO1 on flowering time but acknowledges the need for further research to fully understand its mechanisms and environmental adaptation. [Extracted from the article]

Summary: Seed vigour, including rapid, uniform germination and robust seedling establishment under various field conditions, is becoming an increasingly essential agronomic trait for achieving high yield in crops. However, little is known about this important seed quality trait. In this study, we performed a genome‐wide association study to identify a key transcription factor ZmRap2.7, which regulates seed vigour through transcriptionally repressing expressions of three ABA signalling genes ZmPYL3, ZmPP2C and ZmABI5 and two phosphatidylethanolamine‐binding genes ZCN9 and ZCN10. In addition, ZCN9 and ZCN10 proteins could interact with ZmPYL3, ZmPP2C and ZmABI5 proteins, and loss‐of‐function of ZmRap2.7 and overexpression of ZCN9 and ZCN10 reduced ABA sensitivity and seed vigour, suggesting a complex regulatory network for regulation of ABA signalling mediated seed vigour. Finally, we showed that four SNPs in ZmRap2.7 coding region influenced its transcriptionally binding activity to the downstream gene promoters. Together with previously identified functional variants within and surrounding ZmRap2.7, we concluded that the distinct allelic variations of ZmRap2.7 were obtained independently during maize domestication and improvement, and responded separately for the diversities of seed vigour, flowering time and brace root development. These results provide novel genes, a new regulatory network and an evolutional mechanism for understanding the molecular mechanism of seed vigour. [ABSTRACT FROM AUTHOR]

Species that repeatedly evolve phenotypic clines across environmental gradients have been highlighted as ideal systems for characterizing the genomic basis of local environmental adaptation. However, few studies have assessed the importance of observed phenotypic clines for local adaptation: conspicuous traits that vary clinally may not necessarily be the most critical in determining local fitness. The present study was designed to fill this gap, using a plant species characterized by repeatedly evolved adaptive phenotypic clines. White clover is naturally polymorphic for its chemical defence cyanogenesis (HCN release with tissue damage); climate‐associated cyanogenesis clines have evolved throughout its native and introduced range worldwide. We performed landscape genomic analyses on 415 wild genotypes from 43 locations spanning much of the North American species range to assess the relative importance of cyanogenesis loci vs. other genomic factors in local climatic adaptation. We find clear evidence of local adaptation, with temperature‐related climatic variables best describing genome‐wide differentiation between sampling locations. The same climatic variables are also strongly correlated with cyanogenesis frequencies and gene copy number variations (CNVs) at cyanogenesis loci. However, landscape genomic analyses indicate no significant contribution of cyanogenesis loci to local adaptation. Instead, several genomic regions containing promising candidate genes for plant response to seasonal cues are identified — some of which are shared with previously identified QTLs for locally adaptive fitness traits in North American white clover. Our findings suggest that local adaptation in white clover is likely determined primarily by genes controlling the timing of growth and flowering in response to local seasonal cues. More generally, this work suggests that caution is warranted when considering the importance of conspicuous phenotypic clines as primary determinants of local adaptation. [ABSTRACT FROM AUTHOR]

Ornithopus sativus Brot. (French serradella) is a forage legume that is well adapted to acidic coarse textured soils (sands) which are characterized by poor nutrition and an inability to retain water. During the process of domestication of O. sativus, there was an unintentional loss of seed physical dormancy (PY) thus compromising its self‐regeneration after a cropping interval. Through mass screening of seed, we identified for the first time that heritable sources of PY exist in three populations of O. sativus. This rare genetic material was then incorporated into suitable genetic backgrounds of differing maturity through targeted hybridization. We demonstrated that the heritability of PY was dominant in the population of 97ZAF5sat but inconsistently recessive in the population of cv. Emena. Flowering time was variable in each source population, with a large variation in time to emergence of first flowers (95–175 days). Selection for early flowering maturity was heritable and stable. F6 generations selected for PY in different maturity classes were then evaluated in situ to establish whether PY would allow a proportion of seeds to survive in the soil through consecutive seasons exposed to a Mediterranean climate. The breeding lines FHS3, 7 and 23 remained dormant, thus viable, in the soil for up to 3 years, indicating the likelihood that O. sativus with PY could survive and persist in a ley farming system. The de‐domestication program in O. sativus has resulted in commercially successful cultivars (most recently cv. Fran2o) suited to sustainable dryland agriculture in a Mediterranean climate. [ABSTRACT FROM AUTHOR]

To better understand the implications of climate change, the combined responses of olive trees to irrigation amount and warming need to be examined. Thus, the objective was to evaluate the effects of moderate deficit irrigation and warming during late winter and spring on vegetative growth and biomass, full bloom timing and intensity, and yield components in young olive trees. Two three month-long experiments were conducted using open top chambers with four treatment combinations: 100% irrigation with a control temperature; 100% irrigation with 4 °C warming; 50% irrigation with a control temperature; and 50% irrigation with 4 °C warming. The trees were potted two-year-old, cv. Arbequina trees in the 2018 experiment and three-year-old, cv. Coratina trees in the 2019 experiment. Flowering was low in the young cv. Arbequina trees in 2018, but it was much greater in the older cv. Coratina trees in 2019. Overall, lower flowering intensity and fruit set or more parthenocarpic fruit contributed to less viable fruit number with warming. These reproductive variables were less affected by deficit irrigation. In contrast, shoot growth and vegetative biomass were decreased by deficit irrigation in cv. Arbequina (2018) when fruit number was low in all trees with less response due to warming. In cv. Coratina (2019), the lower fruit number in warmed compared to control trees contributed to greater individual fruit weight at the end of the experimental period, and few significant effects of either deficit irrigation or warming on shoot growth were observed. Fruit yield was greater in the well-irrigated, temperature control than in the other treatment combinations in cv. Arbequina, while warming reduced fruit yield in cv. Coratina. From a production perspective, it does not appear that many early reproductive responses to warming can be easily counteracted by adjusting irrigation. Further studies with more mature trees and cultivars over several growing seasons are recommended. [ABSTRACT FROM AUTHOR]

Background and Aims Some plants germinate their seeds enclosed by a pericarp, whereas others lack the outer packaging. As a maternal tissue, the pericarp might impart seeds with different germination strategies. Plants in a community with different flowering times might separately disperse and germinate their seeds; therefore, flowering time can be considered as one manifestation of maternal effects on the offspring. The mass of the seed is another important factor influencing germination and represents the intrinsic resource of the seed that supports germination. Using seeds from a species-rich alpine meadow located in the Hengduan Mountains of China, a global biodiversity hotspot, we aimed to illustrate whether and how the type of seed (with or without a pericarp) modulates the interaction of flowering time and seed mass with germination. Methods Seeds were germinated in generally favourable conditions, and the speed of germination [estimated by mean germination time (MGT)] was calculated. We quantified the maternal conditions by separation of flowering time for 67 species in the meadow, of which 31 produced seeds with pericarps and 36 yielded seeds without pericarps. We also weighed 100 seeds of each species to assess their mass. Key Results The MGT varied between the two types of seeds. For seeds with pericarps, MGT was associated with flowering time but not with seed mass. Plants with earlier flowering times in the meadow exhibited more rapid seed germination. For seeds without a pericarp, the MGT depended on seed mass, with smaller seeds germinating more rapidly than larger seeds. Conclusions The distinct responses of germination to flowering time and seed mass observed in seeds with and without a pericarp suggest that germination strategies might be mother-reliant for seeds protected by pericarps but self-reliant for those without such protection. This new finding improves our understanding of seed germination by integrating ecologically mediated maternal conditions and inherent genetic properties. [ABSTRACT FROM AUTHOR]

As climate change continues and the frequency and intensity of droughts become more prevalent in some regions, plant populations are facing greater ecological pressures. The objective of this study was to observe the response of a rare plant species to an extreme drought event associated with climate change. To study this response, we collected seeds from three populations of Collinsia multicolor (San Francisco collinsia, Plantaginaceae) found in central California both before and after the state's historic 2012-2016 drought. We conducted a greenhouse study to examine contemporary evolution between the collection years, and included a drought treatment to study plasticity. We measured three traits that indicate life history, morphological, and physiological responses to drought, including flowering time, stomatal density, and chlorophyll fluorescence. In the two coastal populations, where interannual moisture variation is greatest, we observed evolution only in stomatal density, while we observed plasticity in all measured traits. In contrast, the driest inland population showed no response to the drought or to the watering treatments, which is consistent with other studies that have found less response to drought in pre-adapted populations. Overall, our results suggest that plasticity is favored in variable environments. However, they also highlight that the pace of evolution may be insufficient to respond to current environmental change. [ABSTRACT FROM AUTHOR]

Enhalus acoroides (L.f.) Royle is a large and important foundation seagrass species in the tropical Indo-Pacific. The northern marginal populations in China have been declining over the last decades. The reproductive phenology and fruit set of this dioecious seagrass were investigated from June 2017 to February 2018 in two areas in Li'an lagoon, Hainan Island, China. We found that E. acoroides flowered year-round. However, the flowering intensity varied among seasons and was highest in the summer and lowest in the winter. The shoot sex ratio was male-biased, and the pollen-ovule ratio was approximately 104: 1, based on the sex ratio and the number of male florets per inflorescence. Female and male plants flowered at the same time in this population. Despite the high reproductive investment in terms of flower formation observed throughout the year, the abundance of the mature fruits was low, possibly due to physical disturbance and cover by epiphyte and algae. This study provides insight into the reproductive ecology of E. acoroides, which will be useful for the future conservation of this threatened seagrass. [ABSTRACT FROM AUTHOR]

The article discusses the role of PHO1, a protein involved in phosphate translocation, in regulating flowering time in plants. The study found that mutations in the PHO1 gene resulted in delayed flowering in Arabidopsis plants. The authors also discovered that PHO1 interacts with the jasmonic acid (JA) signaling pathway, which is known to play a role in plant reproduction. Additionally, the study identified other genes and hormonal pathways that may be involved in the regulation of flowering time. The findings contribute to our understanding of the molecular mechanisms governing flowering time regulation in plants. [Extracted from the article]

Phosphorus nutrition has been known for a long time to influence floral transition in plants, but the underlying mechanism is unclear. Arabidopsis phosphate transporter PHOSPHATE1 (PHO1) plays a critical role in phosphate translocation from roots to shoots, but whether and how it regulates floral transition is unknown. Here, we show that knockout mutation of PHO1 delays flowering under both long- and short-day conditions. The late flowering of pho1 mutants can be partially rescued by Pi supplementation in rosettes or shoot apices. Grafting assay indicates that the late flowering of pho1 mutants is a result of impaired phosphate translocation from roots to shoots. Knockout mutation of SPX1 and SPX2 , two negative regulators of the phosphate starvation response, partially rescues the late flowering of pho1 mutants. PHO1 is epistatic to PHO2, a negative regulator of PHO1, in flowering time regulation. Loss of PHO1 represses the expression of some floral activators, including FT encoding florigen, and induces the expression of some floral repressors in shoots. Genetic analyses indicate that at least jasmonic acid signaling is partially responsible for the late flowering of pho1 mutants. In addition, we find that rice PHO1;2 , the homolog of PHO1 , plays a similar role in floral transition. These results suggest that PHO1 integrates phosphorus nutrition and flowering time, and could be used as a potential target in modulating phosphorus nutrition-mediated flowering time in plants. [ABSTRACT FROM AUTHOR]

The SET domain genes (SDGs) are significant contributors to various aspects of plant growth and development, mainly includes flowering, pollen development, root growth, regulation of the biological clock and branching patterns. To clarify the biological functions of the chrysanthemum SDG family, the SDG family members of four chrysanthemum cultivars and three related wild species were identified; their physical and chemical properties, protein domains and conserved motifs were predicted and analyzed. The results showed that 59, 67, 67, 102, 106, 114, and 123 SDGs were identified from Chrysanthemum nankingense, Chrysanthemum lavandulifolium, Chrysanthemum seticuspe, Chrysanthemum × morifolium cv. 'Hechengxinghuo', 'Zhongshanzigui', 'Quanxiangshuichang' and 'Jinbeidahong', respectively. The SDGs were divided into 5–7 subfamilies by cluster analysis; different conserved motifs were observed in particular families. The SDGs of C. lavandulifolium and C. seticuspe were distributed unevenly on 9 chromosomes. SDG promoters of different species include growth and development, photo-response, stress response and hormone responsive elements, among them, the cis-acting elements related to MeJA response had the largest proportion. The expression of chrysanthemum SDG genes was observed for most variable selected genes which has close association with important Arabidopsis thaliana genes related to flowering regulation. The qPCR results showed that the expression trend of SDG genes varied in different tissues at different growth stages with high expression in the flowering period. The ClSDG29 showed higher expression in the flower and bud tissues, which indicate that ClSDG29 might be associated with flowering regulation in chrysanthemum. In summary, the results of this study can provide a basis for subsequent research on chrysanthemum flowering time regulation. [ABSTRACT FROM AUTHOR]

The optimal timing of transition from vegetative to floral reproductive phase is critical for plant productivity and agricultural yields. Light plays a decisive role in regulating this transition. The B‐box (BBX) family of transcription factors regulates several light‐mediated developmental processes in plants, including flowering. Here, we identify a previously uncharacterized group II BBX family member, BBX13/COL15, as a negative regulator of flowering under long‐day conditions. BBX13 is primarily expressed in the leaf vasculature, buds, and flowers, showing a similar spatial expression pattern to the major flowering time regulators CO and FT. bbx13 mutants flower early, while BBX13‐overexpressors exhibit delayed flowering under long days. Genetic analyses showed that BBX13 acts upstream to CO and FT and negatively regulates their expression. BBX13 physically interacts with CO and inhibits the CO‐mediated transcriptional activation of FT. In addition, BBX13 directly binds to the CORE2 motif on the FT promoter, where CO also binds. Chromatin immunoprecipitation data indicates that BBX13 reduces the in vivo binding of CO on the FT promoter. Through luciferase assay, we found that BBX13 inhibits the CO‐mediated transcriptional activation of FT. Together, these findings suggest that BBX13/COL15 represses flowering in Arabidopsis by attenuating the binding of CO on the FT promoter. [ABSTRACT FROM AUTHOR]

Background: PSEUDO RESPONSE REGULATOR (PRR) genes are essential components of circadian clock, playing vital roles in multiple processes including plant growth, flowering and stress response. Nonetheless, little is known about the evolution and function of PRR family in Rosaceae species. Results: In this study, a total of 43 PRR genes in seven Rosaceae species were identified through comprehensive analysis. The evolutionary relationships were analyzed with phylogenetic tree, duplication events and synteny. PRR genes were classified into three groups (PRR1, PRR5/9, PRR3/7). The expansion of PRR family was mainly derived from dispersed and whole-genome duplication events. Purifying selection was the major force for PRR family evolution. Synteny analysis indicated the existence of multiple orthologous PRR gene pairs between pear and other Rosaceae species. Moreover, the conserved motifs of eight PbPRR proteins supported the phylogenetic relationship. PRR genes showed diverse expression pattern in various tissues of pear (Pyrus bretschneideri). Transcript analysis under 12-h light/ dark cycle and constant light conditions revealed that PRR genes exhibited distinct rhythmic oscillations in pear. PbPRR59a and PbPRR59b highly homologous to AtPRR5 and AtPRR9 were cloned for further functional verification. PbPRR59a and PbPRR59b proteins were localized in the nucleus. The ectopic overexpression of PbPRR59a and PbPRR59b significantly delayed flowering in Arabidopsis transgenic plants by repress the expression of AtGI, AtCO and AtFT under long-day conditions. Conclusions: These results provide information for exploring the evolution of PRR genes in plants, and contribute to the subsequent functional studies of PRR genes in pear and other Rosaceae species. [ABSTRACT FROM AUTHOR]

Bamboo flowering occurs over a long cycle, yet the precise mechanisms and consequences of this phenomenon remain unknown. Although several studies have investigated the dynamics of forest communities post‐flowering, the effects of flowering on the material cycle remain unclear. Recent reports have documented the first flowering of Phyllostachys nigra var. henonis in 120 years across several regions of Japan. P. nigra var. henonis flowers exhibit higher nitrogen concentrations compared to their leaves, suggesting potentially different decomposition patterns upon reaching the forest floor and subsequent contributions to the nitrogen cycle. Based on this observation, we conducted decomposition experiments using litter bags to investigate the dynamics of organic matter and nitrogen. After 1 year, litter bags containing both leaves and flowers were retrieved. The remaining mass of flower and leaf litter was 38% and 60%, respectively. On the other hand, the nitrogen remaining in flower and leaf litter was 54.9% and 98.2%, respectively. Net nitrogen release from the flower litter was estimated to be 36 kg/ha/year in the study site. The potential maximum nitrogen released from flower litter decomposition in a high‐density ramet stand was estimated to be 221 kg/ha/year. The results of this study suggest that the nitrogen addition through mass flowering of P. nigra var. henonis would have a significant impact on the nitrogen cycle of the ecosystem. [ABSTRACT FROM AUTHOR]

Summary: Flowering is a vital agronomic trait that determines the economic value of most ornamental plants. The flowering time of rose (Rosa spp.) is photoperiod insensitive and is thought to be tightly controlled by light intensity, although the detailed molecular mechanism remains unclear.Here, we showed that rose plants flower later under low‐light (LL) intensity than under high‐light (HL) intensity, which is mainly related to the stability of PHYTOCHROME‐INTERACTING FACTORs (RcPIFs) mediated by OPEN STOMATA 1‐Like (RcOST1L) under different light intensity regimes.We determined that HL conditions trigger the rapid phosphorylation of RcPIFs before their degradation. A yeast two‐hybrid screen identified the kinase RcOST1L as interacting with RcPIF4. Moreover, RcOST1L positively regulated rose flowering and directly phosphorylated RcPIF4 on serine 198 to promote its degradation under HL conditions. Additionally, phytochrome B (RcphyB) enhanced RcOST1L‐mediated phosphorylation of RcPIF4 via interacting with the active phyB‐binding motif. RcphyB was activated upon HL and recruited RcOST1L to facilitate its nuclear accumulation, in turn leading to decreased stability of RcPIF4 and flowering acceleration.Our findings illustrate how RcPIF abundance safeguards proper rose flowering under different light intensities, thus uncovering the essential role of RcOST1L in the RcphyB–RcPIF4 module in flowering. [ABSTRACT FROM AUTHOR]

Accurate prediction of flowering times is essential for efficient orchard management for kiwifruit, facilitating timely pest and disease control and pollination interventions. In this study, we developed a predictive model for flowering time using weather data and observations of budbreak dynamics for the 'Hayward' and 'Zesy002' kiwifruit. We used historic data of untreated plants collected from 32 previous studies conducted between 2007 and 2022 and analyzed budbreak and flowering timing alongside cumulative heat sum (growing degree days, GDDs), chilling unit (CU) accumulation, and other environmental variables using weather data from the weather stations nearest to the study orchards. We trained/parameterized the model with data from 2007 to 2019, and then evaluated the model's efficacy using testing data from 2020 to 2022. Regression models identified a hierarchical structure with the accumulation of GDDs at the start of budbreak, one of the key predictors of flowering time. The findings suggest that integrating climatic data with phenological events such as budbreak can enhance the predictability of flowering in kiwifruit vines, offering a valuable tool for kiwifruit orchard management. [ABSTRACT FROM AUTHOR]

The heading date, a critical trait influencing the rice yield and quality, has always been a hot topic in breeding research. Appropriately delaying the flowering time of excellent northern rice varieties is of great significance for improving yields and enhancing regional adaptability during the process for introducing varieties from north to south. In this study, genes influencing the heading date were identified through genome-wide association studies (GWAS). Using KenDao 12 (K12), an excellent cultivar from northern China, as the material, the specific flowering activator, OsMADS50, was edited using the genome-editing method to regulate the heading date to adapt to the southern planting environment. The results indicated that the osmads50 mutant line of K12 flowered about a week later, with a slight increase in the yield and good adaptability in the southern region in China. Additionally, the expressions of key flowering regulatory genes, such as Hd1, Ghd7, Ehd1, Hd3a, and RFT1, were reduced in the mutant plants, corroborating the delayed flowering phenotype. Yield trait analysis revealed that the primary factor for improved yield was an increase in the number of effective tillers, although there is potential for further enhancements in the seed-setting rate and grain plumpness. Furthermore, there were significant increases in the length-to-width ratio of the rice grains, fat content, and seed transparency, all contributing to an overall improvement in the rice quality. In summary, this study successfully obtained a rice variety with a delayed growth period through OsMADS50 gene editing, effectively implementing the strategy for adapting northern rice varieties to southern climates. This achievement significantly supports efforts to enhance the rice yield and quality as well as to optimize production management practices. [ABSTRACT FROM AUTHOR]

Flowering is critical to the success of plant propagation. The MYB family transcription factor CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) is an essential component of the core loop of the circadian clock and plays a crucial role in regulating plant flowering time. In this study, we found that photoperiod affects the expression pattern and expression level of BcCCA1, which is delayed flowering time under short-day conditions in Pak-choi [Brassica campestris (syn. Brassica rapa) ssp. chinensis]. We detected overexpression and silencing of BcCCA1 in Pak-choi, resulting in delayed and promoted flowering time, respectively. Furthermore, we also discovered that FLOWERING LOCUS C (BcFLC) and SUPPRESSOR OF CONSTANS1 (BcSOC1) were expressed significantly differently in BcCCA1 overexpression and silencing plants compared with control plants. Therefore, we further investigated the interaction relationship between BcCCA1, BcFLC, and BcSOC1, and the results showed that BcCCA1 and BcFLC as a complex interacted with each other. Moreover, both BcCCA1 and BcFLC can directly bind to the promoter of BcSOC1 and repress its transcription, and BcCCA1 can form a complex with BcFLC to enhance the transcriptional inhibition of BcSOC1 by BcFLC. This study reveals a new mechanism by which the circadian clock regulates flowering time. [ABSTRACT FROM AUTHOR]

Flowering in plants is pivotal for initiating and advancing reproductive processes, impacting regional adaptation and crop yield. Despite numerous cloned and identified flowering time genes, research in cotton remains sparse. This study identified GhSWEET42 as a key determinant of the flowering time in cotton, demonstrating that its heterologous expression in Arabidopsis accelerated flowering under LD conditions compared to WT. Transgenic plants exhibited upregulated expression of the flowering inducers AtFT, AtSOC1, AtGI, and AtFKF1, alongside downregulated expression of the repressors AtTSF, AtFLC, and AtRGL2, correlating with the earlier flowering phenotype. GhSWEET42 showed a constitutive expression pattern, with elevated levels in the leaves, petals, and flower buds, and was notably higher in early-maturing cotton varieties. Subcellular localization assays confirmed GhSWEET42's presence on the cell membrane. Transcriptome analysis between WT and GhSWEET42-overexpressing Arabidopsis plants revealed 2393 differentially expressed genes (DEGs), spanning 221 biological processes, 93 molecular functions, and 37 cellular components according to Gene Ontology (GO) enrichment analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis categorized the DEGs into metabolism and environmental information processing. These findings enhance the understanding of GhSWEET42's function and provide a foundation for elucidating the molecular mechanisms governing flowering time regulation in cotton. [ABSTRACT FROM AUTHOR]

Plants flower in response to environmental signals. These signals change the shape and developmental identity of the shoot apical meristem (SAM), causing it to form flowers and inflorescences. We show that the increases in SAM width and height during floral transition correlate with changes in size of the central zone (CZ), defined by CLAVATA3 expression, and involve a transient increase in the height of the organizing center (OC), defined by WUSCHEL expression. The APETALA2 (AP2) transcription factor is required for the rapid increases in SAM height and width, by maintaining the width of the OC and increasing the height and width of the CZ. AP2 expression is repressed in the SAM at the end of floral transition, and extending the duration of its expression increases SAM width. Transcriptional repression by SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) represents one of the mechanisms reducing AP2 expression during floral transition. Moreover, AP2 represses SOC1 transcription, and we find that reciprocal repression of SOC1 and AP2 contributes to synchronizing precise changes in meristem shape with floral transition. Bertran Garcia de Olalla, Cerise and colleagues discovered that the transcription factor APETALA2 has a dual role at the shoot tip of Arabidopsis, where it both mediates changes in the timing of flowering and in the morphology of the shoot apex. [ABSTRACT FROM AUTHOR]

Members of the genus Hemerocallis have significant value as ornamental, edible, and medicinal plants, particularly in China, where they have been utilized for thousands of years as both a vegetable and Traditional Chinese Medicine. Hemerocallis species exhibit strict control over flowering time, with individuals flowering either diurnally or nocturnally. However, our understanding of the evolutionary history of this genus, especially concerning important horticultural traits, remains limited. In this study, sequencing and assembly efforts were conducted on 73 samples within the Hemerocallis genus. All accessions were classified into two distinct groups based on their diurnal (daylilies) or nocturnal (nightlilies) flowering habits. Comparative analysis of the chloroplast genomes from these two groups identified fifteen variant hotspot regions, including fourteen SNPs and one deletion, which hold promise for the development of molecular markers for interspecific identification. Phylogenetic trees, generated through both maximum-likelihood and Bayesian inference methods using 76 shared protein-coding sequences, revealed that diurnal flowering evolved prior to nocturnal flowering. The divergence between the two groups is estimated to have occurred approximately 0.82 MYA (95% CI: 0.35-1.45 MYA). The ancestral state of Hemerocallis is hypothesized to have featured diurnal flowering with orange yellow petals. This study marks the first reconstruction of the evolutionary history and ancestral state of the genus Hemerocallis. The findings contribute significantly to our understanding of the adaptation and speciation history within the genus. [ABSTRACT FROM AUTHOR]

Light-emitting diodes have been beneficial for plant growth, especially for microgreens in countries with low radiation, greenhouses, and chambers. However, information about how plants respond to additional light-emitting diode lighting after 12 hours of sunlight exposure in tropical areas is limited. This study examines the effects of long-duration light-emitting diodes on mustard greens in Kien Giang province, Vietnam (105°14’33.21” E; 9°91’41.13” N). The trials were conducted in the greenhouse for two growing seasons with a completely randomized design, including 0, 2, 4, and 6 hours of assembled light-emitting diodes lighting and 4 hours of commercial light-emitting diodes lighting after 6 pm, with three replications. Results showed that weather factors in season 2 favorably influenced mustard’s growth. At 4 hours of lighting, commercial light-emitting diodes showed a higher chlorophyll index, flowering time, flowering rate, leaf number, and absolute growth rate of leaf number but less leaf and fresh shoot weight than assembled light-emitting diodes. Four hours of assembled light-emitting diodes positively affected most mustard growth, while 6 hours of assembled light-emitting diodes were superior for flowering aspects. Adding 4 hours of light-emitting diodes could increase leafy yield and shorten the harvesting time of mustard greens grown in greenhouses under tropical conditions. [ABSTRACT FROM AUTHOR]

Monocarpic senescence, characterized by whole-plant senescence following a single flowering phase, is widespread in seed plants, particularly in crops, determining seed harvest time and quality. However, how external and internal signals are systemically integrated into monocarpic senescence remains largely unknown. Here, we report that the Arabidopsis thaliana transcription factor WRKY1 plays essential roles in multiple key steps of monocarpic senescence. WRKY1 expression is induced by age, salicylic acid (SA), and nitrogen (N) deficiency. Flowering and leaf senescence are accelerated in the WRKY1 overexpression lines but are delayed in the wrky1 mutants. The combined DNA affinity purification sequencing and RNA sequencing analyses uncover the direct target genes of WRKY1. Further studies show that WRKY1 coordinately regulates three processes in monocarpic senescence: (1) suppressing FLOWERING LOCUS C gene expression to initiate flowering, (2) inducing SA biosynthesis genes to promote leaf senescence, and (3) activating the N assimilation and transport genes to trigger N remobilization. In summary, our study reveals how one stress-responsive transcription factor, WRKY1, integrates flowering, leaf senescence, and N remobilization processes into monocarpic senescence, providing important insights into plant lifetime regulation. This study reveals that the stress-inducible WRKY1 transcription factor serves as a versatile regulator that integrates multiple key processes of monocarpic senescence in Arabidopsis. WRKY1 plays crucial roles in promoting flowering through direct repression of FLC expression, accelerating leaf senescence via activation of SA biosynthesis genes, and facilitating efficient N remobilization via activation of N assimilation and transport genes. [ABSTRACT FROM AUTHOR]

Background: The SET domain group (SDG) genes encode histone lysine methyltransferases, which regulate gene transcription by altering chromatin structure and play pivotal roles in plant flowering determination. However, few studies have investigated their role in the regulation of flowering in upland cotton. Results: A total of 86 SDG genes were identified through genome-wide analysis in upland cotton (Gossypium hirsutum). These genes were unevenly distributed across 25 chromosomes. Cluster analysis revealed that the 86 GhSDGs were divided into seven main branches. RNA-seq data and qRT‒PCR analysis revealed that lysine methyltransferase 3 (KMT3) genes were expressed at high levels in stamens, pistils and other floral organs. Using virus-induced gene silencing (VIGS), functional characterization of GhKMT3;1a and GhKMT3;2a revealed that, compared with those of the controls, the GhKMT3;1a- and GhKMT3;2a-silenced plants exhibited later budding and flowering and lower plant heightwere shorter. In addition, the expression of flowering-related genes (GhAP1, GhSOC1 and GhFT) significantly decreased and the expression level of GhSVP significantly increased in the GhKMT3;1a- and GhKMT3;2a-silenced plants compared with the control plants. Conclusion: A total of 86 SDG genes were identified in upland cotton, among which GhKMT3;1a and GhKMT3;2a might regulate flowering by affecting the expression of GhAP1, GhSOC1, GhFT and GhSVP. These findings will provide genetic resources for advanced molecular breeding in the future. [ABSTRACT FROM AUTHOR]

Flowering, the transition from the vegetative to the reproductive stage, is vital for reproductive success, affecting forage quality, the yield of aboveground biomass, and seed production in alfalfa. To explore the transcriptomic profile of alfalfa flowering transition, we compared gene expression between shoot apices (SAs) at the vegetative stage and flower buds (FBs) at the reproductive stage by mRNA sequencing. A total of 3,409 DEGs were identified, and based on gene ontology (GO), 42.53% of the most enriched 15 processes were associated with plant reproduction, including growth phase transition and floral organ development. For the former category, 79.1% of DEGs showed higher expression levels in SA than FB, suggesting they were sequentially turned on and off at the two test stages. For the DEGs encoding the components of circadian rhythm, sugar metabolism, phytohormone signaling, and floral organ identity genes, 60.71% showed higher abundance in FB than SA. Among them, MsAP1, an APETALA1 (AP1) homolog of Arabidopsis thaliana, showed high expression in flower buds and co-expressed with genes related to flower organ development. Moreover, ectopic expression of MsAP1 in Arabidopsis resulted in dwarfism and early flowering under long-day conditions. The MsAP1-overexpression plant displayed morphological abnormalities including fused whorls, enlarged pistils, determinate inflorescence, and small pods. In addition, MsAP1 is localized in the nucleus and exhibits significant transcriptional activity. These findings revealed a transcriptional regulation network of alfalfa transition from juvenile phase to flowering and provided genetic evidence of the dual role of MsAP1 in flowering and floral organ development. [ABSTRACT FROM AUTHOR]

Phytoplasmic SAP11 effectors alter host plant architecture and flowering time. However, the exact mechanisms have yet to be elucidated. Two SAP11‐like effectors, SJP1 and SJP2, from 'Candidatus Phytoplasma ziziphi' induce shoot branching proliferation. Here, the transcription factor ZjTCP7 was identified as a central target of these two effectors to regulate floral transition and shoot branching. Ectopic expression of ZjTCP7 resulted in enhanced bolting and earlier flowering than did the control. Interaction and expression assays demonstrated that ZjTCP7 interacted with the ZjFT‐ZjFD module, thereby enhancing the ability of these genes to directly bind to the ZjAP1 promoter. The effectors SJP1 and SJP2 unravelled the florigen activation complex by specifically destabilising ZjTCP7 and ZjFD to delay floral initiation. Moreover, the shoot branching of the ZjTCP7‐SRDX transgenic Arabidopsis lines were comparable to those of the SJP1/2 lines, suggesting the involvement of ZjTCP7 in the regulation of shoot branching. ZjTCP7 interacted with the branching repressor ZjBRC1 to enhance suppression of the auxin efflux carrier ZjPIN3 expression. ZjTCP7 also directly bound to and upregulated the auxin biosynthesis gene ZjYUCCA2, thereby promoting auxin accumulation. Our findings confirm that ZjTCP7 serves as a bifunctional regulator destabilised by the effectors SJP1 and SJP2 to modulate plant development. Summary statement: Efectors SJP1 and SJP2 interact with and destabilise the bifunctional regulator ZjTCP7 to modulate flowering‐related ZjFT‐ZjFD pathway and branching signalling controlled by ZjBRC1 in jujube, suggesting a novel regulatory mechanism mediated by JWB phytoplasmas to modulate host plant development. [ABSTRACT FROM AUTHOR]

Summary: Soybean is a typical short‐day crop, and most commercial soybean cultivars are restricted to a relatively narrow range of latitudes due to photoperiod sensitivity. Photoperiod sensitivity hinders the utilization of soybean germplasms across geographical regions. When grown in temperate regions, tropical soybean responds to prolonged day length by increasing the vegetative growth phase and delaying flowering and maturity, which often pushes the harvest window past the first frost date. In this study, we used CRISPR/LbCas12a to edit a North American subtropical soybean cultivar named 06KG218440 that belongs to maturity group 5.5. By designing one gRNA to edit the nuclear localization signal (NLS) regions of both E1 and E1Lb, we created a series of new germplasms with shortened flowering time and time to maturity and determined their favourable latitudinal zone for cultivation. The novel partial function alleles successfully achieve yield and early maturity trade‐offs and exhibit good agronomic traits and high yields in temperate regions. This work offers a straightforward editing strategy to modify subtropical and tropical soybean cultivars for temperate growing regions, a strategy that could be used to enrich genetic diversity in temperate breeding programmes and facilitate the introduction of important crop traits such as disease tolerance or high yield. [ABSTRACT FROM AUTHOR]

Physic nut (Jatropha curcas L.) has attracted extensive attention because of its fast growth, easy reproduction, tolerance to barren conditions, and high oil content of seeds. SWEET (Sugar Will Eventually be Exported Transporter) family genes contribute to regulating the distribution of carbohydrates in plants and have great potential in improving yield and stress tolerance. In this study, we performed a functional analysis of the homology of these genes from physic nut, JcSWEET12 and JcSWEET17a. Subcellular localization indicated that the JcSWEET12 protein is localized on the plasma membrane and the JcSWEET17a protein on the vacuolar membrane. The overexpression of JcSWEET12 (OE12) and JcSWEET17a (OE17a) in Arabidopsis leads to late and early flowering, respectively, compared to the wild-type plants. The transgenic OE12 seedlings, but not OE17a, exhibit increased salt tolerance. In addition, OE12 plants attain greater plant height and greater shoot dry weight than the wild-type plants at maturity. Together, our results indicate that JcSWEET12 and JcSWEET17a play different roles in the regulation of flowering time and salt stress response, providing a novel genetic resource for future improvement in physic nut and other plants. [ABSTRACT FROM AUTHOR]

Flowering time and maturity are crucial agronomic traits that affect the regional adaptability of soybean plants. The development of soybean cultivars with early maturity adapted to longer days and colder climates of high latitudes is very important for ensuring normal ripening before frost begins. FUL belongs to the MADS‐box transcription factor family and has several duplicated members in soybeans. In this study, we observed that overexpression of GmFULc in the Dongnong 50 cultivar promoted soybean maturity, while GmFULc knockout mutants exhibited late maturity. Chromatin immunoprecipitation sequencing (ChIP‐seq) and RNA sequencing (RNA‐seq) revealed that GmFULc could bind to the CArG, bHLH and homeobox motifs. Further investigation revealed that GmFULc could directly bind to the CArG motif in the promoters of the GmZTL3 and GmZTL4 genes. Overexpression of GmZTL4 promoted soybean maturity, whereas the ztl4 mutants exhibited delayed maturity. Moreover, we found that the cis element box 4 motif of the GmZTL4 promoter, a motif of light response elements, played an important role in controlling the growth period. Deletion of this motif shortened the growth period by increasing the expression levels of GmZTL4. Functional investigations revealed that short‐day treatment promoted the binding of GmFULc to the promoter of GmZTL4 and inhibited the expression of E1 and E1Lb, ultimately resulting in the promotion of flowering and early maturation. Taken together, these findings suggest a novel photoperiod regulatory pathway in which GmFULc directly activates GmZTL4 to promote earlier maturity in soybean. [ABSTRACT FROM AUTHOR]

This article studied the changes in the main active ingredients and antioxidant activity of Shaanxi Fuzhuan brick tea at different flowering stages. The study found that the soluble protein, total polyphenols, and free amino acid content of the three groups of samples from Fuzhuan brick tea showed an overall downward trend on the 1st, 5th, and 20th day of flowering, while the total flavonoids showed a first decreasing and then increasing trend (p< 0.05). The overall soluble sugar content showed a trend of first increasing and then decreasing, with the content of rhamnose and glucose showing an overall downward trend, the content of arabinose and galactose showing a trend of first decreasing and then increasing, the content of mannose showing an upward trend, and the content of xylose remaining unchanged (p<0.05). On the 1st, 5th, and 20th day of blooming, the antioxidant activity indicators of the three groups of samples showed a positive correlation with sample concentration, including reducing ability, ferrous ion chelating ability, and ABTS free radical scavenging ability. They all exhibited good antioxidant activity at high sample concentrations. At low concentrations (0.01~0.05 mg/mL), the reducing power on the 5th and 20th day of flowering was significantly enhanced compared to the first day (p<0.05). The research results can provide theoretical basis for the standardized processing and development and utilization of Fuzhuan tea. [ABSTRACT FROM AUTHOR]

Acer mono is thought to comprise seven varieties, but its classification and nomenclature are controversial. A recent molecular phylogenetic study suggested that A. mono varieties glabrum (G) and mayrii (M) do not interbreed, despite occurring syntopically (same location) and having a common genetic origin. However, if these are separate, reproductively isolated species, the basis for that isolation remains unclear. Here, we tested whether G and M can be considered separate species that differ in multiple ecological characteristics. We compared G and M in terms of distribution, habitats, drought tolerance of leaves, and flowering phenology of trees, and we verified their reproductive isolation (RI) in Japan. G showed higher drought and salt tolerance than M, which is consistent with the distribution of G in salt‐stressed coastal areas with relatively low precipitation. In contrast, M occurs in snowy, mesic, and mountain habitats. Even in neighboring M and G trees, the onset of flowering in M is earlier than that of G. Similarly, flower drop in M is completed sooner than in G. Although the presence of post‐zygotic reproductive barriers was not tested, the high calculated RI index probably contributes to RI. Two varieties of A. mono with a common genetic origin but different drought tolerance should be considered separate species. They likely shifted their climatic niches, involving local adaptation to different climatic conditions. This is roughly supported by an ENM‐based niche analysis and significant differences in flowering time. These findings help to understand the physiological diversification of A. mono. [ABSTRACT FROM AUTHOR]

Long-term exposure to cold during the winter season, so-called vernalization, triggers the transition from the vegetative to the reproductive stage in many biennial and perennial plants. In the last decades, intensive researches have revealed the molecular mechanisms underlying this phenomenon, particularly using Arabidopsis model plant. Most Brassicaceae family plants, including the Arabidopsis, require vernalization for floral transition. Brassicaceae family plants can be classified into two groups: seed vernalization responsive type and plant vernalization responsive type. Cabbage belongs to plant vernalization responsive type. Molecular details on plant vernalization responsive trait of cabbage on vernalization are still poorly understood. In this study, we conducted a transcriptomic analysis of the cabbage inbred line 'BN2348' in response to vernalization. Similar to the case of Arabidopsis, two VIN3 homologs (BoVIN3.C3 and BoVIN3.C2) were highly induced by the exposure to long-term cold in B. oleracea. Our transcriptome analysis identified that two FT homologs (BoFT.C2 and BoFT.C6) and three SOC1 homologs (BoSOC1.1.C4, BoSOC1.2.C4, and BoSOC1.C3) were functioning for the regulation of floral transition in B. oleracea. In addition, by phylogenic and syntenic analyses, a total of five FLC homologs, named BoFLC1.a, BoFLC1.b, BoFLC2, BoFLC3, and BoFLC5, were identified in the genome of B. oleracea. Transcriptomic analysis indicated that these genes could be grouped into vernalization-responsive (BoFLC2 and BoFLC3) and vernalization-insensitive genes (BoFLC1.a, BoFLC1.b, and BoFLC5). As green plant vernalization type, it might suggest the existence of vernalization-insensitive BoFLC homologs in young seedlings might be the reason why cabbage exhibits longer exposure of cold compared to seed vernalization type plants such as Chinese cabbage and Arabidopsis. These findings improve our understanding of the molecular dynamics underlying floral transition in cabbage plants. [ABSTRACT FROM AUTHOR]

Main conclusion: BcERF98 is induced by ethylene signaling and inhibits the expression of BcFT by interacting with BcNF-YA2 and BcEIP9, thereby inhibiting plant flowering. Several stresses trigger the accumulation of ethylene, which then transmits the signal to ethylene response factors (ERFs) to participate in the regulation of plant development to adapt to the environment. This study clarifies the function of BcERF98, a homolog of AtERF98, in the regulation of plant flowering time mediated by high concentrations of ethylene. Results indicate that BcERF98 is a nuclear and the cell membrane-localized transcription factor and highly responsive to ethylene signaling. BcERF98 inhibits the expression of BcFT by interacting with BcEIP9 and BcNF-YA2, which are related to flowering time regulation, thereby participating in ethylene-mediated plant late flowering regulation. The results have enriched the theoretical knowledge of flowering regulation in non-heading Chinese cabbage (NHCC), providing the scientific basis and gene reserves for cultivating new varieties of NHCC with different flowering times. [ABSTRACT FROM AUTHOR]

Mountain meadows are an essential part of the alpine–subalpine ecosystem; they provide ecosystem services like pollination and are home to diverse plant communities. Changes in climate affect meadow ecology on multiple levels, for example, by altering growing season dynamics. Tracking the effects of climate change on meadow diversity through the impacts on individual species and overall growing season dynamics is critical to conservation efforts. Here, we explore how to combine crowd‐sourced camera images with machine learning to quantify flowering species richness across a range of elevations in alpine meadows located in Mt. Rainier National Park, Washington, USA. We employed three machine‐learning techniques (Mask R‐CNN, RetinaNet and YOLOv5) to detect wildflower species in images taken during two flowering seasons. We demonstrate that deep learning techniques can detect multiple species, providing information on flowering richness in photographed meadows. The results indicate higher richness just above the tree line for most of the species, which is comparable with patterns found using field studies. We found that the two‐stage detector Mask R‐CNN was more accurate than single‐stage detectors like RetinaNet and YOLO, with the Mask R‐CNN network performing best overall with mean average precision (mAP) of 0.67 followed by RetinaNet (0.5) and YOLO (0.4). We found that across the methods using anchor box variations in multiples of 16 led to enhanced accuracy. We also show that detection is possible even when pictures are interspersed with complex backgrounds and are not in focus. We found differential detection rates depending on species abundance, with additional challenges related to similarity in flower characteristics, labeling errors and occlusion issues. Despite these potential biases and limitations in capturing flowering abundance and location‐specific quantification, accuracy was notable considering the complexity of flower types and picture angles in this dataset. We, therefore, expect that this approach can be used to address many ecological questions that benefit from automated flower detection, including studies of flowering phenology and floral resources, and that this approach can, therefore, complement a wide range of ecological approaches (e.g., field observations, experiments, community science, etc.). In all, our study suggests that ecological metrics like floral richness can be efficiently monitored by combining machine learning with easily accessible publicly curated datasets (e.g., Flickr, iNaturalist). [ABSTRACT FROM AUTHOR]

BMI1 is the main component of the Polycomb Group Complex 1 (PRC1), which functions as an important epigenetic inhibitor of various regulatory genes associated with shoot apical meristem, embryonic development, flowering, senescence and so on. However, its role in the regulation of grapevine development is still unclear. In order to explore the function of VvBMI1a gene in the regulation of flowering in Vitis vinifera 'Cabernet Sauvignon', the subcellular localization, expression pattern, yeast two-hybrid, two-molecule fluorescence complementation and flowering time of transgenic Arabidopsis were analyzed. The results showed that VvBMI1a, a member of RING domain-containing proteins family from grapevine (Vitis vinifera), is involved in controlling plant flowering time. Expression of VvBMI1a was abundant in the shoot tips and inflorescence meristems of grapevine. VvBMI1a protein is localized in the nucleus. VvBMI1a could interact with VvRING1a protein which belonged to PRC1. Phenotypic analysis showed that VvBMI1a over-expression lines had earlier flowering time than wild-type plants under long-day (LD) conditions. Further analysis by qRT-PCR and transcriptome suggests that both the suppression of FLC and activation of FT, SOC1, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 5 (SPL5), AGL8 were observed in VvBMI1a-overexpressing lines, resulting in early flowering. Our results provide the evidence demonstrating the effectiveness of manipulating VvBMI1a to alter the flowering time of plants. In a word, ectopic overexpression of VvBMI1a inhibited the expression of FLC, activated the expression of FT, SPL5, AGL8 to alter the flowering time of Arabidopsis plants. Key message: • VvBMI1a is a ubiquitously expressed nuclear protein. • VvBMI1a can interact with VvRING1a. • Ectopic overexpression of VvBMI1a induced the early flowering via inhibition of FLC, activation of FT, SPL5, AGL8 expression. [ABSTRACT FROM AUTHOR]

Background: White lupin (Lupinus albus L.) is a high-protein Old World grain legume with remarkable food and feed production interest. It is sown in autumn or early spring, depending on the local agroclimatic conditions. This study aimed to identify allelic variants associated with vernalization responsiveness, in order to improve our knowledge of legume flowering regulatory pathways and develop molecular selection tools for the desired phenology as required for current breeding and adaptation to the changing climate. Results: Some 120 white lupin accessions originating from a wide range of environments of Europe, Africa, and Asia were phenotyped under field conditions in three environments with different intensities of vernalization, namely, a Mediterranean and a subcontinental climate sites of Italy under autumn sowing, and a suboceanic climate site of France under spring sowing. Two hundred sixty-two individual genotypes extracted from them were phenotyped in a greenhouse under long-day photoperiod without vernalization. Phenology data, and marker data generated by Diversity Arrays Technology sequencing (DArT-seq) and by PCR-based screening targeting published quantitative trait loci (QTLs) from linkage map and newly identified insertion/deletion polymorphisms in the promoter region of the FLOWERING LOCUS T homolog, LalbFTc1 gene (Lalb_Chr14g0364281), were subjected to a genome-wide association study (GWAS). Population structure followed differences in phenology and isolation by distance pattern. The GWAS highlighted numerous loci significantly associated with flowering time, including four LalbFTc1 gene promoter deletions: 2388 bp and 2126 bp deletions at the 5' end, a 264 bp deletion in the middle and a 28 bp deletion at the 3' end of the promoter. Besides LalbFTc1 deletions, this set contained DArT-seq markers that matched previously published major QTLs in chromosomes Lalb_Chr02, Lalb_Chr13 and Lalb_Chr16, and newly discovered QTLs in other chromosomes. Conclusions: This study highlighted novel QTLs for flowering time and validated those already published, thereby providing novel evidence on the convergence of FTc1 gene functional evolution into the vernalization pathway in Old World lupin species. Moreover, this research provided the set of loci specific for extreme phenotypes (the earliest or the latest) awaiting further implementation in marker-assisted selection for spring- or winter sowing. [ABSTRACT FROM AUTHOR]

Background: Cicer arietinum is a significant legume crop cultivated mainly in short-season environments, where early-flowering is a desirable trait to overcome terminal constraints. Despite its agricultural significance, the genetic control of flowering time in chickpea is not fully understood. In this study, we developed, phenotyped, re-sequenced and genetically characterized a pair of near-isogenic lines (NILs) with contrasting days to flowering to identify candidate gene variants potentially associated with flowering time. Results: In addition to days to flowering, noticeable differences in multiple shoot architecture traits were observed between the NILs. The resequencing data confirms that the NILs developed in this study serve as appropriate plant materials, effectively constraining genetic variation to specific regions and thereby establishing a valuable resource for future genetic and functional investigations in chickpea research. Leveraging bioinformatics tools and public genomic datasets, we identified homologs of flowering-related genes from Arabidopsis thaliana, including ELF3 and, for the first time in chickpea, MED16 and STO/BBX24, with variants among the NILs. Analysis of the allelic distribution of these genes revealed their preservation within chickpea diversity and their potential association with flowering time. Variants were also identified in members of the ERF and ARF gene families. Furthermore, in silico expression analysis was conducted elucidating their putative roles in flowering. Conclusions: While the gene CaELF3a is identified as a prominent candidate, this study also exposes new targets in chickpea, such as CaMED16b and LOC101499101 (BBX24-like), homologs of flowering-related genes in Arabidopsis, as well as ERF12 and ARF2. The in silico expression characterization and genetic variability analysis performed could contribute to their use as specific markers for chickpea breeding programs. This study lays the groundwork for future investigations utilizing this plant material, promising further insights into the complex mechanisms governing flowering time in chickpea. [ABSTRACT FROM AUTHOR]

Natural selection on traits expressed repeatedly by individuals is usually investigated with a focus on mean values, although within‐individual trait distributions often differ also in other aspects, such as their spread and shape. In plants producing multiple flowers during a season, there might not be a single optimal flowering time, but rather an optimal distribution of flower opening dates. This optimal distribution might depend on both resource allocation patterns and interactions with the abiotic and biotic environment. In this study, we quantified mean, variance, skewness and kurtosis of 495 individual flowering schedules (5287 flowers) over 3 years, and assessed phenotypic selection on these aspects of the within‐individual distribution of opening dates in the perennial herb Lathyrus vernus. We also explored how selection on within‐individual variation in flowering schedules was related to effects on two fitness components: fruit set and the proportion of seeds escaping pre‐dispersal predation. Within‐individual variation in phenology was larger than, or at least similar to, among‐individual variation in all years. We found phenotypic selection on several aspects of individual flowering schedules. In 1 year, selection favoured plants with higher variance in opening dates, and this coincided with a higher fruit set in plants with an increased spread of the flowering schedule. In two of the study years, selection favoured a higher asymmetry of the flowering schedule, and plants with more right‐skewed distributions had higher fruit set and higher proportions of seeds escaping predation. Both fruit set and seed predation increased with an earlier mean flowering, resulting in no net selection on mean flowering date. Synthesis: Our results suggest that phenotypic selection on the spread and shape of flower opening date distributions might be at least as important as selection on the mean flowering date. In a broad sense, this implies that we should consider the entire trait distribution if we aim to understand the evolution of traits that are expressed multiple times within individuals. [ABSTRACT FROM AUTHOR]

Plants are sessile by nature, and as such they have evolved to sense changes in seasonality and their surrounding environment, and adapt to these changes. One prime example of this is the regulation of flowering time in angiosperms, which is precisely timed by the coordinated action of two proteins: FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1). Both of these regulators are members of the PHOSPHATIDYLETHANOLAMINE BINDING PROTEIN (PEBP) family of proteins. These regulatory proteins do not interact with DNA themselves, but instead interact with transcriptional regulators, such as FLOWERING LOCUS D (FD). FT and TFL1 were initially identified as key regulators of flowering time, acting through binding with FD; however, PEBP family members are also involved in shaping plant architecture and development. In addition, PEBPs can interact with TCP transcriptional regulators, such as TEOSINTE BRANCHED 1 (TB1), a well-known regulator of plant architecture, and key domestication-related genes in many crops. Here, we review the role of PEBPs in flowering time, plant architecture, and development. As these are also key yield-related traits, we highlight examples from the model plant Arabidopsis as well as important food and feed crops such as, rice, barley, wheat, tomato, and potato. [ABSTRACT FROM AUTHOR]

Understanding the process of Prunus species floral development is crucial for developing strategies to manipulate bloom time and prevent crop loss due to climate change. Here, we present a detailed examination of flower development from initiation until bloom for early- and late-blooming sour cherries (Prunus cerasus) from a population segregating for a major bloom time QTL on chromosome 4. Using a new staging system, we show floral buds from early-blooming trees were persistently more advanced than those from late-blooming siblings. A genomic DNA coverage analysis revealed the late-blooming haplotype of this QTL, k , is located on a subgenome originating from the late-blooming P. fruticosa progenitor. Transcriptome analyses identified many genes within this QTL as differentially expressed between early- and late-blooming trees during the vegetative-to-floral transition. From these, we identified candidate genes for the late bloom phenotype, including multiple transcription factors homologous to Reproductive Meristem B3 domain-containing proteins. Additionally, we determined that the basis of k in sour cherry is likely separate from candidate genes found in sweet cherry—suggesting several major regulators of bloom time are located on Prunus chromosome 4. [ABSTRACT FROM AUTHOR]

The timing of the developmental transition from the vegetative to the reproductive stage is critical for angiosperms, and is fine-tuned by the integration of endogenous factors and external environmental cues to ensure successful reproduction. Plants have evolved sophisticated mechanisms to response to diverse environmental or stress signals, and these can be mediated by hormones to coordinate flowering time. Phytohormones such as gibberellin, auxin, cytokinin, jasmonate, abscisic acid, ethylene, and brassinosteroids and the cross-talk among them are critical for the precise regulation of flowering time. Recent studies of the model flowering plant Arabidopsis have revealed that diverse transcription factors and epigenetic regulators play key roles in relation to the phytohormones that regulate floral transition. This review aims to summarize our current knowledge of the genetic and epigenetic mechanisms that underlie the phytohormonal control of floral transition in Arabidopsis, offering insights into how these processes are regulated and their implications for plant biology. [ABSTRACT FROM AUTHOR]

Background: Improving the rate of genetic gain of cereal crop will rely on the accelerated crop breeding pipelines to allow rapid delivery of improved crop varieties. The laborious, time-consuming traditional breeding cycle, and the seasonal variations are the key factor restricting the breeder to develop new varieties. To address these issues, a revolutionized cost-effective speed breeding protocol for large-scale rice germplasm advancement is presented in the present study. The protocol emphasises on optimizing potting material, balancing the double-edged sword of limited nutritional dose, mode and stage of application, plant density, temperature, humidity, light spectrum, intensity, photoperiod, and hormonal regulation to accelerate rice growth and development. Results: The plant density of 700 plants/m2, cost-effective halogen tubes (B:G:R:FR-7.0:27.6:65.4:89.2) with an intensity of ∼ 750–800 µmol/m2/s and photoperiod of 13 h light and 11 h dark during seedling and vegetative stage and 8 h light and 16 h dark during reproductive stage had a significant effect (P < 0.05) on reducing the mean plant height, tillering, and inducing early flowering. Our results confirmed that one generation can be achieved within 68–75 days using the cost-effective SpeedyPaddy protocol resulting in 4–5 generations per year across different duration of rice varieties. The other applications include hybridization, trait-based phenotyping, and mapping of QTL/genes. The estimated cost to run one breeding cycle with plant capacity of 15,680 plants in SpeedyPaddy was $2941 including one-time miscellaneous cost which is much lower than the advanced controlled environment speed breeding facilities. Conclusion: The protocol offers a promising cost-effective solution with average saving of 2.0 to 2.6 months per breeding cycle with an integration of genomics-assisted selection, trait-based phenotyping, mapping of QTL/genes, marker development may accelerate the varietal development and release. This outstanding cost-effective break-through marks a significant leap in rice breeding addressing climate change and food security. [ABSTRACT FROM AUTHOR]

Genetic gains made by plant breeders are limited by generational cycling rates and flowering time. Several efforts have been made to reduce the time to switch from vegetative to reproductive stages in plants, but these solutions are usually species-specific and require flowering. The concept of in vitro nurseries is that somatic plant cells can be induced to form haploid cells that have undergone recombination (creating artificial gametes), which can then be used for cell fusion to enable breeding in a Petri dish. The induction of in vitro meiosis, however, is the largest current bottleneck to in vitro nurseries. To help overcome this, we previously described a high-throughput, bi-fluorescent, single cell system in Arabidopsis thaliana, which can be used to test the meiosis-like induction capabilities of candidate factors. In this present work, we validated the system using robust datasets (>4M datapoints) from extensive simulated meiosis induction tests. Additionally, we determined false-detection rates of the fluorescent cells used in this system as well as the ideal tissue source for factor testing. [ABSTRACT FROM AUTHOR]

Flowering time is a crucial adaptive response to seasonal variation in plants and is regulated by environmental cues such as photoperiod and temperature. In this study, we demonstrated the regulatory function of rice CRYPTOCHROME‐INTERACTING BASIC HELIX‐LOOP‐HELIX 1‐LIKE (OsCIBL1) in flowering time. Overexpression of OsCIB1L promoted flowering, whereas the oscib1l knockout mutation did not alter flowering time independent of photoperiodic conditions. Cryptochromes (CRYs) are blue light photoreceptors that enable plants to sense photoperiodic changes. OsCIBL1 interacted with OsCRY2, a member of the rice CRY family (OsCRY1a, OsCRY1b, and OsCRY2), and bound to the Early heading date 1 (Ehd1) promoter, activating the rice‐specific Ehd1‐Heading date 3a/RICE FLOWERING LOCUS T 1 pathway for flowering induction. Dual‐luciferase reporter assays showed that the OsCIBL1‐OsCRY2 complex required blue light to induce Ehd1 transcription. Natural alleles resulting from nonsynonymous single nucleotide polymorphisms in OsCIB1L and OsCRY2 may contribute to the adaptive expansion of rice cultivation areas. These results expand our understanding of the molecular mechanisms controlling rice flowering and highlight the importance of blue light‐responsive genes in the geographic distribution of rice. [ABSTRACT FROM AUTHOR]

Foliar application of mineral nutrients can considerably improve fruit yield and quality. In this study, the effects of K and Zn application by spraying on leaf mineral contents, and some physical and biochemical characteristics of pomegranate fruits cv. 'Malas Saveh' were investigated. The mineral treatments were three concentrations of K2SO4 (0, 1, and 2%) and three concentrations of ZnSO4 (0, 0.5, and 1%). The solutions were applied in 2020–2021 and in four times: the first application was during the time of flowering and rest three applications were applied at two-week intervals. The results showed that leaves of trees fed with different concentrations of K2SO4 and ZnSO4 accumulated higher concentrations of N, P K, Zn, Fe, and Mn than those untreated. Pomegranate trees treated with the mineral treatments had higher chlorophyll a and total chlorophyll. Applying most mineral treatments, especially 2% K2SO4+0.5% ZnSO4, significantly increased the fruit yield, fruit diameter, fruit length, aril percentage, aril/skin, the weight of 100 arils, and juice content of 100 g arils, but reduced the cracking percentage, skin thickness, skin percentage and firmness of fruits. Moreover, fruits of pomegranate trees treated with the most mineral treatments and especially 2% K2SO4+0.5% ZnSO4, showed a greater level of TSS (total soluble solids), TSS/TA (total soluble solids/titratable acidity), anthocyanin, total phenol, flavonoid, antioxidant activity, and vitamin C, and a lower level of TA. The study results evidenced that K and Zn application by spraying has a high potential for improving fruit yield and quality of pomegranate. [ABSTRACT FROM AUTHOR]

SUMMARY: Transcriptome‐wide association studies (TWAS) can provide single gene resolution for candidate genes in plants, complementing genome‐wide association studies (GWAS) but efforts in plants have been met with, at best, mixed success. We generated expression data from 693 maize genotypes, measured in a common field experiment, sampled over a 2‐h period to minimize diurnal and environmental effects, using full‐length RNA‐seq to maximize the accurate estimation of transcript abundance. TWAS could identify roughly 10 times as many genes likely to play a role in flowering time regulation as GWAS conducted data from the same experiment. TWAS using mature leaf tissue identified known true‐positive flowering time genes known to act in the shoot apical meristem, and trait data from a new environment enabled the identification of additional flowering time genes without the need for new expression data. eQTL analysis of TWAS‐tagged genes identified at least one additional known maize flowering time gene through trans‐eQTL interactions. Collectively these results suggest the gene expression resource described here can link genes to functions across different plant phenotypes expressed in a range of tissues and scored in different experiments. Significance Statement: Large, deep and rapidly sampled RNA‐seq data produce great TWAS results, and discovering genes known to act in other tissues and using data from other experiments suggests these data can be reused to study other traits. [ABSTRACT FROM AUTHOR]

Many species of Sapindaceae, such as lychee, longan, and rambutan, provide nutritious and delicious fruit. Understanding the molecular genetic mechanisms that underlie the regulation of flowering is essential for securing flower and fruit productivity. Most endogenous and exogenous flowering cues are integrated into the florigen encoded by FLOWERING LOCUS T. However, the regulatory mechanisms of flowering remain poorly understood in Sapindaceae. Here, we identified 60 phosphatidylethanolamine-binding protein-coding genes from six Sapindaceae plants. Gene duplication events led to the emergence of two or more paralogs of the FT gene that have evolved antagonistic functions in Sapindaceae. Among them, the FT1-like genes are functionally conserved and promote flowering, while the FT2-like genes likely serve as repressors that delay flowering. Importantly, we show here that the natural variation at nucleotide position − 1437 of the lychee FT1 promoter determined the binding affinity of the SVP protein (LcSVP9), which was a negative regulator of flowering, resulting in the differential expression of LcFT1, which in turn affected flowering time in lychee. This finding provides a potential molecular marker for breeding lychee. Taken together, our results reveal some crucial aspects of FT gene family genetics that underlie the regulation of flowering in Sapindaceae. [ABSTRACT FROM AUTHOR]

Introduction: Phosphorus (P) and potassium (K) deficiencies are increasingly being reported in Ghana's interior savanna soils. Smallholder farmers consider soybeans as a "zero-input" crop resulting in low yields and profitability. Studies indicate a positive response to P application; however, knowledge of the synergistic effect of P and K in soybeans is limited. A six-site year experiment was conducted to evaluate the synergy of P and K for soybean yield, partial factor productivity (PFP), agronomic efficiency (AE), rain-use efficiency (RUE), and variable-cost ratio (VCR). Materials and methods: The treatments were 4 × 4 factorial combinations of P at 0, 25, 50, and 100 P2O5 (kg ha-1) and K at 0, 25, 50, and 100 K2O (kg ha-1), and their combinations laid out in a randomized complete block design with four replications. The soybean cultivar "Favor" (TGx 1844-22E), released and registered by the Savanna Agricultural Research Institute (SARI), was used as the test crop. Results and discussion: Flowering time was reduced at Nyankpala and Dokpong by 0.2 and 0.4 (days), while plant height was increased by 4%-18% over control. Yield and RUE increased as P and K rates increased, with the greatest yield from T15 (P100K50) in Manga (2.34 t ha-1) and Nyankpala (2.37 t ha-1), T16 (P100K100) at Dokpong (2.68 t ha-1), and RUE from T15 across locations. The PFP, AE, and VCR values decreased with increasing P and K rates, with the greatest PFP, AE, and VCR from T5 (P25K0) at Manga and Dokpong and T2 (P0K25) at Nyankpala. All treatments exceeded the VCR > 2.0 threshold, except T12 (P50K100) across locations, and T16 at Manga and Nyankpala. The greatest economic returns are T5 at Manga and Dokpong and T2 at Nyankpala. Conclusion: By all indications, the study justified the use of nutrient input in soybeans of P and K to enhance grain yield and profitability. Avoiding broadcast applications and adopting precision placement using the 4R nutrient principles of right placement, right fertilizer source, right rate, and the right time is key. The study recommends further experiments on different combinations of P and K in a long-term residual study. [ABSTRACT FROM AUTHOR]