Flowering Time Research Articles

TMT-label comparative proteomics reveals the vernalization mechanism in Wucai (Brassica campestris L.).

To investigate the molecular basis of vernalization in Wucai [Brassica campestris L. (Syn. Brassica rapa L.) ssp. chinensis var. rosularis Tsen], we performed differential proteomic analysis using a tandem mass tags (TMT)-based approach. Proteins from shoot apices subjected to 0, 15, and 30 days of vernalization (V0, V15, and V30) were analyzed to identify differentially abundant proteins (DAPs). A total of 8066 proteins were obtained, and 507 shared DAPs were involved in both initiation and progression of vernalization. Gene Ontology (GO) and Gene Ontology (KEGG) annotations revealed functional enrichment in cellular processes, metabolic pathways, and translation-related activities, including photosynthesis, glucosinolate biosynthesis, and flavonoid biosynthesis. Proteomic data showed reduced abundance of photosynthesis-related proteins and upregulation of flavonoid biosynthesis during vernalization. Transcriptional validation of 24 proteins across metabolic and regulatory pathways corroborated proteomic findings, with notable peaks in genes associated with flavonoid biosynthesis at 15 days of vernalization, such as VESR1,CH13, CHS1, FHT, and FLS1. The functions of these genes in vernalization will be further analyzed. SIGNIFICANCE: Wucai is prone to premature bolting and flowering under cold conditions, as vernalization plays a key role in controlling flowering time in Chinese cabbage crops. However, the proteomic basis of vernalization remains poorly understood. In this study, TMT-based proteomic analysis identified DAPs associated with vernalization. Pathway enrichment analysis highlighted key DAPs and their roles in significantly enriched pathways relevant to vernalization. Notably, genes in the flavonoid biosynthesis pathway genes, including VESR1, CH13, CHS1, FHT, and FLS1, respond to vernalization. These findings offer novel insights into the molecular mechanisms underlying flowering time regulation in Wucai.

Exploring climate-driven phenological mismatches in pears, pests and natural enemies: a multi-model approach

Abstract Pear psyllid (Cacopsylla pyri) is the dominant pest of UK pear orchards, with an estimated cost of £5 million per annum. Insecticide withdrawal and increased pesticide resistance of C. pyri have led many growers to depend more on natural enemies for pest management, including earwigs. However, there is concern how phenological events may shift with future climate change, which may result in phenological mismatches. This study aimed to determine shifts in timing of phenological events within an agroecosystem and predict phenological mismatches or synchronies between trophic levels. We evaluated three models: the C. pyri phenology model, the earwig degree day model and the PhenoFlex model (flowering time). Phenological events predicted by models included: first, full and last flowering time for Pyrus communis; peak psyllid abundance date for first-generation (G1) C. pyri nymphs and second-generation (G2) eggs, nymphs and adults; and peak abundance date for stage 4 Forficula auricularia and adults. Findings indicated that the timing of phenological events was advancing for all trophic levels, becoming significantly earlier under the current time period. Furthermore, predictions indicated that timing events would continue to advance under the RCP8.5 scenario. However, not all phenological events advanced at the same rate; the date of peak C. pyri G1 nymph abundance advanced at a higher rate than full flowering time, which could result in a phenological mismatch by 2071. Conversely, C. pyri and F. auricularia showed phenological synchrony, with peak abundance dates advancing at a similar rate, which could be beneficial for future biological control.

Unveiling Photoperiod-Responsive Regulatory Networks in Tropical Maize Through Transcriptome Analysis

Background/Objectives: Maize (Zea mays L.), a crop of worldwide importance, owes its adaptability to diverse environments to its genetic variation. However, tropical maize exhibits intrinsic photoperiod sensitivity, limiting its adaptability to temperate regions. Photoperiod sensitivity significantly affects the flowering time and other agronomic traits, but the underlying molecular mechanisms remain poorly understood. In this study, the aim is to elucidate the transcriptional regulatory networks mediating photoperiod responses in tropical maize inbred line Su65, providing insights into improving photoperiod adaptability. Methods: RNA-seq analysis was carried out to investigate photoperiod-responsive genes and pathways in tropical line Su65 exposed to varying photoperiod conditions. Differential expression analysis, functional enrichment, and the construction of protein–protein interaction (PPI) networks were carried out to investigate transcriptional dynamics. Additionally, qRT-PCR was employed to confirm the expression patterns of key candidate genes and generate detailed temporal expression profiles. Results: A total of 1728 differentially expressed genes (DEGs) were identified, with significant enrichment in pathways such as stress responses, redox homeostasis, and secondary metabolite biosynthesis. A set of new key hub genes (such as Zm00001d048531, Zm00001d018821, Zm00001d034892, etc.) were identified through PPI network analysis. Temporal expression profiling of ZmPHYB1, ZmPHYC1, ZmFKF2, ZmGI2, and ZmPRR37a, the key genes involved in circadian rhythms, revealed distinct regulatory patterns of photoperiod-sensitive genes at different time points, highlighting their roles in flowering time regulation and developmental transitions. Conclusions: In this study, critical molecular networks underlying photoperiod sensitivity in tropical maize are uncovered and a foundation is provided for improving photoperiod adaptability through genetic improvement. By integrating RNA-seq and qRT-PCR, the research offers valuable insights into transcriptional dynamics and their role in maize development under photoperiodic regulation.

Comprehensive genome-wide analysis of ARF transcription factors in orchardgrass (Dactylis glomerata): the positive regulatory role of DgARF7 in drought resistance

Auxin response factor (ARF), a transcription factor, is crucial in controlling growth, development, and response to environmental stress. Orchardgrass (Dactylis glomerata) is an economically significant, widely cultivated forage grass. However, information on the genome-wide information and functional characterization of ARFs in orchardgrass is limited. This study identified 27 ARF genes based on the orchardgrass genome database. These DgARFs were unevenly distributed across the seven orchardgrass chromosomes and clustered into four classes. Phylogenetic analysis with multispecies of ARF proteins indicated that the ARFs exhibit a relatively conserved evolutionary path. Focusing on hormone signaling responses, DgARF7 demonstrated a potential positive regulatory role in response to 3-indole acetic acid, methyl jasmonate, gibberellin, salicylic acid, and abscisic acid signals. Additionally, exposure to drought stress induced noticeable oscillatory changes in DgARF7 gene. Notably, DgARF7 enhanced drought tolerance through heterologous expression in yeast and overexpression in Arabidopsis. Overexpressed Arabidopsis lines of DgARF7 exhibited a markedly higher relative water content and superoxide dismutase activity, while the malondialdehyde content was significantly decreased compared to wild type under drought stress. DgARF7 also accelerated flowering time by inducing the flowering-related gene expression levels in Arabidopsis. This research provides important insights into the role of DgARF7 in orchardgrass and provides further understanding in molecular breeding.

Multiple combinatorial interactions among natural structural variants of Brassica SOC1 promoters and SVP: conservation of binding affinity despite diversity in bimolecular interactions.

Analysis of binding patterns of biomolecules underpin new paradigms for trait engineering. One way of designing early flowering crops is to manipulate genes controlling flowering time. SOC1, a central integrator of flowering, is downregulated by SVP. In amphidiploid Brassica juncea, flowering is plausibly mediated by combinatorial interactions involving natural variants of SOC1 promoter and SVP protein homologs. Although fluctuating temperatures influence energetics of molecular interactions and phenotypes, mechanistic insights on these remain unknown. Herein, we report diversity in 50 homologs of SVP proteins from 25 Brassicaceae species. Sequence and phylogenetic analysis of 9 natural variants of B. juncea SVP revealed differences in MIKC domains and sub-genome of origin. Generation and refinement of 15 SVP protein models (natural and hypothetical) using I-TASSER and ALPHAFOLD, and 3 SOC1 promoter fragments using 3D-DART, revealed structural diversity. Notwithstanding, binding affinity of 48 docked complexes analysed using HADDOCK and PreDBA were similar. Analysis of 27 docked complexes for distribution of shared or unique binding patterns and type of molecular contacts (π-π stacking, hydrophobic interactions, Van-der-Waals forces, H-bonds) using PyMOL, CCP4i, DNAproDB, PremPDI and DIMPLOT revealed extensive variation implicating compensatory mutations in preserving binding affinity. Yeast one-hybrid assays validated binding potential predicted in docked complexes. Conserved amino-acid and nucleotide residues involved in non-covalent interactions were identified. Computational alanine substitution established cruciality of amino-acid hotspots conferring stability to docked complexes. Our study is important as identification of crucial amino-acid hotspots is essential for rational protein design. Targeted mutagenesis resulting in modified binding spectrum of regulatory proteins suggests a way forward for trait engineering.

The essential role of the hickory StMADS11 subfamily in flower organogenesis and flowering time in Arabidopsis.

The StMADS11 subfamily genes play a crucial role in regulating flowering time, flower development, and bud dormancy in plants. These genes exhibit functional differences between annual and perennial woody plants. In hickory (Carya cathayensis Sarg.), the specific roles of these genes in flowering regulation have not been elucidated. In this study, we identified five StMADS11 subfamily genes in the hickory genome, designated as CcSVP-like, CcAGL24-like1, CcAGL24-like2, CcJOINTLESS-like1, and CcJOINTLESS-like2, based on their clustering characteristics. Sequence analyses revealed distinct structural features in this subfamily, including differences in intron length, C domain, and conserved motifs. Transcript analysis indicated high expression levels of these genes in female flower buds, along with a notable seasonal expression pattern. Overexpression studies on Arabidopsis have demonstrated that the StMADS11 subfamily genes lead to various floral organ and pod anomalies. Specifically, overexpression of CcSVP-like resulted in delayed flowering, while overexpression of CcAGL24-like1, CcAGL24-like2, CcJOINTLESS-like1, and CcJOINTLESS-like2 promoted flowering. Protein interaction studies have shown that the StMADS11 subfamily proteins bind to the CcFUL-like protein. Notably, CcFUL-like, CcSVP-like, CcJOINTLESS-like1, and CcJOINTLESS-like2 proteins were able to bind to the CcSOC1-like promoter and suppress its expression. Our findings elucidate the distinct roles of the StMADS11 subfamily genes in flower development and timing, contribute to developing the current understanding of flowering regulation in hickory, and offer a foundation for further studies in perennial woody plants.

CRF12 specifically regulates the flowering time of Arabidopsis thaliana under non-inductive conditions.

The flowering time of Arabidopsis thaliana, a model plant, is significantly accelerated when exposed to long-day (LD) conditions, as it is a typical LD plant. Consequently, the investigation of the flowering regulatory network in A. thaliana under LD conditions has garnered considerable attention in the study of flowering signals, resulting in a significant breakthrough. While many LD plants, including A. thaliana, exhibit delayed flowering under non-inductive short-day (SD) conditions, they are still capable of flowering. Nevertheless, research on the regulation of flowering induction in LD plants under non-inductive SD conditions has been limited. This study demonstrated the involvement of CYTOKININ RESPONSE FACTORS 12 (CRF12) in the regulation of flowering in A. thaliana under non-inductive conditions. Analysis of the expression patterns revealed that the activation of CRF12 expression and protein stability occurred exclusively in non-inductive environments. Molecular and genetic analyses revealed that under a non-inductive photoperiod of 12 h of light and 12 h of darkness, CRF12, CONSTANS (CO), and TARGET OF EAT 1/2 (TOE1/2) engage in competitive interactions to regulate flowering time, while in a SD photoperiod of 8 h of light and 16 h of darkness, CRF12 modulates flowering time by inhibiting the activity of TOE1/2.

OsbZIP23 delays flowering by repressing OsMADS14 expression in rice

Flowering time is a fundamental factor determining the global distribution and final yield of rice (Oryza sativa L.). The initiation of the floral transition process signifies the beginning of the reproductive phase. The florigens Heading Date 3a (Hd3a) and Rice Flowering Locus T 1 (RFT1) combine with GF14 proteins and OsFD-like basic leucine zipper (bZIP) transcription factors to form florigen activation/repressor complexes (FACs/FRCs) that regulate the transition to flowering. We herein report that a bZIP transcription factor (OsbZIP23) functions as a flowering repressor. Transgenic plants overexpressing OsbZIP23 exhibited delayed flowering, which was in contrast to the slightly early flowering of the osbzip23 mutants, under natural short-day and long-day conditions. Molecular and biochemical analyses indicated that OsbZIP23 can bind to the 5′ untranslated region of OsMADS14 and suppress expression. Moreover, it delays the floral transition probably by interacting with OsFTL1/Hd3a/RFT1 and 14-3-3 proteins to form FRCs. Our findings have further elucidated the molecular mechanisms regulating the flowering time in rice.

The FLOWERING LOCUS T-like genes from patchouli (Pogostemon cablin) antagonistically regulate flowering time.

Flowering is crucial for the reproductive success of plants. Patchouli (Pogostemon cablin), a widely utilized medicinal and aromatic plant from the Lamiaceae family, exhibits rare flowering and fails to produce seeds, thereby posing a challenge for plant evolution and breeding improvement. However, the mechanism underlying flowering in patchouli has not been investigated. FLOWERING LOCUS T (FT) serves as a central integrator of flowering signals. Here, we identified 13 patchouli FT-like genes (PatFTs). In patchouli leaves, PatFT10-13 displayed continuous expression, with a decline noted at the flowering stage, while PatFT1-3 were activated exclusively at the flowering stage, and PatFT4-9 were hardly expressed. Overexpression of PatFT2 in Arabidopsis induced early flowering, while overexpression of PatFT10-13 resulted in delayed flowering. These results suggested that PatFT1-3, differing by one to two unique residues in the non-conserved region, might function as floral inducers, while PatFT10-13 likely act as floral repressors. Both PatFT2 and PatFT11 interacted with patchouli FD-like proteins. Transient expression of PatFT11 in protoplasts reduced the ability of PatFT2 to activate downstream flowering genes, suggesting a competitive antagonism between these proteins for shared interactors. Amino acid swapping analysis indicated that specific conserved residues was responsible for the functional switch in PatFTs. Furthermore, we revealed that the evolution of antagonistic FT-like modules might represent a common strategy for Lamiaceae plants to fine-tune flowering time. In summary, these findings provide new insights into the expansion and functional diversity of FT-like genes in patchouli.

Manipulating Propagule Type and Interrow Ground Cover to Influence Flowering Time, Yield, Fruit Quality, and Harvest Dates in the Day-neutral Strawberry ‘Albion’

We examined methods of producing day-neutral strawberries in a north temperate climate using alternatives to standard bare-root propagules and clean cultivation between plant rows. Fragaria ×ananassa ‘Albion’ were planted in plastic-covered raised beds in Ithaca, NY, USA, for each of the 2022 and 2023 growing seasons. Plants were selected from the following four propagule types from different developmental stages: standard bare-root plants set in early May; bare-root plants started in the greenhouse in February and planted in early May; bare-root plants started in the greenhouse in March and planted in early May; and plug plants set in the field in fall (Aug 2021 and Oct 2022) of the previous year. To determine if pollination could be enhanced, each type of plant was grown in plots in the field with one of the following between rows: bare ground; a diverse flowering groundcover; or exclusion netting on hoops over the strawberry plants when they were flowering. Pollinators visiting strawberries were observed weekly and identified to species when possible. Fruits were collected weekly and marketable and unmarketable yields were measured through the harvest season. Fall-planted plugs produced significantly higher marketable yields than those of other propagule types in both years. Bare-root plants set in early May had the lowest yield. Percent marketable yield varied depending on the growing year because of drastically different weather conditions. There was no evidence that flowering groundcover attracted pollinators to the strawberry plants because strawberries had few pollinator visits, regardless of the surrounding vegetation. Exclusion netting had significantly higher percent marketable yield and total yield than the those of other groundcover types despite lower percent fruit set, likely because of the benefits of tarnished plant bug exclusion.

Photoperiodic flowering and AFT/FTL3 gene expression in flowering-time varieties in chrysanthemum.

Chrysanthemum (Chrysanthemum morifolium Ramat.) is a short-day plant, and flowering is stimulated when the photoperiod is shorter than a variety-specific threshold (critical day length). In Japan, summer-to-autumn-flowering cultivars (SA-cvs.) flower from July to September. Little research has been conducted to understand why SA-cvs. bloom earlier than autumn-flowering cultivars (A-cvs.). We conducted a comparative study of the relationship between the photoperiodic response of flowering and the gene expression of florigen FLOWERING LOCUS T-like 3 (FTL3) and antiflorigen anti-florigenic FT/TFL1 (AFT). SA-cvs. had a longer critical day length than A-cvs. However, in both groups, a decrease in AFT and increase in FTL3 were consistently observed below the critical day length when flowering was promoted. The opposite responses (less flowering, low FTL3, and high AFT) were observed for longer than the critical day lengths. This indicated that flowering in SA-cvs. was controlled by the regulation of AFT/FTL3 expression, similar to that in A-cvs. Next, we studied the mechanism that causes a variation in critical day lengths. In SA-cvs., the photosensitive phase, which occurs at night, occurs earlier than that in A-cvs. This indicates a variation in the endogenous time-keeping mechanism. This was supported by the fact that the circadian rhythmicity of leaf movement was weaker in SA-cvs. than that in A-cvs. Thus, variation in the endogenous time-keeping mechanism may cause a longer critical day length and earlier flowering time in SA-cvs.

Genetically-encoded targeted protein degradation technology to remove endogenous condensation-prone proteins and improve crop performance

Effective modulation of gene expression in plants is achievable through tools like CRISPR and RNA interference, yet methods for directly modifying endogenous proteins remain lacking. Here, we identify the E3 ubiquitin ligase E3TCD1 and develope a Targeted Condensation-prone-protein Degradation (TCD) strategy. The X–E3TCD1 fusion protein acts as a genetically engineered degrader, selectively targeting endogenous proteins prone to condensation. For example, a transgenic E3TCD1 fusion with Teosinte branched 1 (TB1) degrades the native TB1 protein, resulting in increased tiller numbers in rice. Additionally, conditional degradation of the negative defense regulator Early Flowering 3 via a pathogen-responsive ProTBF1-uORFsTBF1 cassette enhances rice blast resistance without affecting flowering time in the absence of pathogen. Unlike prevailing targeted protein degradation strategies, the TCD system does not rely on small molecules, antibodies, or genetic knock-in fusion tags, demonstrating its promise as a transgene-based approach for optimizing crop performance.

МОЛЕКУЛЯРНЫЕ ВАРИАЦИИ ГЕНА BTC1 BETA VULGARIS L.

Early flowering of sugar beet plants in the first year of vegetation significantly reduces the productivity of the crop. Therefore, the study and molecular genetic selection of the source material resistant to boltering is relevant. To study the gene that controls the flowering time of sugar beet, leaf blades of domestic supporting lines (O-type) and foreign hybrids selected in the field where this trait was manifested were used. When carrying out the polymerase chain reaction in the experiments, a specific pair of primers F9/R9 was used. Processing of sequencing results and comparative analysis was carried out in the program Geneious Prime. This paper presents the results of studying the BTC1 gene (bolting time control 1), which regulates the flowering process of Beta vulgaris L. Control occurs through the regulation of the activity of two genes belonging to the FT family: an inhibitor (Flowering Time 1) and an activator (Flowering Time 2) of the physiological process – flowering. In genotypes susceptible to flowering, new single nucleotide substitutions in exon 10 were found in the BTC1 gene, initiating substitutions in the amino acid composition of the polypeptide chain, which ultimately leads to the expression of a functionally different protein. The presence of certain SNPs in the BTC1 gene of sugar beet makes it possible with a high degree of probability to characterize certain genotypes as sensitive to early flowering. The experimental data obtained make it possible to select genotypes resistant to early flowering at the early stages of the breeding process. Knowledge about the genetic nature of early flowering is significant when using Beta vulgaris culture in different geographical zones.

Long-day induced flowering requires DNA hypermethylation in orchardgrass.

Flowering, a pivotal plant lifecycle event, is intricately regulated by environmental and endogenous signals via genetic and epigenetic mechanisms. Photoperiod is a crucial environmental cue that induces flowering by activating integrators through genetic and epigenetic pathways. However, the specific role of DNA methylation, a conserved epigenetic marker, in photoperiodic flowering remains unclear. This study integrated methylome, transcriptome, and gene expression analyses in orchardgrass (Dactylis glomerata) to elucidate the molecular mechanisms underlying long-day (LD) flowering. We found that LD treatment led to CHH hypermethylation, which was associated with the increased expression of RNA-dependent DNA methylation pathway components. LD-induced CHH hypermethylation in promoters correlated with upregulated photoperiod pathway genes and down-regulated miRNAs. The suppression of DNA methylation under LD conditions delays flowering, highlighting the critical role of hypermethylation. Additionally, the novel-miR1736-3p was identified as a negative regulator of DgFT. These findings elucidate the promotion of flowering through LD-induced CHH hypermethylation and provide insights into using epigenetic techniques to control plant flowering time.

Construction and evaluation of Brassica rapa orphan genes overexpression library.

Orphan genes (OGs) are crucial for species-specific characteristics and stress responses and are restricted to a specific taxon. However, their functions within particular species are poorly understood. Previous research identified OGs in Brassica rapa (BrOGs). In this study, the BrOGs overexpression (BrOGsOE) library in Arabidopsis thaliana was constructed. Approximately 128 unknown functional BrOGs were selected from Chinese cabbage and were overexpressed. The analysis focused on the phenotypes of leaf morphology and flowering time against phenotypic differences between Chinese cabbage and Arabidopsis. Interestingly, 72.66% of the transgenic lines showed distinctive phenotypic changes. Chinese cabbage-specific features, including curved, hairy, upward or downward-curving leaves, serrated margins, and multiple leaves, were observed in the BrOGsOE lines. The BrOGs overexpression library was associated with numerous variations in flowering time, particularly delayed flowering. This suggested that the delayed flowering time caused by BrOGs may be associated with resistance to bolting seem in Chinese cabbage. Furthermore, the results of stress treatment of 24 BrOGsOE lines with no apparent significant phenotypes suggested that a number of BrOGs have both general and specific functions against environmental and pathogenic stress. The findings of this study provide a comprehensive overview of the roles of BrOGs, emphasizing their significance as a resource for identifying positive genes associated with species-specific characteristics and stress responses and offering a solid foundation for the functional analysis of BrOGs.

Genome-wide identification and expression analysis of CBF/DREB1 gene family in Medicago sativa L. and functional verification of MsCBF9 affecting flowering time

BackgroundThe C-repeat binding factor (CBF)/dehydration-responsive element binding (DREB1) belongs to a subfamily of the AP2/ERF (APETALA2/ethylene-responsive factor) superfamily, which can regulate many physiological and biochemical processes in plants, such as plant growth and development, hormone signal transduction and response to abiotic stress. Although the CBF/DREB1 family has been identified in many plants, studies of the CBF/DREB1 family in alfalfa are insufficient.ResultsIn this study, 25 MsCBF genes were identified in the genome of alfalfa (“Zhongmu No. 4”). These genes were distributed on chromosomes 1, 5, 6 and unassembled scaffolds. Phylogenetics divided the CBF members of Medicago sativa, Arabidopsis thaliana, and Medicago truncatula into six groups, of which group VI had the most MsCBFs members, reaching 52% (13/25). Gene duplication analysis showed that 64% (16/25) of MsCBFs formed tandem duplications, and 32% (8/25) formed segment duplications. The expression pattern of MsCBF9 under different hormone treatments was verified by RT-qPCR, and it was found that MsCBF9 responded to GA3, IAA, SA, and MeJA. Overexpression of MsCBF9 in Arabidopsis significantly delayed the flowering time of Arabidopsis. In contrast, the flowering time of the cbfs mutant was earlier, and overexpression of MsCBF9 also increased the number and size of Arabidopsis rosette leaves.ConclusionIn this study, the CBF/DREB1 family of alfalfa was comprehensively identified and analyzed, and the function of MsCBF9 in regulating flowering time was studied. This study laid a foundation for further analysis of the function of the CBF family in alfalfa.Clinical trial numberNot applicable.

Small molecules and heat treatments reverse vernalization via epigenetic modification in Arabidopsis

Monocarpic plants flower only once and then produce seeds. Many monocarpic plants require a cold treatment known as vernalization before they flower. This requirement delays flowering until the plant senses warm temperatures in the spring. Exposure to high temperatures following vernalization causes devernalization, which cancels the vernalized state, inhibiting flowering and promoting vegetative growth. In this study, we screened over 16,000 chemical compounds and identified five small molecules (devernalizers; DVRs) that induce devernalization in Arabidopsis thaliana at room temperature without requiring a high-temperature treatment. Treatment with DVRs reactivated the expression of FLOWERING LOCUS C (FLC), a master repressor of flowering, by reducing the deposition of repressive histone modifications, thereby delaying flowering time. Three of the DVRs identified shared two structures: a hydantoin-like region and a spiro-like carbon. Treatment with DVR06, which has a simple chemical structure containing these domains, delayed flowering time and reduced the deposition of repressive histone modifications at FLC. RNA-seq and ChIP-seq analyses revealed both shared and specific transcriptomic and epigenetic effects between DVR06- and heat-induced devernalization. Overall, our extensive chemical screening indicated that hydantoin and spiro are key chemical signatures that reduce repressive histone modifications and promote devernalization in plants.

CircZmMED16 delays plant flowering by negatively regulating starch content through its binding to ZmAPS1.

Circular RNAs (circRNAs), a type of head-to-tail closed RNA molecules, have been implicated in various aspects of plant development and stress responses through transcriptome sequencing; however, the precise functional roles of circRNAs in plants remain poorly understood. In this study, we identified a highly expressed circular RNA, circZmMED16, derived from exon 8 of the mediator complex subunit 16 (ZmMED16) across different maize (Zea mays L.) inbred lines using circRNA-seq analysis. This circRNA is predominantly expressed in maize tassels and functions in the cytoplasm. Overexpression of circZmMED16 resulted in increased expression of ZmMED16/AtMED16 and delayed flowering in both maize and Arabidopsis thaliana, compared with that in wild-type plants. In contrast, overexpression of the parent gene ZmMED16 did not alter the flowering time of transgenic plants in Arabidopsis, suggesting that circZmMED16 plays a specific role in regulating flowering, distinct from that of linear ZmMED16. To further understand the mechanisms underlying the regulation of flowering time by circZmMED16, we performed RNA pull-down, dual-luciferase, RNA interference (RNAi), and ribonuclease protection assays (RPA). These results indicate that circZmMED16 interacts with small subunit 1 of ADP-glucose pyrophosphorylase (APS1) mRNA in both maize and Arabidopsis. The knockdown of circZmMED16 increased the expression of ZmAPS1, whereas the overexpression of circZmMED16 led to the downregulation of ZmAPS1 RNA and protein. By affecting ZmAPS1 expression, circZmMED16 reduced ADP-glucose pyrophosphorylase (AGPase) activity and led to delayed flowering. These results revealed a novel regulatory mechanism for circRNAs in flowering time and shed light on their functional and regulatory roles in plants.

Sustainable management of blossom end rot in tomatoes using Lapis Albus 200C and Borax 200C

Objectives: This study explores the efficacy of homoeopathic medicines Lapis Albus 200C and Borax 200C in preventing BER in tomato plants. Material and Methods: Experimental groups included untreated control plants, plants treated with Lapis Albus 200 and plants treated with Borax 200. Treatments were applied bi-weekly, and plant growth, health and yield were monitored over 85 days. Results: Results indicated that both Lapis Albus 200 and Borax 200 significantly improved plant height, yield of healthy tomatoes and reduced flowering time compared to the control group. Group C (Borax 200) exhibited the greatest improvements, with the highest mean stem height of 11 cm (Standard deviation [SD] 0.85), the highest yield of healthy tomatoes at 50% (53 tomatoes) and the shortest flowering time at 49 days (SD 1.22). Group B (Lapis Albus 200) showed a mean stem height of 10 cm (SD 0.77), a yield of 42.45% (25 tomatoes) and a mean flowering time of 50 days (SD 1.41). The control group had a mean stem height of 8 cm (SD 0.81), a yield of 7.54% (8 tomatoes) and a mean flowering time of 55 days (SD 2.68). Conclusion: These findings suggest that homoeopathic treatments may enhance Ca uptake and distribution, improving overall plant health and resilience under stress conditions. The study underscores the potential of Lapis Albus 200C and Borax 200C in managing BER and promoting sustainable tomato production. Future research should focus on the mechanisms through which these remedies influence Ca dynamics and plant stress responses, aiming to integrate homoeopathic treatments into broader agricultural management strategies.

FLOWERING LOCUS C-like mediates low-ambient-temperature-induced late flowering in chrysanthemum.

The flowering time of Chrysanthemum morifolium predominantly depends on day length but is also sensitive to ambient temperature. However, the mechanisms underlying the response of chrysanthemum to ambient temperature are mainly unknown. This study identified a MADS-box transcription factor called CmFLC-like, a representative low ambient temperature-responsive factor induced in chrysanthemum leaves and shoot apical meristems at 15°C. Subsequently, CmFLC-like localizes to the cell nucleus and membrane and functions as a transcriptional repressor. CmFLC-like overexpression made plants more sensitive to low-temperature-induced late flowering, whereas the chimeric activator CmFLC-like-VP64 was less sensitive at 15°C, indicating that CmFLC-like was involved in thermosensory flowering. Transcriptome profiling of CmFLC-like transgenic plants suggested that the potential target genes for low ambient temperature-responsive CmFLC-like regulation are predominantly flowering integrators, MADS-box transcription factors, and AP2 genes. Subsequent examination revealed that the orchestrated repression of CmAFL1 and CmFTL3 by CmFLC-like was mediated by its direct binding to the CArG-box element of their promoters. This study offers novel insights into the molecular mechanisms underlying chrysanthemum flowering and highlights the essential role of CmFLC-like proteins in the thermosensory pathway.