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At least 19 recordsLinked to original sources
PubMed2026

The Jumonji C domain-containing proteins GmJMJ19 and GmJMJ20 link florigen signaling with epigenetic regulation of photoperiodic flowering and post-flowering plant height in soybean.

Soybean (Glycine max) is a photoperiod-sensitive legume whose latitudinal adaptation depends on the precise control of flowering time and plant height. Histone demethylases of the JmjC domain-containing (JMJ) protein family have been implicated in these processes across plant species, but their specific roles in soybean remain largely unexplored. Here, we identify soybean GmJMJ19 and GmJMJ20, two closely related JMJD5/KDM8 orthologs, as master epigenetic regulators that coordinately control both photoperiodic flowering and post-flowering plant height. Both genes exhibit intrinsic, rhythmic expression peaking at ZT12, and their encoded proteins physically interact with the florigen proteins FT2a and FT5a. Loss-of-function mutants display delayed flowering under long days (LDs) and increased plant height under both LDs and short days (SDs), whereas overexpression phenocopies the mutant flowering phenotype, indicating revealing a critical dosage requirement for proper function. Mechanistically, GmJMJ19 and GmJMJ20 are recruited by the FT/FD transcriptional complex to directly activate AP1a and AP1c expression through chromatin modulation. Population genomic analyses reveal distinct selection signatures: GmJMJ19 underwent sustained directional selection during cultivation, whereas GmJMJ20 experienced an early domestication sweep with limited subsequent change. Haplotype analysis identifies coordinated latitudinal clines, with the JMJ19H1/JMJ20H1 combination predominating at high latitudes to promote early flowering and limit height, while JMJ19H2/JMJ20H2 and wild JMJ19H3/JMJ20H3 alleles prevail at low latitudes, conferring later flowering and increased height. Collectively, our findings establish GmJMJ19 and GmJMJ20 as central chromatin regulators linking florigen signaling to downstream target expression and provide valuable allelic resources for breeding regionally adapted soybean varieties across a wide range of latitudinal environments.

Histone modulation↗
PubMed1991

A flourishing time for flower development. Workshop on Flower Development, sponsored by Fundación Juan March, Madrid, Spain, March 11-13, 1991.

Molecular genetics has recently erupted in the field of flower development, an area of research traditionally cultivated by plant physiologists. The isolation and molecular characterization of seven homeotic genes (four in Antirrhinum majus and three in Arabidopsis thaliana) that control both floral organogenesis and the transition from inflorescences to floral meristems is leading to major breakthroughs in the understanding of the mechanisms governing flower development. This has already had a great impact among plant physiologists, who are incorporating mutant analysis into studies of floral induction and flower development. We are still missing data about the nature of the pollen product of the S-locus in self-incompatibility systems, although current experimental approaches might provide this information in the near future. Gene technology appears to have a high potential in hybrid seed production through the construction of male sterile plants as well as of plants able to restore fertility. The study of genes regulating pigment formation in flowers continues to provide interesting data on gene expression in plants, in which phenomena such as co-suppression and methylation seem to play an important role. Altogether, one can predict that very exciting times are coming in the field of flower development.

Gene Expression Regulation↗
PubMed2026

Dissecting genetic architecture and improving machine learning‑based genomic prediction of flowering time in Osmanthus fragrans by integrating structural variants.

Sweet osmanthus (Osmanthus fragrans), a traditional ornamental plant in China, exhibits substantial variation in autumn flowering time, which significantly affects landscape application and cultivation efficiency. Here, we performed a genome-wide association study on 127 resequenced accessions classified into early, intermediate, and late flowering types, using a set of 2,325,410 single-nucleotide polymorphisms (SNPs) and 246,824 structural variants (SVs). By integrating SNP/insertion and deletion (Indel) and SV data with weighted gene co-expression network analysis, machine learning, and genomic prediction, we dissected the genetic architecture of flowering time. We identified 24 associated SNP/Indels and six SVs, mapping to 30 candidate genes, including known flowering regulators FLK, LOS1, Y14, MIF2, and GID1B. These genes showed tissue-specific expression, with some responding to low temperature. The two hub genes, GUX1 and LYG027904, were located within modules of the co-expression network associated with low-temperature treatment. Haplotype analysis revealed a specific three-SNP haplotype associated with late flowering and linked to LOS1, and epistatic interactions among combined genotypes contributed to phenotypic variation. Notably, integrating SVs with SNP/Indels improved genomic prediction accuracy; the gradient boosting decision tree model outperformed other machine learning algorithms, achieving a mean accuracy of 0.859 and an AUC > 0.8 (where AUC is area under receiver operating characteristic curve) for all flowering types. These findings provide insights into the genetic mechanisms underlying flowering time variation in O. fragrans, offer candidate genes and haplotypes for molecular breeding, and highlight the value of integrating SVs with machine learning for genomic prediction in woody ornamentals.

Machine Learning↗
PubMed1991

Indigenous multiresistant bacteria from flowers in hospital and nonhospital environments.

The microbial flora of 60 vase water samples from cut flowers obtained from several environments, including a hospital, were examined in this study. Forty-one different bacterial species were identified, including 12 species of Pseudomonas. The mean total aerobic bacterial count per 500 ml of vase water was 4.5 x 10(8) organisms, and high levels of antibiotic resistance were found. To ascertain the origin of the bacteria found on the flowers as well as their growth patterns, natural cut flowers were compared with sterilized cut flowers in tap water over time. Although the density of organisms was similar, the flora in vase water of sterilized flowers consisted almost entirely of aerobic spore formers while mixed flora of gram-negative bacteria, staphylococci, aerobic spore formers, and fungi were isolated from natural flowers. Our results indicate that the multiply-resistant microbial flora found in vase water is indigenous to flowers, rather than originating from the environment in which they are placed, and that such water is a reservoir of large numbers of multiresistant organisms.

Bacteria↗
PubMed2026

Human m6A demethylase FTO modulates the flowering time of tomato plants under low-temperature stress.

N6-methyladenosine (m6A) RNA modification plays an important role in plant development and environmental stress responses. However, whether m6A demethylation modulates flowering under low-temperature (LT) stress in tomatoes remains unclear. Here, we investigated whether ectopic expression of FTO, a well-characterized human m6A demethylase, influences flowering and post-transcriptional behaviour in tomato (Solanum lycopersicum) under LT conditions. Flowering of transgenic tomato plants expressing FTO was analyzed under LT and normal conditions (NC), and the impacts of FTO on transcripts-specific m6A level, mRNA stability and splicing efficiency of flowering-related genes were evaluated using RT-qPCR, LC-MS/MS, m6A-IP-qPCR, and RNA decay and splicing analyses. FTO-expressing plants exhibited accelerated flowering specifically under LT, whereas no significant differences were observed under normal growth conditions. This phenotype was accompanied by increased expression of positive floral regulators (SlMC, SlFCA, and SlJ2) and decreased expression of negative regulators (SlSVP, SlSP, and SlTMF) under LT conditions. Notably, these expression changes were associated with altered mRNA stability, with positive regulators showing increased stability and negative regulators showing reduced stability under LT conditions. m6A-IP-qPCR analysis indicated reduced m6A enrichment in these selected transcripts in FTO-expressing plants. In addition to effects on mRNA stability, FTO expression was associated with changes in the splicing efficiency of SlMC transcripts. Collectively, our findings indicate that human FTO functions as an mRNA m6A demethylase in tomatoes and is associated with altered RNA regulatory processes under LT conditions. These findings suggest that m6A-mediated post-transcriptional regulation contributes to stress-induced flowering plasticity under LT conditions, rather than direct activation of canonical flowering pathways.

Abiotic stress↗
PubMed1992

[Flower bud differentiation and development of opium poppy (Papaver somniferum L.) II. Effects of daylength and temperature].

We investigated the effect of daylength (from 9 to 15 hours) and cultivation temperature (from about 13 to 25 degrees C) on flower bud differentiation of three strains of Papaver somniferum L. cv. Ikkanshu, which have been cultivated in Nayoro (Hokkaido), Tsukuba (Central Honshu) and Nagasaki (Kyushu) for the last a few decades. 1. The experiment on the effect of daylength on flowering revealed that the longer the photoperiod was, the earlier flowering occurred. 2. Flower bud differentiation was observed at temperatures of 20 degrees C or less but never at 25 degrees C, and it was more quickly induced at lower temperatures. Furthermore, we also found that the optimum temperature for flower bud development following differentiation was 20 degrees C. From these findings, we reached the conclusion that this species has thermosensitivity. 3. Flower bud differentiation clearly occurred later in the Nayoro strain than in the Nagasaki strain or the Tsukuba strain. This seems to indicate that the Nayoro strain is a different ecological type from other strains. 4. When we compared the size and dry weight of the capsules, which are known to be closely related to opium yield, the capsules of the Nagasaki and Tsukuba strains were considerably smaller and lighter than those of the Nayoro strain. This is attributable to the fact that flower bud differentiation occurred at an early stage before the achievement of sufficient vegetative growth in the Nagasaki and Tsukuba strains.

Light↗
PubMed2026

Pleiotropic mutation in a tendril TCP gene underlies the yield-enhancing multiple-flowering trait in summer squash (Cucurbita pepo).

Crop yield is a focal point in plant breeding. Regulation of lateral budding through apical dominance was a central target of crop domestication, directly affecting crop production. The young fruits of Cucurbita pepo, summer squash, are produced on plants characterized by apical dominance and differentiation of a single flower bud per leaf axil. A single recessive mutation, mf, results in differentiation of more than one flower per leaf axil, thereby directly increasing production because of the continual day-to-day harvest of the summer squash crop. Positional cloning of the Cucurbita pepo mf (Cpmf) gene denoted a frameshift mutation in a TCP transcription factor, Cp4.1LG13g07780, as causative for the increase in axillary flowering. Cpmf is an ortholog of a tendril-development TCP gene in other cucurbits, and likewise, the recessive allele of Cpmf is associated with distorted tendril development. Gene function is context dependent, and we propose that multiple flowering is a unique pleiotropic attribute of mutation in a tendril-development gene of C. pepo. Characterization of a C. pepo collection confirmed a significant association of the Cpmf mutation with multiple flowering and showed that the mutant allele is absent in ancestral C. pepo and one of its two cultivated subspecies. The beneficial mutation occurred and was selected after the domestication of the other subspecies, during its cultivation for young fruit production. We demonstrate the discovery of a causative yield-increasing sequence variant and its practical utilization in breeding. Our findings provide a molecular target for creation of high-yielding, multiple-flowering summer squash cultivars through marker-assisted breeding or precise genome editing.

Cucurbita↗
PubMed1990

Deficiens, a homeotic gene involved in the control of flower morphogenesis in Antirrhinum majus: the protein shows homology to transcription factors.

Deficiens (defA+) is a homeotic gene involved in the genetic control of Antirrhinum majus flower development. Mutation of this gene (defA-1) causes homeotic transformation of petals into sepals and of stamina into carpels in flowers displaying the 'globifera' phenotype, as shown by cross sections and scanning electronmicroscopy of developing flowers. A cDNA derived from the wild type defA+ gene has been cloned by differential screening of a subtracted 'flower specific' cDNA library. The identity of this cDNA with the defA+ gene product has been confirmed by utilizing the somatic and germinal instability of defA-1 mutants. According to Northern blot analyses the defA+ gene is expressed in flowers but not in leaves, and its expression is nearly constant during all stages of flower development. The 1.1 kb long mRNA has a 681 bp long open reading frame that can code for a putative protein of 227 amino acids (mol. wt 26.2 kd). At its N-terminus the DEF A protein reveals homology to a conserved domain of the regulatory proteins SRF (activating c-fos) in mammals and GRM/PRTF (regulating mating type) in yeast. We discuss the structure and the possible function of the DEF A protein in the control of floral organogenesis.

Amino Acid Sequence↗
PubMed1991

A genetic and physiological analysis of late flowering mutants in Arabidopsis thaliana.

Monogenic mutants of the early ecotype Landsberg erecta were selected on the basis of late flowering under long day (LD) conditions after treatment with ethyl methanesulphonate or irradiation. In addition to later flowering the number of rosette and cauline leaves is proportionally higher in all mutants, although the correlation coefficient between the two parameters is not the same for all genotypes. Forty-two independently induced mutants were found to represent mutations at 11 loci. The mutations were either recessive, intermediate (co locus) or almost completely dominant (fwa locus). The loci are located at distinct positions on four of the five Arabidopsis chromosomes. Recombinants carrying mutations at different loci flower later than or as late as the later parental mutant. This distinction led to the assignment of eight of the loci to three epistatic groups. In wild type, vernalization promotes flowering to a small extent. For mutants at the loci fca, fve, fy and fpa, vernalization has a large effect both under LD and short day (SD) conditions, whereas co, gi, fd and fwa mutants are almost completely insensitive to this treatment. SD induces later flowering except for mutants at the co and gi loci, which flower with the same number of leaves under LD and SD conditions. This differential response of the mutants to environmental factors and their subdivision into epistatic groups is discussed in relation to a causal model for floral initiation in Arabidopsis thaliana.

Alleles↗
PubMed1991

A genetic and molecular model for flower development in Arabidopsis thaliana.

Cells in developing organisms do not only differentiate, they differentiate in defined patterns. A striking example is the differentiation of flowers, which in most plant families consist of four types of organs: sepals, petals, stamens and carpels, each composed of characteristic cell types. In the families of flowering plants in which these organs occur, they are patterned with the sepals in the outermost whorl or whorls of the flower, with the petals next closest to the center, the stamens even closer to the center, and the carpels central. In each species of flowering plant the disposition and number (or range of numbers) of these organs is also specified, and the floral 'formula' is repeated in each of the flowers on each individual plant of the species. We do not know how cells in developing plants determine their position, and in response to this determination differentiate to the cell types appropriate for that position. While there have been a number of speculative proposals for the mechanism of organ specification in flowers (Goethe, 1790; Goebel, 1900; Heslop-Harrison, 1964; Green, 1988), recent genetic evidence is inconsistent with all of them, at least in the forms in which they were originally presented (Bowman et al. 1989; Meyerowitz et al. 1989). We describe here a preliminary model, based on experiments with Arabidopsis thaliana. The model is by and large consistent with existing evidence, and has predicted the results of a number of genetic and molecular experiments that have been recently performed.

Models, Chemical↗
PubMed2025

Integrated transcriptomic, transcriptional factors, and protein interaction reveal the regulatory mechanisms of flowering time in rice (Oryza sativa L.).

Appropriate flowering time is important for rice regional adaptation and optimum rice production, but little is known about the omics of heading date in rice. Here, we studied omics including transcriptome, proteome and transcriptional factors to identify regulatory genes related to flowering time. A total of 1402 differentially expressed genes (DEGs, 721 up-regulated and 681 down-regulated) were detected in wild and mutant. These transcripts are classified according to biological processes, cellular components, and molecular functions. Among these differentially expressed genes, many transcription factor genes demonstrated multiple regulatory pathways involved in flowering time. Gene expression analysis showed that Os03g0122600 (OsMADS50), Os08g0105000 (Ehd3), Os06g0275000 (Hd1) were expressed higher and Os06g0199500 (OsHAL3), Os06g0498800 (OsMFT1), Os08g0105000 (Ehd3), Os06g0157700 (Hd3a), and Os02g0731700 (Ghd2), were expressed lower in wild compared to mutant, which are the key genes that regulate the flowering in rice. In addition, Ghd7 interacted with Os10g30860 and Os12g08260 using yeast two-hybrid assay. We identified 28 potential Ghd7 transcriptional regulators using the transcription factor-centered yeast one hybrid (TF-Centered Y1H) assay. Taken together, this study developed a new set of genomic resources to identify and characterize genes, proteins, and motifs associated with flowering time.

Oryza↗
PubMed1990

Promoter analysis of the chalcone synthase (chsA) gene of Petunia hybrida: a 67 bp promoter region directs flower-specific expression.

In order to scan the 5' flanking region of the chalcone synthase (chs A) gene for regulatory sequences involved in directing flower-specific and UV-inducible expression, a chimaeric gene was constructed containing the chs A promoter of Petunia hybrida (V30), the chloramphenicol acetyl transferase (cat) structural sequence as a reporter gene and the chs A terminator region of Petunia hybrida (V30). This chimaeric gene and 5' end deletions thereof were introduced into Petunia plants with the help of Ti plasmid-derived plant vectors and CAT activity was measured. A 220 bp chs A promoter fragment contains cis-acting elements conferring flower-specific and UV-inducible expression. A promoter fragment from -67 to +1, although at a low level, was still able to direct flower-specific expression but could not drive UV-inducible expression in transgenic Petunia seedlings. Molecular analysis of binding of flower nuclear proteins to chs A promoter fragments by gel retardation assays showed strong specific binding to the sequences from -142 to +81. Promoter sequence comparison of chs genes from other plant species, combined with the deletion analysis and gel retardation assays, strongly suggests the involvement of the TACPyAT repeats (-59 and -52) in the regulation of organ-specificity of the chs A gene in Petunia hybrida. We also describe an in vitro organ-specific transient expression system, in which flower or purple callus protoplasts are used, that enables us to pre-screen organ-specific expression of a chimaeric reporter gene.

Acyltransferases↗