Flowering Genes Research Articles

Chemical genetics in Silene latifolia elucidate regulatory pathways involved in gynoecium development.

Dioecious plants possess diverse sex determination systems and unique mechanisms of reproductive organ development; however, little is known about how sex-linked genes shape the expression of regulatory cascades that lead to developmental differences between sexes. In Silene latifolia, a dioecious plant with stable dimorphism in floral traits, early experiments suggested that female-regulator genes act on the factors that determine the boundaries of the flower whorls. To identify these regulators, we sequenced the transcriptome of male flowers with fully developed gynoecia, induced by rapid demethylation in the parental generation. Eight candidates were found to have a positive role in gynoecium promotion, floral organ size, and whorl boundary, and affect the expression of class B MADS-box flower genes. To complement our transcriptome analysis, we closely examined the floral organs in their native state using field emission environmental scanning electron microscopy, and examined the differences between females and androhermaphrodites in their placenta and ovule organization. Our results reveal the regulatory pathways potentially involved in sex-specific flower development in the classical model of dioecy, S. latifolia. These pathways include previously hypothesized and unknown female-regulator genes that act on the factors that determine the flower boundaries, and a negative regulator of anther development, SUPERMAN-like (SlSUP).

RAD gene family analysis in cotton provides some key genes for flowering and stress tolerance in upland cotton G. hirsutum

BackgroundRADIALIS (RAD), belongs to the MYB gene family and regulates a variety of functions including floral dorsoventral asymmetry in Antirrhinum majus and development of fruit proteins in Solanum lycopersicum. RAD genes contain an SNF2_N superfamily domain. Here, we comprehensively identified 68 RAD genes from six different species including Arabidopsis and five species of cotton.ResultsPhylogenetic analysis classified RAD genes into five groups. Gene structure, protein motifs and conserved amino acid residues indicated that GhRAD genes were highly conserved during the evolutionary process. Chromosomal location information showed that GhRAD genes were distributed unevenly on different chromosomes. Collinearity and selection pressure analysis indicated RAD gene family expansion in G. hirsutum and G. barbadense with purifying selection pressure. Further, various growth and stress related promotor cis-acting elements were observed. Tissue specific expression level indicated that most GhRAD genes were highly expressed in roots and flowers (GhRAD2, GhRAD3, GhRAD4 and GhRAD11). Next, GhRAD genes were regulated by phytohormonal stresses (JA, BL and IAA). Moreover, Ghi-miRN1496, Ghi-miR1440, Ghi-miR2111b, Ghi-miR2950a, Ghi-miR390a, Ghi-miR390b and Ghi-miR7495 were the miRNAs targeting most of GhRAD genes.ConclusionsOur study revealed that RAD genes are evolutionary conserved and might be involved in different developmental processes and hormonal stress response. Data presented in our study could be used as the basis for future studies of RAD genes in cotton.

The transcription factor complex CmAP3-CmPI-CmUIF1 modulates carotenoid metabolism by directly regulating carotenogenic gene CmCCD4a-2 in chrysanthemum.

Carotenoids are one of the most important pigments for the coloring of many plants, fruits, and flowers. Recently, significant progress has been made in carotenoid metabolism. However, our specific understanding of the transcriptional regulation that controls the expression of carotenoid metabolic genes remains extremely limited. Anemone-type chrysanthemums, a special group of chrysanthemum cultivars, contain elongated disc florets in the capitulum that usually differ in color from the ray florets because of their different carotenoid contents. In this study, the carotenoid composition and content of ray and disc florets from the anemone-type chrysanthemum cultivar “Dong Li Fen Gui” were analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS), and the key structural gene CmCCD4a-2, whose differential expression resulted in different carotenoid contents in these two types of florets, was identified. The promoter sequence of CmCCD4a-2 was then used as bait to screen a chrysanthemum flower cDNA library, and the transcription factors (TFs) CmAP3 and CmUIF1 were identified. Y2H, BiFC, and Y3H experiments demonstrated that these two TFs were connected by CmPI to form a CmAP3-CmPI-CmUIF1 TF complex. This TF complex regulated carotenoid metabolism by directly activating the expression of CmCCD4a-2. A large number of target genes regulated directly by the CmAP3-CmPI-CmUIF1 TF complex, including carotenoid biosynthetic genes, flavonoid biosynthetic genes, and flower development-related genes, were identified by DNA-affinity purification sequencing (DAP-seq). This result indicated that the CmAP3-CmPI-CmUIF1 TF complex may participate in multiple processes. These findings expand our knowledge of the transcriptional regulation of carotenoid metabolism in plants and will be helpful for manipulating carotenoid accumulation in chrysanthemum.

TVIR: a comprehensive vegetable information resource database for comparative and functional genomic studies.

Vegetables are an indispensable part of the daily diet of humans. Therefore, it is vital to systematically study the genomic data of vegetables and build a platform for data sharing and analysis. In this study, a comprehensive platform for vegetables with a user-friendly Web interface-The Vegetable Information Resource (TVIR, http://tvir.bio2db.com)-was built based on the genomes of 59 vegetables. TVIR database contains numerous important functional genes, including 5215 auxin genes, 2437 anthocyanin genes, 15 002 flowering genes, 79 830 resistance genes, and 2639 glucosinolate genes of 59 vegetables. In addition, 2597 N6-methyladenosine (m6A) genes were identified, including 513 writers, 1058 erasers, and 1026 readers. A total of 2 101 501 specific clustered regularly interspaced short palindromic repeat (CRISPR) guide sequences and 17 377 miRNAs were detected and deposited in TVIR database. Information on gene synteny, duplication, and orthologs is also provided for 59 vegetable species. TVIR database contains 2 346 850 gene annotations by the Swiss-Prot, TrEMBL, Gene Ontology (GO), Pfam, and Non-redundant (Nr) databases. Synteny, Primer Design, Blast, and JBrowse tools are provided to facilitate users in conducting comparative genomic analyses. This is the first large-scale collection of vegetable genomic data and bioinformatic analysis. All genome and gene sequences, annotations, and bioinformatic results can be easily downloaded from TVIR. Furthermore, transcriptome data of 98 vegetables have been collected and collated, and can be searched by species, tissues, or different growth stages. TVIR is expected to become a key hub for vegetable research globally. The database will be updated with newly assembled vegetable genomes and comparative genomic studies in the future.

Experimental Verification of Inferred Regulatory Interactions of EARLY FLOWERING 3 ( GmELF3-1 ) in Glycine max.

Understanding the roles of evening complex (EC) genes in the circadian clock of plants can inform how diurnal transcriptional loops in the clock gene network function to regulate key physiological and developmental events, including flowering transition. Gene regulatory interactions among soybean's circadian clock and flowering genes were inferred using time-series RNA-seq data and the network inference algorithmic package CausNet. In this study, we seek to clarify the inferred regulatory interactions of the EC gene GmELF3-1. A gene expression analysis using soybean protoplasts as a transient model indicated regulatory roles of GmELF3-1 in expression of selected flowering genes.

Discovery of <i>UPSTREAM OF FLOWERING LOCUS C</i> (<i>UFC</i>) and <i>FLOWERING LOCUS C EXPRESSOR</i> (<i>FLX</i>) in <i>Gladiolus ×hybridus</i>, <i>G. dalenii</i>

The lack of identified flowering genes in ornamental geophytic crops, such as <italic>Gladiolus,</italic> is critical to further genetic research. The <italic>UPSTREAM OF FLOWERING LOCUS C (UFC)</italic> gene is adjacent to <italic>FLOWERING LOCUS C (FLC)</italic> which is a floral repressor; <italic>FLC EXPRESSOR (FLX)</italic> upregulates <italic>FRIGIDA</italic> which upregulates <italic>FLC</italic> expression. The purpose of this research was to determine whether two flowering genes exist in <italic>Gladiolus</italic> ×<italic>hybridus</italic> and <italic>G. dalenii</italic>: <italic>UFC</italic> and <italic>FLX</italic>. Seventeen early flowering and commercial cultivars possess the <italic>UFC</italic> gene with four exons in two allelic forms. The sequenced <italic>UFC</italic> gene, when translated into its amino acid sequence and set in pair-alignment to other species, has &lt; 57% in amino acid identity to <italic>Musa acuminata</italic>. The <italic>FLX</italic> gene in gladiolus has 3/5 (60%) exons in common with <italic>Ananas comosus</italic>; pair-alignment of the exons has ~65% identity of <italic>FLX</italic> to <italic>A. comosus</italic>. The <italic>UFC</italic> protein consists of a conserved domain, <italic>DUF966</italic>, which is higher in identity (86%) and pair-alignment with <italic>Elaeis guineensis</italic>. The two newly-discovered genes in gladiolus, <italic>UFC</italic> and <italic>FLX</italic>, provide insight into the flowering mechanism, flowering pathway genes, and vernalization response.

Flowering process in soybean under water deficit conditions: A review on genetic aspects.

Soybean is a key crop in many countries, being used from human food to the animal industry due to its nutritional properties. Financially, the grain chain moves large sums of money into the economy of producing countries. However, like other agricultural commodities around the world, it can have its final yield seriously compromised by abiotic environmental stressors, like drought. As flowers imply in pods and in grains inside it to minimize damages caused by water restriction, researchers have focused on understanding flowering-process related genes and their interactions. Here a review dedicated to the soybean flowering process and gene network involved in it is presented, describing gene interactions and how genes act in this complex mechanism, also ruled by environmental triggers such as day-light and circadian cycle. The objective was to gather information and insights on the soybean flowering process, aiming to provide knowledge useful to assist in the development of drought-tolerant soybean lines, minimizing losses due to delays or anticipation of flowering and, consequently, restraining financial and productivity losses.

Flower development and sex determination in horticultural crops

Horticultural crops are extremely valuable due to their high nutritional value, and fruits, in particular, provide indispensable vitamins and minerals. Fruit yield of edible crops is closely related to the number of flowers, which are often unisexual. The mechanism of sex differentiation in plants with unisexuality is complex, and research investigating this mechanism is in great demand. Sex determinants were first discovered in <italic>Cucurbitaceae</italic> (e.g., cucumber, melon, watermelon), and in recent years, with the rapid development of deep sequencing technologies and genomics, they have also been deciphered in some dioecious plants (e.g., persimmon, kiwifruit, asparagus). This has deepened our understanding of the evolution and diversification of sexual reproductive systems. This review summarizes recent research investigating flower sex-determination genes and their working networks, focusing on horticultural crops. Perspectives on future research in flower sex differentiation are also discussed.

Transcriptomic and physiological analysis reveals interplay between salicylic acid and drought stress in citrus tree floral initiation.

Salicylic acid (SA) and drought stress promote more flowering in sweet orange. The physiological response and molecular mechanism underlying stress-induced floral initiation were discovered by transcriptome profiling. Numerous flowering-regulated genes were identified, and ectopically expressed CsLIP2A promotes early flowering in Arabidopsis. Floral initiation is a critical developmental mechanism associated with external factors, and citrus flowering is mainly regulated by drought stress. However, little is known about the intricate regulatory network involved in stress-induced flowering in citrus. To understand the molecular mechanism of floral initiation in citrus, flower induction was performed on potted Citrus sinensis trees under the combined treatment of salicylic acid (SA) and drought (DR). Physiological analysis revealed that SA treatment significantly normalized the drastic effect of drought stress by increasing antioxidant enzyme activities (SOD, POD, and CAT), relative leaf water content, total chlorophyll, and proline contents and promoting more flowering than drought treatment. Analysis of transcriptome changes in leaves from different treatments showed that 1135, 2728 and 957 differentially expressed genes (DEGs) were revealed in response to DR, SD (SA + DR), and SA (SA + well water) treatments in comparison with the well watered plants, respectively. A total of 2415, 2318 and 1933 DEGs were expressed in DR, SD, and SA in comparison with water recovery, respectively. Some key flowering genes were more highly expressed in SA-treated drought plants than in DR-treated plants. GO enrichment revealed that SA treatment enhances the regulation and growth of meristem activity under drought conditions, but no such a pathway was found to be highly enriched in the control. Furthermore, we focused on various hormones, sugars, starch metabolism, and biosynthesis-related genes. The KEGG analysis demonstrated that DEGs enriched in starch sucrose metabolism and hormonal signal transduction pathways probably account for stress-induced floral initiation in citrus. In addition, a citrus LIPOYLTRANSFERSAE 2A homologous (LIP2A) gene was upregulated by SD treatment. Ectopic expression of CsLIP2A exhibited early flowering in transgenic Arabidopsis. Taken together, this study provides new insight that contributes to citrus tree floral initiation under the SA-drought scenario as well as an excellent reference for stress-induced floral initiation in woody trees.

The Responses of Physiological Characteristics and Flowering Related Gene to the Different Water Stress Levels of Red-Flesh Pummelo Cultivars (Citrus grandis (L.) Osbeck) Own-Rooted by Air Layering Propagation under Two Growing Conditions

One of the major problems in the fruit production of citrus, including pummelo (Citrus grandis) is controlling flowering induction. Water stress is known to be related to flowering induction via physiological responses related to the flowering gene. However, reports on the mechanisms underlying floral induction by water stress in pummelo are limited. Thus, this study aimed to determine the physiological characteristics and the expression of genes related to flowering induction, CiFT (Citrus Flowering locus T), in pummelo at different levels of water stress. Experiments were conducted under two growing conditions: field and container conditions, each using a 2 × 5 factorial experiment in a randomized complete block. Factor A consisted of two red-flesh pummelo cultivars while factor B consisted of five levels of water stress based on the leaf rolling index. Among the seven characteristics studied, only the data of total nitrogen, CiFT, and flower number were combined for analysis due to their results in a homogeneity test. Although a consistent tendency was not observed for the interaction among environments, genotypes, and water stress levels of all characteristics, ‘KKU-105’ grew more flowers under higher water stress conditions (225 flowers). This result may imply that decreases in total nitrogen (1.48%), stomatal conductance (50.53 m−2s−1), chlorophyll fluorescence (0.30 Fv/Fm), and upregulation of CiFT mRNA level (13.95) may induce flowering in the pummelo cultivar ‘KKU-105’.

Identification of Co-Expressed Genes Related to Theacrine Synthesis in Tea Flowers at Different Developmental Stages.

Jiaocheng kucha is the first reported tea germplasm resource which contains theacrine founded in Fujian Province. Currently, the anabolic mechanism of theacrine within tea leaves is clear, but there are few studies focused on its flowers. In order to further explore the mechanism of theacrine synthesis and related genes in flowers, current study applied Jiaocheng kucha flowers (JC) as test materials and Fuding Dabaicha flowers (FD) as control materials to make transcriptome sequencing, and determination of purine alkaloid content in three different developmental periods (flower bud stage, whitening stage and full opening stage). The results showed that the flower in all stages of JC contained theacrine. The theacrine in the flower bud stage was significantly higher than in the other stages. The differentially expressed genes (DEGs) at three different developmental stages were screened from the transcriptome data, and were in a total of 5642, 8640 and 8465. These DEGs related to the synthesis of theacrine were primarily annotated to the pathways of purine alkaloids. Among them, the number of DEGs in xanthine synthesis pathway was the largest and upregulated in JC, while it was the smallest in caffeine synthesis pathway and downregulated in JC. Further weighted gene co-expression network (WGCNA) indicated that ADSL (CsTGY03G0002327), ADSL (CsTGY09G0001824) and UAZ (CsTGY06G0002694) may be a hub gene for the regulation of theacrine metabolism in JC. Our results will contribute to the identification of candidate genes related to the synthesis of theacrine in tea flowers, and explore the molecular mechanism of theacrine synthesis in JC at different developmental stages.

Flowering ability and expression of the shLFY (shallot-LFY) gene in several Indonesian shallot (Allium cepa, aggregatum group) varieties

Abstract. Irawan J, Dinarti D, Sudarsono, Maharijaya A. 2021. Flowering ability and expression of the shLFY (shallot-LFY) gene in several Indonesian shallot (Allium cepa, aggregatum group) varieties. Biodiversitas 22: 5468-5474. Indonesian shallots (Allium cepa, Aggregatum group) have different flowering abilities. The direction of seed development in the form of true seed shallot (TSS) makes the study of shallot flowering important to support its breeding program. Flowering genes’ presence and their expression demonstrate their significance in inducing flowering. This study aimed to determine the ability of the shLFY gene expression in four shallots varieties (Bima Brebes, Batu Ijo, Biru Lancor, and Sumenep) and the level of expression in each variety during the formation of flower primordia. The research was arranged in a randomized complete block design (RCBD) with varieties as a single factor, for qRT-PCR relative expression data analysis using ??CT comparative method. The results showed that there were differences in flowering ability and the expression value of the shLFY gene between the tested shallot varieties. These differences also were shown within each variety when the umbels of varying ages were tested. There was a positive correlation between the ability to flower and the shLFY gene expression value. The greater shLFY gene expression will be followed by greater flowering ability. Bima Brebes was the variety with the highest flowering ability (91.66%) and highest shLFY gene expression value between other varieties.

Effects of Exogenous Gibberellic Acid in Huanglongbing-affected Sweet Orange Trees under Florida Conditions – I. Flower Bud Emergence and Flower Formation

Under Florida conditions, sweet orange (Citrus sinensis) affected by Huanglongbing {HLB [Candidatus Liberibacter asiaticus (CLas)]} frequently exhibits irregular flowering patterns, including off-season flowering and prolonged bloom period. Such patterns can increase the opportunity for temporal and spatial proliferation of pathogens that infect flower petals, including the fungal causal agent for postbloom fruit drop (PFD) Colletotrichum acutatum J.H. Simmonds. For the development of strategies to manipulate flowering, the effects of floral inhibitor gibberellic acid (GA3) sprayed monthly at full- and half-strength rates (49 and 25 g·ha−1, or 33 and 17 mg·L−1, respectively) with different regimens, starting from September and ending in November, December, or January, on the pattern of spring bloom were evaluated in field-grown HLB-affected ‘Valencia’ sweet orange at two locations in subsequent February through April for two separate years in this study. To further examine whether GA3 effects on flowering patterns vary in different cultivars, early-maturing ‘Navel’ sweet orange trees receiving no GA3 or full-strength GA3 monthly in September through January were included. Overall, for ‘Valencia’ sweet orange, monthly applications of GA3 at 49 g·ha−1 from September to December not only minimized the incidence of scattered emergence of flower buds and open flowers before the major bloom but also shortened the duration of flowering, compared with the untreated control trees. In addition, exogenous GA3 led to decreased leaf flowering locus t (FT) expression starting in December, as well as reduced expression of its downstream flower genes in buds during later months. When applied monthly from September through January at 49 g·ha−1, similar influences of exogenous GA3 on repressing flower bud formation and compressing bloom period were observed in ‘Navel’ sweet orange. These results suggest that by effectively manipulating flowering in HLB-affected sweet orange trees under the Florida climate conditions, exogenous GA3 may be used to reduce early sporadic flowering and thereby shorten the window of C. acutatum infection that causes loss in fruit production.

DECUSSATE network with flowering genes explains the variable effects of qDTY12.1 to rice yield under drought across genetic backgrounds.

The impact of qDTY12.1 in maintaining yield under drought has not been consistent across genetic backgrounds. We hypothesized that synergism or antagonism with additive-effect peripheral genes across the background genome either enhances or undermines its full potential. By modeling the transcriptional networks across sibling qDTY12.1-introgression lines with contrasting yield under drought (LPB=low-yield penalty; HPB=high-yield penalty), the qDTY12.1-encoded DECUSSATE gene (OsDEC) was revealed as the core of a synergy with other genes in the genetic background. OsDEC is expressed in flag leaves and induced by progressive drought at booting stage in LPB but not in HPB. The unique OsDEC signature in LPB is coordinated with 35 upstream and downstream peripheral genes involved in floral development through the cytokinin signaling pathway. Results support the differential network rewiring effects through genetic coupling-uncoupling between qDTY12.1 and other upstream and downstream peripheral genes across the distinct genetic backgrounds of LPB and HPB. The functional DEC-network in LPB defines a mechanism for early flowering as a means for avoiding the drought-induced depletion of photosynthate needed for reproductive growth. Its impact is likely through the timely establishment of stronger source-sink dynamics that sustains a robust reproductive transition under drought.

Ancestral Flowering Plant Chromosomes and Gene Orders Based on Generalized Adjacencies and Chromosomal Gene Co-Occurrences.

Recurrent whole genome duplication and the ensuing loss of redundant genes-fractionation-complicate efforts to reconstruct the gene orders and chromosomes of the ancestors associated with the nodes of a phylogeny. Loss of genes disrupts the gene adjacencies key to current techniques. With our RACCROCHE pipeline, instead of starting with the inference of short ancestral segments, we suggest delaying the choice of gene adjacencies while we accumulate many more syntenically validated generalized (gapped) adjacencies. We obtain longer ancestral contigs using maximum weight matching (MWM). Similarly, we do not construct chromosomes by successively piecing together contigs into larger segments, but rather compile counts of pairwise contig co-occurrences on the set of extant genomes and use these to cluster the contigs. Chromosome-level contig assemblies for a monoploid genome emerge naturally at each node of the phylogeny and the contigs then can be ordered along the chromosome. Sampling alternative MWM solutions, visualizing heat maps, and applying gap statistics allow us to estimate the number of chromosomes in the reconstruction. We introduce several measures of quality: length of contigs, continuity of contig structure on successive ancestors, coverage of the extant genome by the reconstruction, and rearrangement relations among the inferred chromosomes. The reconstructed ancestors are visualized by painting the ancestral projections on the descendant genomes. We submit genomes drawn from a broad range of monocot orders to our pipeline, confirming the tetraploidization event "tau" in the stem lineage between the alismatids and the lilioids. We show additional applications to the Solanaceae and to four Brassica genomes, producing evidence about the monoploid ancestor in each case.

A role of flowering genes in the tolerance of Arabidopsis thaliana to cucumber mosaic virus.

The genetic basis of plant tolerance to parasites is poorly understood. We have previously shown that tolerance of Arabidopsis thaliana to its pathogen cucumber mosaic virus is achieved through changes in host life‐history traits on infection that result in delaying flowering and reallocating resources from vegetative growth to reproduction. In this system we analyse here genetic determinants of tolerance using a recombinant inbred line family derived from a cross of two accessions with extreme phenotypes. Three major quantitative trait loci for tolerance were identified, which co‐located with three flowering repressor genes, FLC, FRI, and HUA2. The role of these genes in tolerance was further examined in genotypes carrying functional or nonfunctional alleles. Functional alleles of FLC together with FRI and/or HUA2 were required for both tolerance and resource reallocation from growth to reproduction. Analyses of FLC alleles from wild accessions that differentially modulate flowering time showed that they ranked differently for their effects on tolerance and flowering. These results pinpoint a role of FLC in A. thaliana tolerance to cucmber mosaic virus, which is a novel major finding, as FLC has not been recognized previously to be involved in plant defence. Although tolerance is associated with a delay in flowering that allows resource reallocation, our results indicate that FLC regulates tolerance and flowering initiation by different mechanisms. Thus, we open a new avenue of research on the interplay between defence and development in plants.

Differential regulation of two 1-aminocyclopropane-1-carboxylate oxidase (ACO) genes, including the additionally cloned DcACO2, during senescence in carnation flowers

1-Aminocyclopropane-1-carboxylate (ACC) oxidase (ACO) catalyzes the final step of ethylene biosynthesis. ACO proteins are also reportedly encoded by a multigene family. Although the presence of several ACO genes is suggested in carnation (Dianthus caryophyllus L.), DcACO1 is the only ACO gene in which full-length cDNA has been isolated. This study aimed to clone another ACO gene in carnation flowers and investigate changes the expression of the two ACO genes in floral organs during flower senescence. We cloned a homolog of the ACO gene from carnation gynoecium and designated it DcACO2. Transcript levels of DcACO2 were higher in the style and ovary than in the petals at harvest, although DcACO2 transcript levels in these organs increased during flower senescence. The ACO activity in the style was very high at harvest, suggesting that this high activity could be attributed to the translation of the DcACO2 transcript. However, DcACO2 transcript was only detected at very low levels in the petals of senesced flowers. Ethylene and ACC treatments accelerated petal wilting and increased ethylene production of the petals, style, and ovary. In the style and ovary, the DcACO1 transcript level was markedly higher than the DcACO2 transcript level as a result of ethylene and ACC treatments, and DcACO1 transcript levels in the petals were also increased by ethylene and ACC treatments. These results indicate that the expression of DcACO1 and DcACO2 are differently regulated among floral organs during senescence in carnation flowers.

Transcriptional Controls for Early Bolting and Flowering in Angelica sinensis.

The root of the perennial herb Angelica sinensis is a widely used source for traditional Chinese medicines. While the plant thrives in cool-moist regions of western China, early bolting and flowering (EBF) for young plants significantly reduces root quality and yield. Approaches to inhibit EBF by changes in physiology during the vernalization process have been investigated; however, the mechanism for activating EBF is still limited. Here, transcript profiles for bolted and unbolted plants (BP and UBP, respectively) were compared by transcriptomic analysis, expression levels of candidate genes were validated by qRT-PCR, and the accumulations of gibberellins (GA1, GA4, GA8, GA9 and GA20) were also monitored by HPLC-MS/MS. A total of over 72,000 unigenes were detected with ca. 2600 differentially expressed genes (DEGs) observed in the BP compared with UBP. While various signaling pathways participate in flower induction, it is genes associated with floral development and the sucrose pathway that are observed to be coordinated in EBF plants, coherently up- and down-regulating flowering genes that activate and inhibit flowering, respectively. The signature transcripts pattern for the developmental pathways that drive flowering provides insight into the molecular signals that activate plant EBF.

The de novo transcriptome identifies important zinc finger signatures associated with flowering in the orchid Arundina graminifolia

Orchids take years to produce the most precious and expensive flowers. Continuous flowering is a rare characteristic of bamboo orchid (Arundina graminifolia). Therefore, finding genetic regulators of this flowering pattern can set new directions for other orchids. Present study demonstrates transcriptome analysis to identify a number of zinc finger transcription factors (ZF TFs) from five stages of flower development and four tissue types. About 480 DEGs were annotated to the zinc finger category, which may involve multiple signaling pathways for flowering control. The highest number of ZF TFs belonged to CCCH domain, followed by BED and INDETERMINATE. Some important ZF TFs were found to control the flowering genes at transcriptional levels. LATE and B-box ZFs respond to photoperiod and hormone signaling. MAD1 and SUF4 control flowering time through FLC. BZR1 and ELF6 possibly respond to vernalization pathway and HUA1 controls flowering through AGAMOUS pathway. WGCNA-based ZF candidates BBX22 and BBX24 involve circadian and hormonal pathways in association with floral integrators to regulate flowering time in A. graminifolia. Thus, our ZF mining can do a great deal to understand the molecular mechanism of continuous flowering in A. graminifolia.

Crosstalk between flowering and cold tolerance genes in almonds (Amygdalus spp.)

Crosstalk between flowering and cold tolerance genes in almonds (Amygdalus spp.)