Flower development and sexual dimorphism in Vernicia montana

The mu oil tree(Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiation of mu oil tree via morphological and histological analyses of unisexual flowers:(Ⅰ) differentiation of male or female primordia to produce staminate flowers(SFs) or transient hermaphrodite flowers(HFs),and(Ⅱ) complete abortion of stamens in transient HFs to generate pistillate flowers(PFs). A total of 1621 sex-biased genes were identified by comparative transcriptome analysis which exhibited elevated rates of protein evolution than unbiased genes. The female-biased genes were enriched in the production of defense compounds while male-biased genes were focused on the production of viable pollens. Transcriptomebased analysis revealed that the differentially expressed genes(DEGs) between PFs and SFs in phase Ⅰ involved in abscisic acid(ABA), auxin(AUX), cytokinin(CK), ethylene(ET), and gibberellin(GA) biosynthesis and signaling showed higher expression levels in males than in females in general, whereas the DEGs involved in jasmonic acid(JA) and salicylic acid(SA) pathways displayed opposite expression patterns. Moreover,differentially expressed endogenous ABA, AUX, GAs, JA, and SA exhibited consistent biased expression patterns with the DEGs by UPLC-MSbased analysis. Exogenous application of an anti-ethylene plant growth regulator could promote the development of stamens in PFs and generated HFs. Comparative transcriptomic and hormonal analyses of PFs and SFs in phase Ⅱ indicated an increase in ET concentration when abortion of stamens in PFs occurred. This study suggested that phytohormones play key roles in sex dimorphism and ET may determine the development of stamens in PFs of mu oil tree, which provides an insight into plant sex differentiation mechanisms.

Species-specific regulatory pathways of small RNAs play sophisticated roles in flower development in Dimocarpus longan Lour.

Flower development plays vital role in horticultural plants.Post-transcriptional regulation via small RNAs is important for plant flower development.To uncover post-transcriptional regulatory networks during the flower development in Dimocarpus longan Lour.‘Shixia’,an economically important fruit crop in subtropical regions,we collected and analyzed sRNA deep-sequencing datasets and degradome libraries Apart from identifying miRNAs and phased siRNA generating loci(PHAS loci),120 hairpin loci,producing abundant sRNAs,were identified by in-house protocols.Our results suggested that 56 miRNA-target pairs,2221-nt-PHAS loci,and 111 hairpin loci are involved in posttranscriptional gene silencing during longan reproductive development.Lineage-specific or species-specific post-transcriptional regulatory modules have been unveiled,including miR482-PHAS and miRN15.miR482-PHAS might be involved in longan flower development beyond their conserved roles in plant defense,and miRN15 is a novel miRNA likely associated with a hairpin locus(HPL-056)to regulate strigolactone receptor gene DWARF14(D14)and the biogenesis of phasiRNAs from D14.These small RNAs are enriched in flower buds,suggesting they are likely involved in post-transcriptional regulatory networks essential for longan flower development via the strigolactone signaling pathway.

A global view of transcriptome dynamics during flower development in Capsicum annuum L.

An analysis of genome-wide gene expression profiles during floral organ development can provide important clues about the molecular basis of gene functions and developmental processes.In this study,we analyzed the transcriptome data of 36 samples obtained during floral organ development from pepper‘6421’and detected 30016 genes that were expressed in at least one sample.K-means clustering analysis was used to classify the data into 16 clusters based on the similarities between the dynamic expression profiles of genes.Of these,15 clusters exhibited notable up-regulation or down-regulation trends in different developmental stages or tissues of floral organs.We identified transcription factors expressed at the early,medium,and late stages of bud development(F1,F5,F9).Transcription factor families such as AP2-ERF,MADS-box,MYB,bHLH,and NAC showed significant levels of enrichment.In comparison with genes expressed in vegetative tissues at different stages,certain genes were specifically up-regulated during flower development;among these,the number of genes specifically up-regulated during the stamen(Sta10)and bud tetrad development(F4)stages was the highest.Through extensive studies of the ABCDE model of flower development in Arabidopsis,we identified 17 ABCDE model candidate genes in pepper,most of which were up-regulated at specific stages of flower bud development.The expression data provided in this study is the most comprehensive dataset available for pepper to date and will serve as a resource for identifying the functions of many specific genes involved in flower development in pepper and other Solanaceae plants.

Molecular mechanism of lycopene cyclases regulating carotenoids ratio in different branches during tea leaf and flower development

Carotenoids are essential components in tea quality, contributing to leaf color and aroma. However, little information about carotenoids in different tea cultivars and their biosynthesis regulation mechanism during leaf development is known. Here we analyzed carotenoids by HPLC in the buds and leaves of 113 tea cultivars harvested on the same day. By profile clustering, carotenoids were divided into five groups. Same group cultivars displayed divergence in the total content of carotenoids but a similar molar ratio. To figure out the molecular mechanisms of this phenomenon, we further characterized all functional lycopene cyclases, which are the branch point of the carotenoid biosynthesis pathway. Two β-lycopene cyclases(CsLCYB1 and CsLCYB2) and one ε-lycopene cyclase(CsLCYE1) were cloned. Subcellular localization analysis showed that all cloned CsLCYs were localized in plastids. Enzyme activity assays in E. coli indicated both CsLCYBs catalyzed lycopene into β-carotene, and CsLCYE1 produced δ-carotene and ε-carotene. We found CsLCYB1 and CsLCYE1 predominantly expressed in leaf, while CsLCYB2was mainly expressed during flowering stages. Suppression by antisense oligonucleotides reduced CsLCYB1 and CsLCYE1 transcripts and led to reduction of both β,β-branch and β,ε-branch carotenoids in leaf. The expression levels of CsLCYB1 showed a significant positive correlation withβ,β-branch carotenoids in leaf. Our study provides carotenoid profiles of different tea cultivars, which can assist tea producers in selecting cultivars of interest. Meanwhile, we proposed the molecular mechanism of carotenoids reflecting the tenderness of tea plant leaf from a metabolic flux perspective, and suggested lycopene cyclase that could be applied to the breeding of tea varieties with different branch carotenoids.

The BnTFL1–BnGF14nu–BnFD module regulates flower development and plant architecture in Brassica napus

Flower development and plant architecture determine the efficiency of mechanized harvest and seed yield in Brassica napus.Although TERMINAL FLOWER 1(AtTFL1)is a regulator of flower development in Arabidopsis thaliana,the function and regulatory mechanism of TFL1 orthologs in B.napus remains unclear.Six BnTFL1 paralogs in the genome of the B.napus inbred line‘K407’showed steadily increasing expression during vernalization.CRISPR/Cas-induced mutagenesis of up to four BnTFL1 paralogs resulted in early flowering and alteration of plant architecture,whereas seed yield was not altered in BnTFL1 single,double,or triple mutants.Six BnTFL1 paralogs,but not BnaA02.TFL1,showed an additive and conserved effect on regulating flowering time,total and terminal flower number,and plant architecture.BnaA10.TFL1 regulates flower development by interacting with BnaA08.FD through the protein BnaA05.GF14nu,resulting in the transcriptional repression of floral integrator and floral meristem identity genes.These findings about the regulatory network controlling flower development and plant architecture present a promising route to modifying these traits in B.napus.

The IDD Transcription Factors:Their Functions in Plant Development and Environmental Response

INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversity of physiological processes and functions in plant growth and development,including floral transition,plant architecture,seed and root development,and hormone signaling.In this review,we especially summarized the latest knowledge on the functions and working models of IDD members in Arabidopsis,rice,and maize,particularly focusing on their role in the regulatory network of biotic and abiotic environmental responses,such as gravity,temperature,water,and pathogens.Understanding these mechanisms underlying the function of IDD proteins in these processes is important for improving crop yields by manipulating their activity.Overall,the review offers valuable insights into the functions and mechanisms of IDD proteins in plants,providing a foundation for further research and potential applications in agriculture.

Pistillate Flower Development and Stigma Receptivity of Euphorbia pulcherrima

Objective] This study aimed to investigate the relationship between pistil-late flower developmental morphology and stigma receptivity in Euphorbia pulcherri-ma. [Method] One-year-old adult plants of E. pulcherrima cultivar ‘Mil enium’ were used as experimental materials to analyze pistil ate flower development process by macroscopic and scanning electron microscope （SEM） observation. Stigma receptivity was detected with benzidine-hydrogen peroxide method and in vivo pol en germina-tion method. [Result] The pistil ate flower development process of E. pulcherrima was consisted of columnar stigma phase, stigma lobe slightly opening phase, Y-shape stigma lobe phase, inverse V-shaped stigma lobe phase and stigma curling phase. Pistil ate flower development and stigma receptivity of E. pulcherrima exhibit-ed certain correlation. The stigma receptive period lasted from stigma lobe slightly opening phase to inverse V-shaped stigma lobe phase; inverse V-shaped stigma lobe phase was appropriate for pol ination, lasting for 3-5 d, with V-shaped stigma lobe and a large amount of exudates on stigma surface according to SEM obser-vation. Stigma receptivity of E. pulcherrima detected with benzidine-hydrogen perox-ide method was consistent with that detected in vivo pol en germination method. [Conclusion] ln breeding practice, the optimal pol ination period of E. pulcherrima can be determined based on the developmental morphology of pistil ate flower.

Flowering Biology and Fruit Development Characteristics of Apricot Cultivar ‘Kezilang' in Xinjiang

The flowering biology and fruit development characteristics of a Xinjiang apricot （Armeniaca vulgaris Lam） cultivar Kezilang were studied by measuring its flowering phenology, floral organ development, stigma receptivity, pollen quantity, pollen viability, fruit diameter, fruit fresh weight, fruit dry weight and fruit contents, with an attempt to provide a theoretical basis for the cultivation and promotion of Kezilang. The results showed that Kezilang can be popularized as an early-maturing apricot cultivar, as it had high fruit setting rate, large fruit weight, excellent taste, high sugar content and lower titratable acid content in fruit. The dynamic curves of Kezilang fruit diameters in three directions, fruit fresh weight and fruit dry weight were all S-shaped, and the rapid growth stage of dry weight was later than that of other terms. Fruit swelling was due to higher water content of flesh tissue in early stage of the rapid growth periods of fruit. Most sugar in flesh was accumulated at the second rapid growth period of fruit.

Study on the Flower Development of Testtube Plantletsof Orychophragmus violaceus

In this study, testtube plantlets of O.Violaceus were cultured on MS media and treated with low temperature, phytohormones, etc. The following results were obtained: 1. The cold treatment of 5～7℃ for more than 7 days was needed for flower initiation of the testtube plantlets originated from germinated seeds. 2. When cultured on the MS media supplemented with 2mg/L gibberellin (GA3), the testtube plantlets could initiate flowers without cold treatment. 3. When the MS media was supplemented with a reduced amount of NH4NO3, flower initiation of the testtube plantlets could be accelerated. The results of the study on flower development of O.Violaceus may be useful for the production of testtube flowers of this ornamental plant species.

Exploitation of Wild Flowers and the Sustainable Development of Flowers Industry in China

This article introduced the new methods on the research of the wild flowers and plants idioplasmic resources, elaborated the introduction and domestication and exploitation of wild flowers and plants idioplasmatic resources and the sustainable development of flowers and plants industry in China, and put forward some proposals on the existing question and the prospects for the development.

Flower Development and Photoperiodic Control of Flowering in Rice

Floral transition,which is referred to as a plant＇s transition from vegetative stage to reproductive stage,is considered to be a critical developmental switch in higher plants,for a timely flowering is a major factor of reproductive success.Endogenous and environmental cues,such as photoperiod,light quality,plant hormones concentrations and temperature,provide information to the plants whether the environment is favorable for flowering.These cues promote,or prevent,flowering through a complex genetic network,mediated by a careful orchestration of temporal and spatial gene expression.One of such cues is photoperiod.Rice（Oryza sativa L.） serves as a powerful model species for the understanding of flowering in higher plants,including flower development and photoperiodic control of flowering.In this review,we overviewed and discussed the flower development and its model.We also overviewed the photoperiodic pathways in rice flowering control,and summarized the pathways at molecular level.

Comparative microsporogenesis and flower development in Eucalyptus urophylla×E.grandis

Microsporogenesis and flower development in Eucalyptus urophylla × E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was normal, cytokinesis during meiosis of pollen mother cells occurred simultaneously, with strong asynchronism observed in the two different lengths of stamens in a flower bud. In a single flower, the developmental period of microsporogenesis in anthers on the longer stamens was always ahead of those on the shorter stamens. Flower development was also asynchronous at different locations on a branch. Flower buds on the upper side of the branch were larger in diameter than those on the lower side. In addition, a correlation was observed between microsporogenesis development and flower bud diameter growth. The pachy- tene stage was first observed when the diameter of the flower buds increased to 3.0 mm, and the majority of the meiotic stages were observed when bud diameters ranged from 3.5 to 5.0 mm. This study showed that the developmental stages of microsporogenesis in Eucalyptus urophylla × E. grandis could be distinguished readily, which may be applicable to future breeding studies.

Transcriptomic profiling of watermelon(Citrullus lanatus) provides insights into male flowers development

Watermelon(Citrullus lanatus(Thunb.) Matsum. & Nakai) is an important cucurbit crop grown worldwide. Watermelon fruit quality, fertility, and seed-setting rate are closely related to male flower development. In this study, the different developmental stages of flower buds of the watermelon cultivar ’Xinteda Zhengkang 9’ were distinguished by cytological observation, and transcriptome sequencing analysis was performed subsequently. Acetocarmine staining of anthers was performed and the longitudinal and transverse diameters of the unopened male flower buds were measured. Cytological observations of anthers at different developmental stages showed that the anther grew from the tetrad to the mature stage, and the longitudinal and transverse diameters of the flower buds increased. The length of the male flower buds also changed significantly during development. Transcriptome sequencing analysis at four periods, the tetrad(A group), mononuclear(B group), dikaryophase(C group), and mature stages(D group). A total of 16 288 differentially expressed genes(DEGs) were detected in the four stages, with the prolongation of developmental stages, the number of DEGs increased gradually in the comparison groups, there was 2 014, 3 259, 4 628, 1 490, 3 495 and 1 132 DEGs revealed in six comparison groups(A-vs.-B, A-vs.-C, A-vs.-D, B-vs.-C, B-vs.-D, and C-vs.-D), respectively. Gene Ontology(GO) and KEGG enrichment analysis showed that the DEGs were mainly enriched in cellular component and starch and sucrose metabolism, phenylpropanoid biosynthesis and pentose sugar, etc. Finally, we completely screened 59 DEGs in the six comparison groups, interestingly, we found one pollen-specific protein(Cla001608) that was significantly down-regulated(the value of log2 Fold Change up to 17.32), which indicated that it may play an important role in the development of male flowers. This work provides insight into the molecular basis of the developmental stages of male flowers in watermelon and may aid in dominant cross breeding.

Innovation and Prospects of Development of Flower Industry——A Case Study of Guangxi

In order to find out the situation of the innovation and development of the flower industry in Guangxi,the paper analyzed the development status of flower industry in Guangxi,summarized the achievements and experience of technological innovation,and the prominent problems in the development of flower industry.On the basis of the analysis,it came up with some recommendations for the development of the flower industry in Guangxi,so as to provide theoretical reference for the development of the flower industry in Guangxi.

Transcription Co-repressors in Flower Development

Transcription co-repressors are negative regulators of gene expression. Since they do not possess a DNA-binding motif, their ability to repress gene expression depends on their association with other DNA-binding transcription factors. One well characterized transcription co-repressor is the yeast Tupl. Although unable to bind DNA by itself, the Tupl co-repressor is recruited by different DNA-binding transcription factors to repress pathway-spocific gene expression. Recent isolations of two Arabidopsis genes, LEUNIG (LUG) and SEUSS ( SEU), suggest that similar types of co-re-pressors are involved in the transcription repression of floral homeotic genes during flower develop-ment. This review will summarize these findings, speculate on mechanisms, and discuss future di-rections.

The Study of Some Problems of Yunnan Flower Industry Development

A few problems exist in flower industry developmentin Yunnan province.The key problem is flower production with sell set in system unqualified,product quality problem;wrong model in specification of quality in product,undeveloped and developed technology of quality standard system hasn’t been used.To change present condition, combining local presentcondition, we can enhance the macroscopic managementand put forward to peasant the policy suggestion to guide the development of Yunnan province flower industry.

Ectopic expression of OsNF-YA8,an endosperm-specific nuclear factor Y transcription-factor gene,causes vegetative and reproductive development defects in rice

Nuclear factor Y(NF-Y),a group of conserved transcription-factor complexes that consist of NF-YA,B,and C subunits,is essential for developmental regulation and for responses to environmental changes in eukaryotes.We previously found that some NF-Y genes,such as OsNF-YA8,were expressed specifically in the endosperm of rice.In the present study,overexpression of OsNF-YA8 in rice resulted in reduced plant height due to suppressed cell elongation in internodes.Gibberellin(GA)biosynthetic genes,including OsCPS1,OsGA20ox1,and OsGA20ox2,were down-regulated.OsNF-YA8 bound to the promoters of these genes to repress their expression.Endogenous GA content was decreased in OsNF-YA8 overexpressors,whose dwarf phenotype could be partially rescued by exogenous GA treatment.The findings suggested that ectopic expression of OsNF-YA8 causes defective GA biosynthesis in vegetative stage.Heading date in OsNF-YA8 overexpressors was delayed,especially under short-day conditions.OsNFYA8 bound to the promoter of Heading Date 3a(Hd3a),the florigen gene in rice,to negatively regulate flowering.Either ectopic activation or knockout of OsNF-YA8 impaired seed development,as indicated by reduced seed size and increased grain chalkiness.These results suggest that ectopic expression of the endosperm-specific OsNF-YA8 in rice disrupts both vegetative and reproductive development.

Characterization and Genetic Analysis of a Novel Mutant mst of Rice Defective in Flower Development

A spontaneous mutant with multiple stigmas （msf） was found in an indica rice line 466. The mst mutant exhibits normal at the vegetative development stage and produces normal inflorescence structures. The difference between the mutant and the wild type was observed when the stamen primordium began to develop. In the mst florets, palea and lemma opened, Iodicules were homeotically transformed into palea/lemma-like structures, and stamens were homeotically transformed into carpel-like structures. It looked like multiple stigmas being full of the whole floret. The phenotypic changes of rest were very similar to that of B-like mutant spwl. Compared with other mutants with pistillate morphologies, the severe mstflorets showed that the inner three floral organs were completely changed into palea/lemma-like structures. Moreover, the mutant was female sterile. Occasionally, with the changing environment, one or two stamens were fertile. Genetic analysis indicated that the mutant traits were controlled by a single recessive gene.

Biological Features of Flowering and Development of Male Gametophyte in Anthurium andreanum

The aim of this study is to follow each development stage of inflorescence in order to understand the biological feature of flowering and the development of male gametophyte in Anthurium andreanum “Arizona' and to try to find the optimum conditions for its pollination. The methods of dissection and paraffin section were adopted to examine the structural characteristics of anthurium’s tiny floret and the development of the microspore. All the florets of the anthurium arrange on the rhachis helically sub- tended by a colorful bract. Each tiny floret has one gynoecium, four tepals and four stamina. The bract and the florets show different colors during the whole blooming period. The ovary is bicarpellary and has two locules, each of which has one anatropous ovule. The placenta is of a central placentation type. The stylar canal cells not only can produce the secretory mucilage but also can release their own cytoplasm caused by their self-disintegration before the pistil reaches its maturity. The wall of the anther is composed of four layers: epidermis, endothecium, middle layer and tapetum. The tapetal cells and the middle layers’ cells degenerated completely dur- ing meiosis of microsporocytes. The pollen grains were 2-celled at the time of anther dehiscence. Early morning, when the inflores- cences stay at their fifth development stage, is the optimum opportunity for pistil to get pollen grains. The pollen-collection should be done at the end of the seventh stage.

Effects of H_2O_2 and NO on Flower Development and AP1 Gene Expression of Off-season Longan

[Objective] This study aimed to investigate the effects of H2O2 and NO on flower development and 4P1 gene expression of off-season longan. [Meth-od ]Nine-year-old off-season Chuliang longan was sprayed with enhancers and blockers of H2O2 and NO to analyze dynamic changes of flower development and API expression. [ Result] The expression level of API gene in off-season longan was improved during flower development. SNP and MV treatments up-regulated the expression level of API gene in leaves and terminal buds to varying degrees during lateral primordium formation. Especially, SNP treatment exhibited the most remark-able effect. DMTU treatment significantly inhibited the expression of AP1 gene in leaves and terminal buds during lateral primordium formation. L-NNA treatment slightly inhibited the expression of API gene in leaves and exerted no significant effect on expression of AP1 gene in terminal buds. [ Conclusion] It can be specu-lated that the enhancement of NO and H2O2 signals is conducive to flower development of off-season longan, while blocking H2O2 signals may inhibit flower develop-ment of off-season longan.