Cloning and Analysis of the cDNA Sequence of XTH Gene from Chrysanthemum morifolium Petal

[Objective] This study aimed to investigate the structural character of xy- Ioglucan endotransglycosylase/hydrolase （XTH） gene in ethylene-insensitive feverfew. [Method] The total RNA was extracted from Chrysanthemum rnorifolium petal using Trizol reagent, and the cDNA fragment of XTH gene was cloned by RT-PCR and T/A cloning. [Result] The sequencing result showed that the cloned cDNA sequence was 911 bp. It was predicted to encode a polypeptide of 293 amino acids and had seven active sites of XTH family, and then named as CmXTH （gene accession number HM752243）. In addition, The BLAST analysis showed that the deduced amino acid sequence of CmXTH showed high homology with other 19 chosen plant XTHs. Among of these, CmXTH shared closer genetic relationship with Gerbera jamesonii, Solanum lycopersicum, whereas had relatively distant relationship with Populus euparatica, Fragaria ananassa, Actinidia deliciosa, etc. [Conclusion] The cloned fragment was certainly the cDNA of XTH gene, which was associated with the petal growth and senescence in Chrysanthemum morifolium.

Identification of Senescence-associated Protein DpXTH1 and its Gene Cloning in Dahlia Petals

[Objective] This study aimed to explore the molecular mechanism of senescence in ethylene-insensitive flowers. [Method] The dahlia petals were used as matedal, and the senescence-associated proteins were isolated and identified using two-dimensional electrophoresis, mass spectrometry and an encoding gene was cloned using molecular biology techniques. [Result] In the two-dimensional elec- trophorogram of proteins from dahlia petals at building color, full flowering and flow- er senescence pedods, a total of 44 protein spots with differences in expression level more than two times were detected. From the 44 protein spots, xyloglucan （XTHs）, a senescence-associated protein, was iso- lated and identified and its expression level was increased continuously with the senescence process of dahlia petals. By using the total RNA of dahlia petals as matedal and a pair of degenerate pdmers, the cDNA sequence of XTH gene was cloned by RT-PCR. The encoding region of XTH gene has a full length of 882 bp, encoding 293 amino acid residues, and is named as DpXTH1 （Accession number： HM053613.1）. The cluster analysis showed that the amino acid sequence of DpXTH1 has high homology with those of XTHs in other plants. [Conclusion] The isolated and identified DpXTH1 from dahlia petals belonged to the XTH family in plants, and its biological function was associated with the senescence process and regulation of dahlia petals.

An Ethylene-inhibited NF-YC Transcription Factor RhNF-YC9 Regulates Petal Expansion in Rose

The speed of flower opening is closely related to their ornamental period.Ethylene functions as a negative regulator involved in the regulation of the petal expansion process.In this study,we isolated a NF-YC transcription factor gene,RhNF-YC9,fromrose petals.RhNF-YC9 expression was induced at the early stages of flower opening but was inhibited by ethylene treatment.Silencing RhNF-YC9 decreased the speed of petal expansion from stage 2 to stage 5.The expressions of 11 cell expansion-related genes involved in cell wall loosening,cell turgor modulation,and cytoskeleton remodeling were significantly down-regulated in RhNF-YC9-silenced petals.We also found that silencing RhNF-YC9 decreased the expression of gibberellin acid(GA)biosynthetic gene RhGA20ox while significantly increasing the transcripts of GA catabolic gene RhGA2ox,reducing the accumulation of GA4 and GA7.The influence of ethylene treatment on the expression of RhGA20ox and RhGA2ox showed the same trend.These results together suggested that RhNF-YC9 positively regulated the speed of petal expansion and mediated the crosstalk between ethylene and GA.Our findings revealed a new insight into the function of NF-YC transcription factors involved in ethylene-regulated petal expansion.

Optimal Control of a Universal Rotating Magnetic Vector for Petal-shaped Capsule Robot in Curve Environment

Steering control of a capsule robot in curve environment by magnetic navigation is not yet solved completely.A petal-shaped capsule robot with less steering resistance based on multiple wedge effects is presented,and an optimization method with two processes for determining the orientation of a pre-applied universal magnetic spin vector is proposed.To realize quick and non-contact steering swimming,a fuzzy comprehensive evaluation method for optimizing the steering driving angle is presented based on two evaluation indexes including the average steering speed and the average steering trajectory deviation,achieving the initial optimal orientation of a universal magnetic spin vector.To further reduce robotic magnetic vibration,a main target method for optimizing its final orientation,which is used for fine adjustment,is employed under the constrains of the magnetic moments.Swimming experimental results in curve pipe verified the effectiveness of the optimization method,which can be effectively used to realize non-contact steering swimming of the petal-shaped robot and reduce its vibration.

Light induces petal color change in Quisqualis indica(Combretaceae)

Petal color change, a common phenomenon in angiosperms, is induced by various environmental and endogenous factors. Interestingly, this phenomenon is important for attracting pollinators and further reproductive success. Quisqualis indica L.(Combretaceae) is a tropical Asian climber that undergoes sequential petal color change from white to pink to red. This color changing process is thought to be a good strategy to attract more pollinators. However, the underlying physiological and biochemical mechanisms driving this petal color change phenomenon is still underexplored. In this context, we investigated whether changes in pH, pollination, light, temperature or ethylene mediate petal color change. We found that the detected changes in petal pH were not significant enough to induce color alterations. Additionally, pollination and temperatures of 20-30℃did not alter the rate of petal color change; however, flowers did not open when exposed to constant temperatures at 15℃ or 35℃.Moreover, the application of ethylene inhibitor, i.e., silver thiosulphate, did not prevent color change. It is worth mentioning here that in our study we found light as a strong factor influencing the whole process of petal color change, as petals remained white under dark conditions. Altogether, the present study suggests that petal color change in Q. indica is induced by light and not by changes in petal pH, pollination, ethylene, or temperature, while extremely low or high temperatures affect flower anthesis. In summary, our findings represent the probable mechanism underlying the phenomenon of petal color change, which is important for understanding flower color evolution.

Rose Essential Oil Extraction from Fresh Petals Using Synergetic Microwave ＆ Ultrasound Energy： Chemical Composition and Antioxidant Activity Assessment

The aim of the present work was to investigate the synergetic effect of microwave and ultrasound treatment on the production, chemical composition and antioxidant activity of rose essential oil. The rose essential oil was extracted from fresh Rosa x damciscena Mill. petals by four methods, hydrodistillation, steam distillation, organic solvent extraction and ultrasounds followed by microwave hydrodistillation. The chemical composition of the extracts was analysed by GC-MS, and the antioxidant capacity by DPPH. It was found that both chemical composition and the antioxidant activity of the extracts depend on the extraction method. Overall it was found that microwaves coupled with ultrasonic treatment can be used effectively for the intensification of the extraction of monoterpenes and sesquiterpenes--fragrance bearing molecules--and equally, for increased antioxidant activity while using about 4 time shorter extraction time. The scale-up of the method was also evaluated. The results obtained in this research support the possible use of the US/MW method for the extraction of rose essential oil for the pharmaceutical and fragrance industry.

完备随机赋范模中的Drop定理与Petal定理

在随机赋范模中给出了L^0-drop的定义并在局部L^0-凸拓扑下证明了完备随机赋范模中的Drop定理与Petal定理,然后证明了它们与此拓扑下完备随机赋范模中的Ekeland变分原理是相互等价的;进而,利用(ε,λ)-拓扑与局部L^0-凸拓扑下基本结果之间的联系,得到了(ε,λ)-拓扑下完备随机赋范模中的Drop定理与Petal定理以及它们与该拓扑下完备随机赋范模中的Ekeland变分原理之间的等价性.

The phased chromosome-scale genome of yellowhorn sheds light on the mechanism of petal color change

Yellowhorn(Xanthoceras sorbifolium), especially its varieties, is the red petal yellowhorn(X. sorbifolium var. purpurea), an important tree species with great ornamental value, and its flower petals change color throughout the flowering period. In this study, we mainly focused on the mechanism of the petal color change with transcriptomics and metabolomics data. A phased chromosome-scale assembly of the red petal yellowhorn genome was generated using the PacBio high-fidelity reads, Illumina short reads, and Phase genomics Proximo Hi-C data. The final de novo assembly yielded 533.67 Mb with a contig N50 of 5.42 Mb, and 27 501 protein-coding genes were predicted. Notably, an alternate haplotig assembly was also obtained. Furthermore, a variation database for the alleles within the genome was constructed. Subsequently, the expression pattern of flower pigmentation-related genes and allelic expression imbalance events were investigated. Apart from 6 genes involved in the anthocyanin biosynthesis pathway regulated by the activation of 15 MYB-bHLH-WD40s, the increased expression of senescencerelated gene 1(SRG1) and 2-oxoglutarate-dependent dioxygenase(DIOX5) might also result in decreasing content of lutein and increasing abundance of(E/Z)-phytoene, cyanidin-3-O-rutinoside, and cyanidin-3-O-sambubioside. These changes in genes and metabolites were most likely related to the petal color change in red petal yellowhorn. This phased chromosome-scale genome assembly provides more accurate genomic information for future molecular breeding and facilitates allele function studies of the red petal yellowhorn.

The R2R3-MYB transcription factor GaPC controls petal coloration in cotton

Although a few cases of genetic epistasis in plants have been reported, the combined analysis of genetically phenotypic segregation and the related molecular mechanism remains rarely studied. Here, we have identified a gene(named GaPC) controlling petal coloration in Gossypium arboreum and following a heritable recessive epistatic genetic model. Petal coloration is controlled by a single dominant gene,GaPC. A loss-of-function mutation of GaPC leads to a recessive gene Gapc that masks the phenotype of other color genes and shows recessive epistatic interactions. Map-based cloning showed that GaPC encodes an R2R3-MYB transcription factor. A 4814-bp long terminal repeat retrotransposon insertion at the second exon led to GaPC loss of function and disabled petal coloration. GaPC controlled petal coloration by regulating the anthocyanin and flavone biosynthesis pathways. Expression of core genes in the phenylpropanoid and anthocyanin pathways was higher in colored than in white petals. Petal color was conferred by flavonoids and anthocyanins, with red and yellow petals rich in anthocyanin and flavonol glycosides, respectively. This study provides new insight on molecular mechanism of recessive epistasis,also has potential breeding value by engineering GaPC to develop colored petals or fibers for multifunctional utilization of cotton.

Anisotropic cell growth-regulated surface micropatterns in flower petals

Flower petals have not only diverse macroscopic morphologies but are rich in microscopic surface patterns, which are crucial to their biological functions. Both experimental measurements and theoretical analysis are conducted to reveal the physical mechanisms underlying the formation of minute wrinkles on flower petals. Three representative flowers, daisy, kalanchoe blossfeldiana, and Eustoma grandiflorurn, are investigated as examples. A surface wrinkling model, incorporating the measured mechanical properties and growth ratio, is used to elucidate the difference in their surface morphologies. The mismatch between the anisotropic epidermal cell growth and the isotropic secretion of surficial wax is found to dictate the surface patterns.

Study of variegated and white flower petals of Capparis spinosa expanded at dusk in arid landscapes

In this study, we provide the first evidence of two pairs of petals of the rapidly expanded and short-lived nocturnal flowers of Capparis spinosa L. （caper） during the prolonged drought period in Eastern Mediterranean region. The corolla of the winter-deciduous, perennial C. spinosa consists of two pairs of petals： a pair of white dis- tinct petals and a pair of connate variegated petals with green basal parts. The results indicated the presence of substantially different amounts of chlorophyll in the two pairs of petals, while their carbohydrates＇ content is com- parable with that of the green sepals. High resolution imaging of petal surfaces of short-lived flowers of C. spinosa, obtained by using scanning electron microscopy, revealed stomata on the adaxial epidermis on both the white and the green parts of the variegated petals; while dense hairs were found on the surface ofthe abaxial green parts of the variegated petals. Adaxial, epidermal cells of the variegated petals, viewed using atomic force microscopy, pos- sess a submicron, cuticular microfolding that differs between the white and the green parts of the petals. It appears that microridges on the adaxial, white parts of petals of C. spinosa compensate for an increase in cell surface area of the short lived petals, while the roughness of the green parts of petals was found to be higher than that of the white parts. Thus, the micromorphology of surfaces of epidermal cells is expected to affect optical properties and wettability of the floral tissues. These findings may be particularly important for understanding the performance of the short-lived petals of C. spinosa, which are exposed to dryland environments.

Proteomic Studies of Petal-specific Proteins in Soybean [Glycine Max(L.)Merr.] Florets

A survey of petal-specific proteomes of soybean(Glycine max(L.) Merr[Non-italic].) was conducted comparing protein expression profiles in different petals. Two-dimensional polyacrylamide gel electrophoresis reference maps of protein extracts from standard petals(SP), lateral wings(LW), keel petals(KP), and reproductive organs(RO)(a mixture of stamen and carpel) were obtained. Protein expression in the three petal types was compared using Image Master TM 2 D platinum 6.0 software. This indicated that the proportion of homologous proteins between SP and LW was 59.27%, between SP and KP was 61.48%, and between LW and KP was 60.05%. Within a mass range of 6.5-200.0 ku and pH 4.0-7.0, approximately 590, 646, 544, and 700 protein spots were detected in SP, LW, KP, and RO, respectively. A total of 82 differentially expressed proteins were detected. Sixty-four of these detected spots were differentially expressed and showed more than 2-fold changes in abundance; of these 64 proteins, 26 showed increased expression and 38 showed decreased expression. Among these spots, single organ-specific proteins were also identified.They were ID 49(60.9 ku), ID 45(50.0 ku), and ID 46(40.5 ku) in RO, ID 98(42.0 ku) in SP, and ID 05(29.0 ku) in KP. A total of 14 protein spots from 82 differentially expressed proteins were identified with LC-MS/MS. Further protein identification was conducted using the SwissProt and NCBInr databases. The identified proteins and their putative functions were discussed further. This was the first study reporting the comparison of petal protein profiles of soybean florets using proteomics tools.

Study on Mutant Induction of Gladiolus by in vitro Culture of Petals

Petals of Gladiolus ＇Rose Supreme＇ were used to establish regeneration system. Developmental characteristics of petals were observed. A total of 94 plantlets of petal somaclonal line were marked in Mj generation by ISSR molecular markers and traits were observed in M3 generation. The results showed that the best medium to induce callus was MS＋2, 4-D 4.0 rag＂ L-~＋6-BA 0.5 rag. L~ and the best medium to induce somatic embryogenesis was MS＋2, 4-D1.0 mg＇L-I＋TDZ0.3 mg-L-1. New petals could be formed from petal callus directly. Pigments of mother plant appeared on plantlets while they were formed from petals. Two mutants were obtained from petal somaclonal line in M3 generation which demonstrated the correctness of ISSR analysis in M1 generation.

Composition and antioxidant activity of Paeonia lactiflora petal flavonoid extract and underlying mechanisms of the protective effect on H_(2)O_(2)-induced oxidative damage in BRL3A cells

Flavonoids have attracted considerable attention due to their health benefits. This study aimed to investigate the flavonoid profiles and antioxidant activity of Paeonia lactiflora petal flavonoid extract(PPF). The UHPLC-ESI-Q-Exactive HF MS/MS method was established for characterization, and 21 predominant flavonoid compounds were tentatively identified in PPF. Among them, isoscutellarein-7-(6’-acetylallosyl-(1->2)-glucoside) and scutellarin methylester were discovered in PPF for the first time. Pretreatment with PPF significantly reduced H2O2-induced cell damage, ROS accumulation, and malondialdehyde content and increased the activity of SOD, CAT, and GSH-Px in buffalo rat liver 3A(BRL3A) cells. Moreover, the expression of nuclear Factor E2-related factor(Nrf2) was upregulated by PPF, whose expression trend was consistent with that of heme oxygenase-1(HO-1), glutamate-cysteine ligase catalytic subunit(GCLC), and NAD(P)H quinone oxidoreductase-1(NQO1). These findings suggested that herbaceous peony flavonoids can be used as a natural bioactive agent to prevent oxidative stress.

Biodiversity of the Micro-morphologies of the Petal Epidermis of Angiosperms &Their Scientific Aesthetics, Quasi-Geometry

The micro-morphologies and biodiversities of the epidermis of flower petals of angiosperms were reported for the first time. By manual slicing anatomy and microscopic photography technique, the micro-morphologies of the upper and lower epidermis of petals of some common ornamental flowers in Kunming were studied, and the biodiversities were discovered. The results showed these much-varied pigment cells appeared not only a new compensation to anatomy, but a new criteria to taxonomy, so that a brand new research field of “Cell Taxonomy” was established instead of the current “Chromosome Taxonomy” widely used in phytosystematics research. Furthermore, the most interesting and significant phenomena was their scientific aesthetics: these pigment cells of flower petals were quite special, planary, far different from the ordinary plant cells in plant organs & tissues. By comparison to ordinary geometry, these colorful cells of the fresh flower petals could be described as “Quasi-geometry” for their special origin and micro-morphological characteristics. As for the aspect of art, it was quite similar to “Quasi-crystal” discovered by Daniel Schechtman, so that the art future was discussed, obviously another new epoch of scientific-art history began.

New Reported Flavonol Characterized by NMR from the Petals of Talipariti elatum S. w. in Cuba

From yellow petals of Blue Mahoe, besides the known flavonoids gossypetin and gossypitrin, a new one gossypetin derivative was isolated from ethanolic extracts after Soxhlet extraction. Hence, in this study, we present a validated, sensitive and reliable NMR method for the simultaneous identification of flavonoids in this flower drug. Structure analyses of this flavonoid, revealed the identical glycoside moiety attached to a flavonol skeleton like gossypitrin, for which the structure of gossypetin-3'-O-β-glucoside was deduced from extensive NMR experiments.

M^2 factor of four-petal Gaussian beam

Based on the second-order moments, this paper derives an analytical expression of the M^2 factor of four-petal Gaussian beam. The results show that the M^2 factor is only determined by the beam order n. The corresponding numerical calculations are also given. As the beam order increases, the augment of M^2 factor is disciplinary. As the expression of M^2 factor is expressed in series form and becomes more complicated, a new concise formula of M^2 factor is also presented by using curve fitting of numerical calculations. When 3 ≤ n ≤ 200, the maximum error rate of fitting formula will not exceed 2.6% and the average error rate is 0.28%. This research is helpful to the applications of four-petal Gaussian beam.

Study on Petal-Sepal Mutant of Sunflower (Helianthus annuus) after Space Mutation

In this paper, we studied the morphological, histological and photosynthetic characteristics of the stably inherited sunflower petal-sepal mutant, and it was obtained by the space radiation-induced mutagenesis. Afterwards, we got following results: 1) The morphological characteristics represented that the inflorescence of petal-sepal mutant maintained the appearance and structure of capitulum, whereas no explicit tubular flower or ligulate flower was differentiated. 2) The histological characteristics revealed that the petal-sepal mutant only completed the inflorescence development and the differentiation of sepal primordia and inflorescence primordia, without entering the differentiation stage of tubular flower primordia, ligulate flower primordia, stamen primordia or pistil primordia. 3) The photosynthetic characteristics showed that the photosynthetic rate, transpiration and stomatal conductance of petal-sepal mutant were relatively weaker than the control plants. In the end, we concluded that the petal-sepal mutant of sunflower had only inflorescence differentiation, while several mutant genes were caused by radiation-induced mutation, which entered an infinitely recurrent development process rather than the floral differentiation stage. We also observed a few chloroplast structures in the paraffin section, combined with the results of photosynthetic characteristics of petal-sepal mutant, and then we believed that the inflorescence of petal-sepal mutant was involved in photosynthesis to accumulate energy for plant growth.

Extraction of Dyes from Sunflower Petal and Their Fourier Transform Infrared Characterization

Three solvents of different polarities(water,methanol and 1%NaOH solution)were used to extract dyes that produced different shades from dried sunflower(Helianthus annuus)petal.The extraction procedures using different solvent types were carried out separately.The dye extracts were thereafter subjected to Fourier Transform Infrared Spectrometry(FT-IR)analysis for characterization in terms of functional groups.The intensities of the extracted dyes on the shade of colours obtained on pieces of cotton material varied from yellow in methanolic extract to light yellow in aqueous and black in 1%NaOH solution extracts.The results obtained from the FT-IR analysis revealed the presence of several useful functional groups such as N-H,C=H,O-H and C=O in the extracts.

自主性教师培养模式的研发与实验:PETALS第二语言教师培训模式示例

随着世界掀起汉语学习热潮,汉语作为第二语言的教师培训需要激增;但是,汉语教师的培训效度却也备受关注。于此,本文提出了基于建构主义下的PETALS第二语言教师培训模式,该模式以21世纪最新教师培养理论为依据,采用程序教学法,融合鹰架法、显性教学法,结合第二语言教学模式,以注重培养教师的第二语言课堂教学意识以及实际课堂教学能力。在一个为期60小时的短期课程中,教师通过以反思为主的评量性学习法(Assessment for Learning)(课前、课中、课后反思与评量)和责任逐渐转移模式(The Gradual Release of Responsibility Model)来同步培养学员的认知与元认知能力:一、第二语技能教学的概念与相关方法,包括听、说、读、写四种语言能力的培养;二、第二语言技能教学的意识、策略与监控能力(Self Regulating)。质性研究数据显示该培训模式能有效地唤醒教师的第二语言课堂教学意识、有效培养教师的自主性教学设计能力。