谷胱甘肽对采后石刁柏木质化和食用品质的影响

在(24±1)℃条件下,谷胱甘肽(GSH)可显著抑制采后石刁柏木质素合成前体总酚的含量及与木质素合成相关的苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)活性上升,延缓叶绿素、可溶性糖、可溶性蛋白和核酸的降解,降低活性氧和木质素含量,从而保持石刁柏的鲜嫩品质.     

Comparison of gas chromatography-mass spectrometry,radioimmunoassay and bioassay for the quantification of gibberellin A9 in norway spruce (Picea abies (L.) Karst.)

Quantitative estimates of gibberellin A₉ in Norway spruce extracts obtained by gas chromatography-mass spectrometry, radioimmunoassay (RIA_ and bioassay were compared after successive purifications of the extracts. The extracts were assayed in several dilutions with and without the addition of standard gibberellin A₉, thus showing the effect of extract components on the response of the assays. Radioimmunoassay produced estimates comparable to gas chromatography-mass spectrometry after one purification step by high-performance liquid chromatography. Extracts purified by polyvinylpyrrolidone-column chromatography and solvent partitioning but not high-performance liquid chromatography resulted in inaccurate RIA estimates. The performance of the RIA could be monitored by logit-log transformations of the standard curve and extract dilution curve and by calculating the slope of the standard addition curve. It was, however, not possible to correct for the interference caused by extract components by the standard addition procedure. Quantifications by Tan-ginbozu dwarf-rice bioassay were accurate, but a large and unpredictable variation makes it unsuitable for quantitative determinations.Abbreviations FW fresh weight - GA₉ gibberellin A₉ - GA₉–Me methylated GA₉ - GC-MS gas chromatography-mass spectrometry - HPLC high performance liquid chromatography - MID multiple-ion detection - RIA radioimmunoassay     

Development of a bioassay to assess resistance to Fusarium oxysporum (Schlecht.) in asparagus (Asparagus officinalis L.)

Fusarium oxysporum is one of the major pathogens causing root and crown rot in asparagus. Breeding of cultivars resistant to F. oxysporum would be the most efficient strategy for pathogen control. In this study, a bioassay was developed for screening seedling resistance. The non‐destructive bioassay comprises inoculation with a highly aggressive F. oxysporum isolate, incubation in a climate chamber and quantification of disease symptoms by a digital image analysing system and a PTA‐ELISA. This bioassay is simple to implement and demonstrated high reproducibility. Subsequently, it was used to determine the resistance behaviour of 16 asparagus genotypes to F. oxysporum. The asparagus cultivars revealed different levels of susceptibility, whereas the wild relative A. densiflorus was confirmed to be resistant.     

Effect of light and gibberellic acid on cell division in the first foliage leaf of durum wheat (Triticum durum Desf.)

The present paper is part of a research program which aims at a quantitative analysis of the effects of light and gibberellic acid (GA₃) on growth of the first foliage leaf in durum wheat (Triticum durum Desf.). Since leaf growth is the combined result of the increase in cell number (cell division) and cell enlargement, the influence of light and GA₃ treatment on cell division in the basal meristem of the first leaf in two cultivars, Cappelli and Creso, was investigated. Creso is a short-strawed cultivar carrying the Gai 1 gene which influences both plant height and insensitivity to applied GA₃. Cell division, as measured by mitotic index, was similar in darkness, continuous red light and dichromatic irradiation (far-red plus red), while lower mitotic rates were observed under continuous far-red light: this indicates that the response of cell division is modulated by a high-irradiance reaction of phytochrome in both cultivars. The two cultivars showed different responses to blue light. In Cappelli, blue light and dichromatic irradiation (blue plus red) gave lower mitotic indices than the dark control, indicating the action of a specific blue-light-absorbing photoreceptor, whereas in Creso the response kinetics to all light regimes which included blue light were more complex. On the basis also of the results obtained with GA₃ application in Cappelli, it appears that (i) the hormonal treatment is able to change the pattern of mitotic index only in the presence of the action of a blue-light receptor and (ii) the different responses of the two cultivars could be the result of different endogenous hormonal levels. The importance of the observations in relation to the data for first-leaf longitudinal growth reported in a previous paper (Baroncelli et al. 1984, Planta 160, 298–304) is discussed.Abbreviations BL blue light - D darkness - FR far-red light - GA gibberellin - GA₃ gibberellic acid - m.i. mitotic index - Norflurazon 4-chloro-5-(methylamino)-2-(,,,-trifluoro-m-totyl-3(2H)) pyridazinone - R red light - WL white light - phytochrome photoequilibrium     

Regeneration of haploid plants from isolated microspores of asparagus (Asparagus officinalis L.)

High percentages of micro-calli and micro-derived embryos were produced from isolated asparagus microspores at late uninucleate stage on MS liquid medium supplemented with 1.0 mg l^–1 2,4-D and 0.5 mg l^–1 BA. Two types of calli, namely compact callus (CC) and loose callus (LC), were found. Plantlets were regenerated via organogenesis, when these calli were transferred onto MS solid medium supplemented with 1.0 mg l^–1 BA and 0.2 mg l^–1 IBA 6 weeks. Embryos were produced from liquid cultured microspores, or from solid cultured micro-calli. The frequencies of haploid plant production from organogenesis and embryogenesis were compared. Effects of plant growth regulators on callus production, plantlet regeneration, and haploid plant production were tested. The combination of BA 1.0 mg l^–1 and IBA 0.2 mg l^–1 resulted the highest precentage of haploid plant production (7.7% from CC, 4.3% from LC).Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - IBA 3-indolybutyric acid - BA 6-binzyladinine - NAA naphtalene acetic acid - MS Murashige and Skoog     

The physical map of the chloroplast DNA from Asparagus officinalis L.

The genus Asparagus consists of 100–300 species of both dioecious and hermaphrodite plants. Since there are diploid, tetraploid, and hexaploid plants in this genus, RFLP (restriction fragment length polymorphism) analysis of chloroplast DNA (ctDNA) is suitable for examining the phylogenetic relationships. We have constructed a physical map of the ctDNA of garden asparagus (A. officinalis L. cv Mary Washington 500 W) using five restriction endonucleases, namely, BamHI, PstI, SalI, HindIII, and XhoI. Asparagus ctDNA was digested with restriction enzymes and cloned into plasmid and phage vectors, and a clone bank was constructed that covered 70% of the genome. A physical map was constructed by Southern hybridization of total DNA from asparagus with homologous and heterologous probes. The asparagus ctDNA was about 155 kb long and it contained two inverted repeats (23kb each) separated by a large single-copy region (90kb) and a small single-copy region (19kb). Fifteen genes, encoding photosynthesis-related proteins, rDNAs, and tRNAs, were localized on the physical map of asparagus ctDNA. Comparing the length and the gene order of asparagus ctDNA with that of other plants, we found that asparagus ctDNA was similar to tobacco ctDNA but different from rice ctDNA. The restriction patterns of the ctDNAs from several varieties of A. officinalis and three species of Asparagus were analyzed. The restriction patterns of the varieties of A. officinalis were very similar, but polymorphisms were detected among the three species of Asparagus.     

Microarray Analysis of Gene Expression Involved in Anther Development in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

In flowering plants, anthers bear male gametophytes whose development is regulated by the elaborate coordination of many genes. In addition, both gibberellic acid (GA₃) and jasmonic acid (JA) play important roles in anther development and pollen fertility. To facilitate the analysis of anther development genes and how GA₃ and JA regulate anther development, we performed microarray experiments using a 10-K cDNA microarray with probes derived from seedlings, meiotic anthers, mature anthers and GA₃- or JA-treated suspension cells of rice. The expression level change of 2155 genes was significantly (by 2-fold or greater) detected in anthers compared with seedlings. Forty-seven genes, representing genes with potential function in cell cycle and cell structure regulation, hormone response, photosynthesis, stress resistance and metabolism, were differentially expressed in meiotic and mature anthers. Moreover, 314 genes responded to either GA₃ or JA treatment, and 24 GA₃- and 82 JA-responsive genes showed significant changes in expression between meiosis and the mature anther stages. RT-PCR demonstrated that gene y656d05 was not only highly expressed in meiotic anthers but also induced by GA₃. Strong RNA signals of y656d05 were detected in pollen mother cells and tapetum in in situ hybridization. Further characterization of these candidate genes can contribute to the understanding of the molecular mechanism of anther development and the involvement of JA and GA₃ signals in the control of anther development in rice.     

Cryopreservation of dried axillary buds from plantlets of Asparagus officinalis L. grown in vitro

Dried axillary buds from plantlets of Asparagus lofficinalis L. grown in vitro were successfully cryopreserved. Single node segments (5mm in length) with axillary bud were taken from mature in vitro plantlets. The segments were precultured on solidfied Murashige-Skoog medium (1962) containing 0.7M sucrose at 25 °C in light for 2 days. Thereafter, these precultured segments were subjected to dehydration with silica gel at room temperature for 0 to 24 h. The axillary buds of precultured segments tolerated dehydration to about 14% water content(FW) with 50% lethality (LD₅₀) and the threshold water content at which the dried buds remained alive after exposure to liquid nitrogen was 16.9%(LD₅₀). The maximum rate of survival of cryopreserved buds was about 71% of untreated control. Surviving buds produced shoots and regenerated into plantlets. These results demonstrate the feasibility of cryopreserving dried axillary buds from in vitro plantlets.Abbreviations MS Murashige and Skoog medium(1962) - LN liquid nitrogen - FW fresh weight basis - LD₅₀ the water content at 50% lethality - ABA abscisic acid - NAA -naphthalene acetic acid - BA 6-benzyladenine - DTA differential thermal analysis     

3 beta,13-dihydroxylated C20 gibberellins from inflorescences of Rumex acetosa L

Using full scan GC-MS a wide range of gibberellins (GAs) was identified in the young inflorescences of the dioecious species Rumex acetosa L., consistent with the ubiquitous early 13-hydroxylation pathway in both male and female plants. In addition, R. acetosa is the first species in which all three 3beta,13-dihydroxylated C(20)-GAs-GA(18), GA(38) and GA(23)-have been identified in the same organism, suggesting an early 3beta,13-dihydroxylation biosynthesis pathway in this species. Authentic GA(18), GA(38) and GA(23) were synthesized and their effects and that of GA(1), a GA common to both pathways, on the time to inflorescence emergence was investigated. GA(1) accelerated the emergence of inflorescences in both male and female plants. In addition some evidence for biological activity per se of the C(20)-GA(38) was obtained.     

Isolation and Identification of Fructo-oligosaccharides in Roots of Asparagus (Asparagus officinalis L.)

Eight fructo-oligosaccharides were isolated from purified oligosaccharide fractions of the roots of Asparagus officinalis L. (Liliaceae). By examination of constituent sugars, gas-liquid-chromatographic analysis of methyl derivatives, and investigation of partial acid hydrolyzates and products of β-fructofuranosidase action, they were confirmed to be 1^F(1-β -fructofuranosyl)_n sucrose [n = 1 (1-kestose), 2 (nystose), and 3], 6^G (1-β-fructofuranosyl)_n sucrose [n = 1 (neokestose), 2, and 3], 1^F,6^G-di-β-fructofuranosyl sucrose, and a new pentasaccharide 1^F (1-β-fructofuranosyl)₂-6^G-β-fructofuranosyl sucrose.     

Occurrence of fumonisins in asparagus (asparagus officinalis L.) and garlic (allium sativum L.) from Germany

Fusarium proliferatum is able to produce fumonisins and is considered a pathogen of many economically important plants (e.g. corn, rice, asparagus) [1]. The occurrence of fumonisin FB₁ inF. proliferatum infected asparagus spears from Germany was investigated using a liquid chromatography/electrospray ionization-mass spectrometry (LC-ESI-MS) method with isotopically labeled fumonisin FB₁-d₆ as internal standard. Asparagus samples were harvested in July 2000 and screened forFusarium species. AltogetherF. oxysporum, F. proliferatum and F. sambucinum were isolated from the spears. The samples infected with F.proliferatum were subsequently analyzed for fumonisins. FB₁ was detected in 9 of the 10 samples in amounts ranging from 36.4 ng/g to 4513.7 ng/g (based on dry weight). Fumonisins FB₂ and FB₃ were found in six samples in lower concentrations. In asparagus spears of June 2002 we could findF. proliferatum in 6% of the samples, however no fumonisins were detectable. Furthermore the capability of producing FB₁ by the fungus in garlic bulbs was investigated. Therefore garlic was cultured inF. proliferatum contaminated soil and the bulbs were screened for infection with F.proliferatum and for the occurrence of fumonisins by LC-MS. F.proliferatum was detectable in the garlic tissue and all samples contained FB₁ (26.0 ng/g to 94.6 ng/g). This is the first report of the natural occurrence of FB₁ in German asparagus spears and furthermore our findings suggest a potential for natural contamination of garlic bulbs with fumonisins. For detailed results and methods see Ref. [2].     

Germination response of Arabian desert species to gibberellic acid and potassium nitrate seed treatment

Abstract

Desert plant species commonly use seed dormancy to prevent germination during unfavorable environmental conditions and thus increase the probability of seedling survival. Seed dormancy presents a challenge for restoration ecology, particularly in desert species for which our knowledge of dormancy regulation is limited. In the present study the effect of gibberellic acid (GA₃) and potassium nitrate (KNO₃) on seed dormancy release was investigated on eight Arabian desert species. Both treatments significantly enhanced the germination of most species tested. GA₃ was more effective than KNO₃ in enhancing germination percentage, reducing mean germination time and synchronizing the germination in most of the studied species. Light requirement during germination was species-specific, but in general the presence of light promoted germination more effectively when combined with KNO₃ and GA₃. The wide variation in dormancy and germination requirements among the tested species is indicative of distinct germination niches, which might assist their co-existence in similar habitat/environmental conditions. Seed pre-treatments that optimize germination in this habitat must therefore be assessed for individual species to improve the outcomes of ecological restoration.     

Major anthocyanins from purple asparagus (Asparagus officinalis)

Two major anthocyanins (A1 and A2) were isolated from peels of the spears of Asparagus officinalis cv. Purple Passion. They were purified by column, paper and high-performance liquid chromatographic separations, and their structures were elucidated by high-resolution Fourier transform ion cyclotron resonance mass spectrometry (HR-FT-ICR MS), 1H, 13C and two-dimensional NMR spectroscopic analyses and either acid or alkaline hydrolysis, respectively. A1 was identified as cyanidin 3-[3'-(O-beta-d-glucopyranosyl)-6'-(O-alpha-l-rhamnopyranosyl)-O-beta-d-glucopyranoside], whereas A2 was cyanidin 3-rutinoside, which is widely distributed in higher plants. Oxygen radical absorbance capacity (ORAC) assays proved their high antioxidant activities.     

Appearance and immunohistochemical localization of UDP-glucose: coniferyl alcohol glucosyltransferase in spruce (Picea abies (L.) Karst.) seedlings

UDP-glucose: coniferyl alcohol glucosyltransferase was detected in hypocotyls of spruce (Picea abies (L.) Karst.) seedlings. Enzyme activity rose after germination to maximal activity on about the 10th day and then rapidly declined. An antiserum against the glucosyltransferase isolated from cambial sap of spruce (Schmid and Grisebach, 1982, Eur. J. Biochem. 123, 363–370) was employed for localization of the enzyme in cross sections of hypocotyls from 10-d-old spruce seedlings, using the immunofluorescent technique. The results show that the transferase is located predominantly in the epidermal and subepidermal layers and in the vascular bundles. Intracellularly, the enzyme is located in the parietal cytoplasmic layer. The results corroborate the assumption that coniferin (coniferyl alcohol -D-glucoside) participates in lignification of spruce.     

Modelling the effects of temperature and wetness on the polycyclic phase of Stemphylium vesicarium,the pathogen causing purple spot on asparagus (Asparagus officinalis L.)

The polycyclic phase of Stemphylium vesicarium is the key factor for the forecast and integrated control of purple spot on asparagus. The annual dynamics of airborne conidia were determined under field conditions by conidia traps. From 2013 to 2015, conidia became airborne at the earliest at mid‐July, but the number trapped was considerably enhanced only after mid‐August, early September. The cumulative percentage of trapped conidia was best described using a logistic function depending on the daily temperature sum (base 0°C) accumulated only on days with >0.2 mm of rainfall (R² = .81). The germination of conidia was modelled by a generalized beta‐modified Chapman Richards function, and the germ tube length was modelled by a generalized beta‐power function. Conidia germinated in a wide temperature range, with an optimum at 23.3°C, whereas germ tube length had a narrow nearly optimum temperature range around 28.7°C, which indicates that infection by conidia is more restricted by germ tube growth than by germination. The effect of temperature on the number of lesions produced by two strains on green asparagus spears had the narrowest optimum range (optimum at 21.9°C) of all parts of the polycyclic phase. In plant tissue, the spread of the fungus depends on the mycelium growth. The mycelium growth of the four strains, which was modelled with data from a petri dish experiment, had an optimum temperature at 24.7°C.     

Hormone-response mutants of Arabidopsis thaliana (L.) Heynh. impaired in somatic embryogenesis

Plant hormones are considered to be the key factors involved in triggering in vitro induced plant morphogenesis, including somatic embryogenesis (SE). Mutants affected in SE and altered in hormonal response therefore provide valuable material for genetic research on in vitro induced plant embryogenesis. The capacity for SE was studied in 27 mutants with defects in response to different plant hormones: auxin, ABA, gibberellin and cytokinin, and evaluated in 2-week-old mutant and wild-type cultures in terms of their efficiency and productivity. SE was induced in vitro via a direct morphogenic pathway, through the culture of immature zygotic embryos on standard solid medium with 5 μM 2,4-D. The majority of the analyzed mutants displayed a significantly impaired capacity for SE; and those affected belonged to several different hormone-defective groups, including forms affected in auxin (axr4), gibberellin (ga) and ABA (abi, hyl1, cpb20, abh1) response. These mutants showed a significant decrease in embryogenic response as manifested by a low efficiency and/or productivity of SE. Additionally, SE efficiency was analyzed for axr4-1 mutant on media supplemented with different auxins while GA₃ and inhibitors of gibberellins (uniconazol P and paclobutrazol), were applied for pkl1-1-mutant. The selected mutants provide a valuable research tool for studying the molecular mechanisms determining the induction of embryogenesis in cultures of somatic tissues. Their usefulness in further studies is discussed.     

外源赤霉素对紫斑牡丹种子萌发的影响

以紫斑牡丹种子为试验材料,研究不同浓度的赤霉素(GA_3)处理对种子生根以及生根过程中营养物质、酶活性和内源激素水平变化的影响,为探讨紫斑牡丹种子萌发机制提供依据。结果表明:(1)GA_3处理能够促进种子生根,并以300 mg/L GA_3处理对种子生根效果最好,与对照相比可提前14.67 d生根,生根率可达71.00%。(2)与对照相比,GA_3处理可以在0～15 d时促进种子淀粉水解和可溶性糖的积累,并加速可溶性蛋白的消耗,在0～30 d促进过氧化物酶(POD)活性的提高,从而促进种子萌发生根。(3)在种子沙藏生根过程中,种子脱落酸(ABA)含量呈下降趋势,赤霉素(GA)、玉米素核苷(ZR)和吲哚乙酸(IAA)含量均表现出先上升后下降的趋势,与对照相比,GA_3处理可使种子GA、ZR和IAA的含量在沙藏前期明显上升,以解除种子休眠。研究发现,外源GA_3处理可以调控紫斑牡丹种子内源激素含量和POD活性的变化,促进营养物质转化,从而提前解除种子休眠使其萌发。     

CCC and Prohexadione-Ca Enhance Rhizome Growth and Lateral Bud Production in Rhubarb (<Emphasis Type="Italic">Rheum rhabarbarum</Emphasis> L.)

Accelerating rhizome growth is crucial to enhancing propagule production in rhubarb (Rheum rhabarbarum L.) because the crop is propagated through rhizome divisions. This can be achieved through manipulating source-sink activity. This study tested the hypothesis that synthetic plant growth retardants Prohexadione-Ca and CCC enhance rhizome growth in rhubarb. Two different concentrations of these plant growth retardants and GA₃ (positive control) were foliarly applied on the cultivar German Wine at three stages of shoot growth under greenhouse conditions. Both Prohexadione-Ca and CCC favorably enhanced rhizome growth through suppressing shoot growth. CCC at 3000 mg L⁻¹ produced the best results and the effect was apparent when applied at 12 weeks after shoot emergence. The rhizome diameter, fresh weight, and the number of viable buds were enhanced significantly in plants sprayed with CCC 3000 mg L⁻¹. Both Prohexadione-Ca and CCC were equally effective in enhancing dry mass and starch allocation preferentially toward the rhizome. Prohexadione-Ca- and CCC-induced rhizome growth enhancement could possibly be due to their known role as GA biosynthesis inhibitors or through increasing photosynthetic efficiency and preferentially reallocating carbohydrates to the rhizome.     

Effect of kinetin and GA3 on in vitro ovule embryo culture of Cucumis melo L.

The ability of Cucumis melo embryos of different ages to form plants in vitro was studied in order to rescue hybrid embryos between C. melo and Cucumis metuliferus. Plants were grown in a glasshouse at temperatures ranging from 15°CN-28°CD. Best results were obtained with ovule embryos excised 17 days after pollination. At this age, kinetin of 0.5 mg l^–1 was found optimal for culturing embryo development. Similar results were obtained with ovule embryos excised 14 days after pollination which cultured on 0.5 mg l^–1 kinetin with 0.5 mg l^–1 GA₃.     

盐胁迫下赤霉素对黄瓜种子萌发及幼苗生长的影响

研究外源GA₃对盐胁迫下黄瓜种子萌发和幼苗生长的影响。结果表明,添加不同质量浓度GA₃的各处理,其发芽率、发芽势和发芽指数均显著高于NaCl胁迫处理,其中以100 mg/L GA₃处理的发芽势、发芽率和发芽指数最高,幼苗的叶面积、根长、根冠比也最大,同时叶片中叶绿素含量最高,幼苗叶片的光合速率(P_n)、气孔导度(G_s)、胞间CO₂摩尔分数(C_i)及蒸腾速率(T_r)等均达到最大;而当赤霉素的质量浓度为50 mg/L时,叶片中的POD活性为2 005 U/(g·min）,达最大值。