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- Author or Editor: Chen Jiang x
Volatile chemicals emitted from the flowers of chinese wisteria (Wisteria sinenesis) and japanese wisteria (W. floribunda) were collected using a dynamic headspace technique and identified using gas chromatography–mass spectrometry; 28 and 22 compounds were detected from chinese wisteria and japanese wisteria flowers, respectively. These chemicals can be classified into four major classes, including fatty acid derivatives, benzenoids/phenylpropanoids, terpenoids, and nitrogen-containing compounds. Two monoterpenes, (E)-β-ocimene and linalool, belonging to the class of terpenoids, were the most abundant compounds emitted from both species. Despite strong similarity, the floral volatile profiles of the two species displayed variations in both quality and quantity. Chinese wisteria was selected as a model for further study of volatile emission from different parts of flowers, emission dynamics, and regulation of floral scent production. Although floral volatiles were detected from all flower parts, petals emitted the most. The emission of floral volatiles displayed a diurnal pattern with the maximal emissions occurring during the daytime. This rhythmic pattern was determined to be light-dependent. Regulation of floral volatile emission by exogenous chemicals, including silver thiosulphate (an ethylene inhibitor), salicylic acid, and jasmonic acid, also was analyzed. Generally, jasmonic acid promoted the emission of floral volatiles. In contrast, neither silver thiosulphate nor salicylic acid showed a significant effect on floral volatile emission. The results presented in this article suggest that wisteria can serve as a useful system for exploring novel biochemistry of floral scent biosynthesis. They also build a foundation for the study of the biological/ecological significance of floral volatiles on the reproductive biology of wisteria species.
Volatile chemicals emitted from the flowers of globe amaranth (Gomphrena globosa) were collected using a dynamic headspace technique and analyzed using gas chromatography–mass spectrometry. Among the four globe amaranth cultivars analyzed, Fireworks was the highest producer of floral volatiles. The flowers of the other three cultivars, Las Vegas White, Las Vegas Pink, and Las Vegas Purple, emit less volatiles, both qualitatively and quantitatively, than ‘Fireworks’. ‘Fireworks’ was chosen for detailed characterization of regulation of floral volatile emission. A diurnal pattern of emission of floral volatiles was observed from the flowers of ‘Fireworks’. In addition, the emission pattern was not significantly affected by light, suggesting that the circadian clock plays a major role in the regulation of volatile emission. The emission of floral volatiles from ‘Fireworks’ flowers that were treated with several chemicals was also analyzed. The treatment with silver thiosulphate, an ethylene inhibitor, led to enhanced emission of total volatiles. In contrast, the treatments with salicylic acid and jasmonic acid led to enhanced emission of total floral volatiles at 4 h but reduced emission at 24 h after the treatment. Biochemical pathways leading to the production of the major floral volatiles of globe amaranth are proposed and partly validated by cluster analysis of floral volatiles emitted from ‘Fireworks’ flowers under various conditions. The implications of the results of this study to the understanding of the reproductive biology of globe amaranth and the breeding of novel globe amaranth cultivars are discussed.
Mei (Prunus mume Sieb. et Zucc.) flower is one of the candidates for the national flower of the People's Republic of China. Several major anthocyanins from the flowers of P. mume Sieb. et Zucc. were isolated with MeOH-HOAc-water (10:1:9, v/v), and purified by paper chromatography and subsequent column chromatography. Specific chemical reactions, chromatographic and spectroscopic analyses indicated that the anthocyanins in `Nanjing Hongxu' (Nanjing red-bearded) were cyanidin 3-O-(6'-O-α-rhamnopyranosyl-β-glucopyranoside) and cyanidin 3-O-(6'-O-galloyl-3'-O-β-glucopyranosyl-β-glucopyranoside). Anthocyanins in `Nanjing Hong' (Nanjing red) were cyanidin 3-O-(6'-O-α-rhamnopyranosyl-β-glucopyranoside), cyanidin 3-O-(6'-O-galloyl-β-glucopyranoside) and cyanidin 3-O-(6'-O-E-feruloyl-βglucopyranoside). In addition to contributing to the blue flower color, the anthocyanins may improve the ability of the two cultivars to survive at low temperatures.
By using the micro-volume radio-ligand binding essay, the changes in the kinetic characteristics of the abscisic acid (ABA)-binding protein(s) of the Kyhoh grapevine (Vitis vinifera × V. labrusca) fruit during the different stages of fruit development have been studied. The changes in the berry volume growth, concentration of sugar, organic acids, and ABA in fruit mesocarp have been surveyed, especially for studies of ABA-binding protein. The dissociation constant (Kd) and ABA binding maximum (Bmax) were determined by the Scatchard plots for ABA binding in microsomes of the fruit. They are Kd = 17.5, 50.0, 6.3, 13.3 nmol·L–1; Bmax = 98.6, 523.0, 41.6, 85.4 μmol·mg–1 protein, respectively, for the fruit developmental phase I, II, veraison, and phase III. The Scatchard plots showed a rectilinear function for all of the developmental phases including veraison, which suggests the sole ABA-binding site of high affinity for ABA in the fruit microsomes, but this site could either be only one kind of the same protein or consist of more kinds of different proteins for different developmental stages. The binding affinity of ABA-binding protein(s) for ABA was shown to be higher at veraison time than during other developmental phases; this binding affinity increased nearly by 10 times from phase II to veraison, while the concentration (Bmax) of the ABA-binding protein(s) decreased to the minimum at veraison. The very low concentration of ABA at veraison may be able to trigger the onset of fruit ripening due to the increase of the binding affinity of ABA-binding protein(s) for ABA at this time. The possible functions of the ABA-binding protein(s) for fruit development during the different developmental stages were discussed, and it is suggested that the protein(s) detected could be the putative ABA receptor(s) or transporter(s) for the action of this plant hormone in grapevine.
The abscisic acid (ABA) has a key role in the regulation of grapevine fruit ripening, but the cellular and molecular biological mechanism of the hormone action in the fruit ripening remains unknown. By means of differential centrifugation, microsomes were prepared from Kyoho grapevine (Vitis vinifera L. × V. Labrusca L.) berries, and using the microsomes, we have obtained evidence for the occurrence of specific ABA-binding sites on the membranes with the microvolume radio-ligand binding assay. The binding sites had saturability, high affinity, and low capacity. The results of trypsin and dithiothreitol treatments to the microsomes suggested that ABA binding sites had the properties of proteins that might have disulfide group located at or near the binding site. The binding maximum amount of ABA in the microsomes was at pH 6.0 and the activity of ABA binding proteins was higher at 25 than at 0°C (temperature). The amount of ABA bound reached 54% of the ABA binding maximum (Bmax) for 10 minutes of incubation and Bmax reached for 30 minutes. The dissociation constant (Ka) and Bmax of ABA binding proteins in the microsomes were 17.5 nmol/L and 98.4 fmol/mg protein, respectively.
The consumption of fresh muskmelons (Cucumis melo reticulatus L.) has been linked to severe illness outbreaks due to contamination with bacterial pathogens. Antimicrobial essential oils (EOs) were incorporated into wash water sprays and evaluated as potential agents for postharvest disinfection of ‘Athena’ muskmelons. Freshly harvested fruits were sprayed with 0.5% EOs from cinnamon leaf, thyme, or clove bud emulsified in a whey protein emulsion (WP) as potential washing disinfectants, together with deionized water, water with 200 µL·L−1 free chlorine (pH 7, free turbidity), or oil-free WP as controls. Melons were treated, stored at 4 °C and then evaluated weekly for weight loss, rind color, mesocarp firmness and the compositional quality traits soluble solids content (SSC), pH, β-carotene content, and total ascorbic acid (AsA) for up to 21 days. Essential oil–treated melons were not different from controls in fruit quality and composition with the exception of fruits treated with thyme oil, which were statistically lower in SSC (0.8 °Brix) than those treated with water or cinnamon oil treatment. Internal carbon dioxide was statistically higher (≈0.1% higher in value, equal to a 25% increase) in muskmelons receiving whey protein–based treatments after storage for at least 7 days. Overall, our results suggest that EOs as disinfectants have little effect on quality or composition of muskmelon fruit.
The sand pear (Pyrus pyrifolia Nakai) is an important fruit crop in China. In this study, simple sequence repeats (SSRs) were used to estimate the level and pattern of genetic diversity among 233 sand pear landraces collected from 10 different geographic regions in China. The results demonstrated that the SSR technique is an effective tool for assessing genetic diversity and the geographic pattern of genetic variation among sand pear landraces of different origins. A total of 184 putative alleles was detected using 14 primer pairs with an average of 13.1 alleles per locus. The mean expected heterozygosity and observed heterozygosity across all loci were 0.705 and 0.671, respectively. High genetic diversity was found in all populations except for that originated from Jiangxi (A e = 3.149; H e = 0.655), whereas at the regional level, those from central China were less diverse than those from other regions. Analysis of molecular variance showed that most genetic differences resided among landraces within populations. Additionally, unweighted pair group with arithmetic average clustering and principal component analysis plotting based on Nei's genetic distance revealed distinct gene pools in agreement with geographic distribution.
We investigated the FT/TFL1 family of peach (Prunus persica), a gene family that regulates floral induction in annual and perennial plants. The peach terminal flower 1 gene (PpTFL1) was expressed in a developmental and tissue-specific pattern that, overall, was similar to that of TFL1 orthologs in other woody Rosaceae species. Consistent with a role as a floral inhibitor, ectopic expression of PpTFL1 in arabidopsis (Arabidopsis thaliana) delayed flowering and prolonged vegetative growth. Other members of the peach FT/TFL1 family were identified from the sequenced genome, including orthologs of flowering locus T, centroradialis, brother of ft, and mother of ft and tfl. Sequence analysis found that peach FT/TFL1 family members were more similar to orthologous genes across the Rosaceae than to each other. Together these results suggest that information on genes that regulate flowering in peach could be applied to other Rosaceae species, particularly ornamentals.
The response to reduced light intensity of two contrasting cultivars Puma Sunny (shade intolerant) and Gongzi (shade tolerant) was characterized in terms of plant height, the root/shoot ratio, photosynthetic capacity, and the morphology and ultrastructure of their chloroplasts and phloem companion cells. The initial response to shading of cultivar Puma Sunny plants was to extend their stems, and while the equivalent response of cultivar Gongzi was less marked. Shading depressed the maximum relative electron transport rate (rETR) in both cultivars, and while the efficiency of light capture in cultivar Puma Sunny was compromised by shading, this was not the case for cultivar Gongzi. Low levels of incident light inhibited the formation of starch grains in the chloroplast and increased the volume of interspace between the grana lamellae. In cultivar Puma Sunny, but less so in cultivar Gongzi, the chloroplasts became more slender and the stroma lamellae more swollen. Adjusting chloroplast morphology by developing extra layers of grana lamellae and maintaining the integrity of the phloem companion cells are both adaptations which help make ‘Gongzi’ a more shade-tolerant cultivar.