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Herbaceous peony (Paeonia lactiflora Pall.) is an ornamental plant with huge potential in the international flower market. Similar to the flowers of most other ornamental plants, the top sellers of P. lactiflora are those with red or pink flowers. However, most studies on flower colors have focused on the novel colors and have neglected the most common red flowers. In this study, a red cultivar of P. lactiflora ('Dafugui') and a pink cultivar ('Qingwen') were selected in order to study the discrepancy in the red color of the flowers. The results demonstrate that these two cultivars have the same compositions as anthocyanins, flavones, and flavonols but different contents. 'Dafugui' was found to have a high accumulation of upstream substances due to the higher expression of the early genes encoding phenylalanine ammonialyase (PlPAL) and flavonoid 3′-hydroxylase (PlF3′H). Moreover, the anthocyanidin synthase gene (PlANS) and UDP-glucose flavonoid 3-O-glucosyltransferase gene (PlUF3GT) encoding enzymes catalyze these upstream substances into anthocyanins, resulting in more redness in 'Dafugui' than in 'Qingwen'. Our study thus provides a better understanding of the anthocyanin accumulation and coloring mechanism of P. lactiflora and can serve as a theoretical basis for breeding more red flowers using genetic engineering techniques to cater to consumers' preferences. [ABSTRACT FROM AUTHOR]

Herbaceous peony (Paeonia lactiflora Pall.) is a well-known traditional flower in China and is widely used for landscaping and garden greening due to its high ornamental value. However, disease spots usually appear after the flowering of the plant and may result in the withering of the plant in severe cases. This study examined the disease incidence in an herbaceous peony field in the Yangzhou region, Jiangsu Province. Based on morphological characteristics and molecular data, the disease in this area was identified as a gray mold caused by Botrytis cinerea. Based on previously obtained transcriptome data, eight libraries generated from two herbaceous peony cultivars ‘Zifengyu’ and ‘Dafugui’ with different susceptibilities to the disease were then analyzed using digital gene expression profiling (DGE). Thousands of differentially expressed genes (DEGs) were screened by comparing the eight samples, and these genes were annotated using the Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) database. The pathways related to plant-pathogen interaction, secondary metabolism synthesis and antioxidant system were concentrated, and 51, 76, and 13 disease resistance-relevant candidate genes were identified, respectively. The expression patterns of these candidate genes differed between the two cultivars: their expression of the disease-resistant cultivar ‘Zifengyu’ sharply increased during the early stages of infection, while it was relatively subdued in the disease-sensitive cultivar ‘Dafugui’. A selection of ten candidate genes was evaluated by quantitative real-time PCR (qRT-PCR) to validate the DGE data. These results revealed the transcriptional changes that took place during the interaction of herbaceous peony with B. cinerea, providing insight into the molecular mechanisms of host resistance to gray mold. [ABSTRACT FROM AUTHOR]

Abstract: Herbaceous peony (Paeonia lactiflora Pall.) is an excellent landscape plant because of its great ornamental values. The objective of this study was to determine if plant growth and flower quality of P. lactiflora were affected by extreme pH in irrigation water. Compared with the control (pH 7.0), P. lactiflora exhibited a decrease in all morphological parameters except leaf number when irrigated with pH 4.0 and 10.0 waters. Physiological indices including chlorophyll a, chlorophyll b, chlorophyll a+b, soluble protein, malondialdehyde (MDA), soluble sugar, hydrogen peroxide (H2O2) and free proline were increased in response to irrigation with waters at pH 4.0 and 10.0, while the decline was occurred in chlorophyll a/b. Moreover, activities of three protective enzymes were also decreased in response to pH 4.0 and 10.0 treatments. These results indicated that the growth of P. lactiflora was significantly affected by extreme pH in irrigation water, and the most serious stress to P. lactiflora was caused under pH 10.0 treatment. Compared with plants irrigated with water at pH 7.0, 26.78% and 27.82% reduction were found in flower diameter and flower fresh weight of plants irrigated with water at pH 4.0. Likely, flower color fade under pH 4.0 treatment was attributed to decreased anthocyanin content and increased pH value of petal, which were coordinately regulated by nine anthocyanin biosynthetic genes and a vacuolar Na+/H+ antiporter1 gene (NHX1), respectively. The results would provide a theoretical guidance for the use of irrigation water in practical production of P. lactiflora. [Copyright &y& Elsevier]

Abstract: Herbaceous peony (Paeonia lactiflora Pall.) is a traditional Chinese flower, which has been expanded from the first garden cultivation to the cut flower cultivation. However, its weak mechanical strength of inflorescence stem severely restrains the quality of cut flowers. In this research, silicon was applied to enhance the mechanical strength of inflorescence stem, and the results revealed that 500μg/mL was the most effective silicon concentration. At this silicon concentration, related plant morphological indices including fresh weight and diameter of inflorescence stem, fresh weight and diameter of flower were all increased except plant height. Meanwhile, the layer number of thickened sclerenchyma cells and the thickness of cell walls were increased. Moreover, silicon application also increased lignin content of inflorescence stem, which might be the result of cooperative action of lignin biosynthesis genes. Additionally, silicon content of inflorescence stem was significantly increased under silicon application, which was mainly distributed in cortex and xylem. Consequently, the mechanical strength of inflorescence stem was enhanced. These results suggested that silicon application could enhance the mechanical strength of inflorescence stem and improve the cut flower quality in herbaceous peony. [Copyright &y& Elsevier]

Abstract: Herbaceous peony (Paeonia lactiflora Pall.) is an important ornamental plant used in urban green spaces, but little is known about whether it can grow in a shaded environment or understory. In this study, effects of shade on plant growth and flower quality in the herbaceous peony were investigated. The results showed that P. lactiflora morphology parameters, including plant height, leaf number, stem diameter, branch number, node number and plant crown width, were higher in plants grown with sun exposure compared to those grown in shade; however, opposite trends were observed for the top and middle leaf areas of the plant. Compared with sun exposure, shade decreased P. lactiflora photosynthetic capacity, light saturation point (LSP) and light compensation point (LCP) and increased the apparent quantum yield (AQY), mainly due to declined stomatal conduction (Gs). These decreases caused the soluble sugar, soluble protein and malondialdehyde (MDA) contents to decline, which led to delayed initial flowering date, prolonged flowering time, reduced flower fresh weight, increased flower diameter and faded flower color. Through cloning and expression analysis of anthocyanin biosynthetic genes, we determined that the fading of flower color was the result of reduced anthocyanin content, which was caused by the combined activity of anthocyanin biosynthesis genes and, in particular, of the upstream phenylalanine ammonialyase gene (PlPAL) and chalcone synthase gene (PlCHS). These results could provide us with a theoretical basis for further application of P. lactiflora in the greening of urban spaces and an understanding of the mechanisms behind the changes induced by shade. [Copyright &y& Elsevier]

Cyber-Physical Energy Systems (CPESs) are energy systems which rely on cyber components for energy production, transmission and distribution control, and other functions. With the penetration of Renewable Energy Sources (RESs), CPESs are required to provide flexible operation (e.g., load-following, frequency regulation) to respond to any sudden imbalance of the power grid, due to the variability in power generation by RESs. This raises concerns on the reliability of CPESs traditionally used as base-load facilities, such as Nuclear Power Plants (NPPs), which were not designed for flexible operation, and more so, since traditionally only hardware components aging and stochastic failures have been considered for the reliability assessment, whereas the contribution of the degradation and aging of the cyber components of CPSs has been neglected. In this paper, we propose a multi-state model that integrates the hardware components stochastic failures with the aging of cyber components, and quantify the unreliability of CPES in load-following operations under normal/emergency conditions. To show the application of the reliability assessment model, we consider the case of the Control Rod System (CRS) of a NPP typically used for a base-load energy supply. [ABSTRACT FROM AUTHOR]

Herbaceous peony (Paeonia lactiflora Pall.) is popular worldwide because of its gorgeous flower colour, and the yellow flower is the rarest. However, its mechanism of yellow formation is still unexplored from the post-translational level. In this study, the anatomy of the petal, cell sap pH and metal elements were investigated in bicoloured flower cultivar 'Jinhui' with red outer-petal and yellow inner-petal, and the yellow formation was influenced by the anatomy of petal, while not by the cell sap pH and metal elements. Subsequently, microRNAs sequencing (miRNA-seq) was used to identify small RNAs (sRNAs). A total of 4,172,810 and 3,565,152 specific unique sRNAs were obtained, 207 and 204 conserved miRNAs and 38 and 42 novel miRNAs were identified from red outer-petal and yellow inner-petal, respectively, which were confirmed by subcloning. Among these miRNAs, 163 conserved and 28 novel miRNAs were differentially expressed in two wheel of petals. And 5 differentially expressed miRNAs and their corresponding target genes related to yellow formation were screened, and their dynamic expression patterns confirmed that the yellow formation might be under the regulation of miR156e-3p-targeted squamosa promoter binding protein-like gene (SPL1). These results improve the understanding of miRNA regulation of the yellow formation in P. lactiflora. [ABSTRACT FROM AUTHOR]

Tree peony ( Paeonia suffruticosa Andr.) has been named the “king of flowers” because of its elegant and gorgeous flower colour. Among these colours, the molecular mechanisms of white formation and how white turned to red in P . suffruticosa is little known. In this study, flower colour variables, flavonoid accumulation and expression of flavonoid biosynthetic genes of white (‘Xueta’) and red (‘Caihui’) P . suffruticosa were investigated. The results showed that the flower colours of both cultivars were gradually deepened with the development of flowers. Moreover, two anthoxanthin compositions apigenin 7- O -glucoside together with apigenin deoxyheso-hexoside were identified in ‘Xueta’ and ‘Caihui’, but one main anthocyanin composition peonidin 3,5-di- O -glucoside (Pn3G5G) was only found in ‘Caihui’. Total contents of anthocyanins in ‘Caihui’ was increased during flower development, and the same trend was presented in anthoxanthins and flavonoids of these two cultivars, but the contents of these two category flavonoid in ‘Caihui’ were always higher than those in ‘Xueta’. Furthermore, nine structural genes in flavonoid biosynthetic pathway were isolated including the full-length cDNAs of phenylalanine ammonialyase gene ( PAL ), chalcone synthase gene ( CHS ) and chalcone isomerase gene ( CHI ), together with the partial-length cDNAs of flavanone 3-hydroxylase gene ( F3H ), flavonoid 3'-hydroxylase gene ( F3′H ), dihydroflavonol 4-reductase gene ( DFR ), anthocyanidin synthase gene ( ANS ), UDP-glucose: flavonoid 3-O-glucosyltransferase gene ( UF3GT ) and UDP-glucose: flavonoid 5-O-glucosyltransferase gene ( UF5GT ), and PAL , UF3GT and UF5GT were reported in P . suffruticosa for the first time. Their expression patterns showed that transcription levels of downstream genes in ‘Caihui’ were basically higher than those in ‘Xueta’, especially PsDFR and PsANS , suggesting that these two genes may play a key role in the anthocyanin biosynthesis which resulted in the shift from white to red in flowers. These results would provide a better understanding of the underlying molecular mechanisms of flower pigmentation in P . suffruticosa . [ABSTRACT FROM AUTHOR]