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Overexpression of acdS in petunia negatively affects seed germination by suppression of ethylene biosynthesis and signaling genes and induction of abscisic acid biosynthesis genes in the seeds. The acdS gene, which encodes 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, has been overexpressed in horticultural crops to improve their tolerance to abiotic stress. However, the role of acdS in the germination of crop seeds has not been investigated, despite its suppression of ethylene production. In this study, acdS overexpression significantly reduced seed weight and germination rate in transgenic petunia cv. Merage Rose (T5, T7, and T12) relative to wild type via the suppression of ethylene biosynthesis and signaling genes and induction of abscisic acid (ABA) biosynthesis genes. The germination rate of T7 was significantly lower than those of T5 and T12, which was linked to higher expression of acdS in the former than the latter. The addition of exogenous ACC and gibberellic acid (GA

The C2H2 zinc finger proteins (ZFPs) play essential roles in regulating cold stress responses. Similarly, raffinose accumulation contributes to freezing stress tolerance. However, the relationship between C2H2 functions and raffinose synthesis in cold tolerance remains uncertain. Here, we report the characterization of the cold-induced C2H2-type zinc finger protein PhZFP1 in Petunia hybrida. PhZFP1 was found to be predominantly localized in the nucleus. Overexpression of PhZFP1 conferred enhanced cold tolerance in transgenic petunia lines. In contrast, RNAi mediated suppression of PhZFP1 led to increased cold susceptibility. PhZFP1 regulated the expression of a range of abiotic stress responsive-genes including genes encoding proteins involved in reactive oxygen species (ROS) scavenging and raffinose metabolism. The accumulation of galactinol and raffinose, and the levels of PhGolS1-1 transcripts, were significantly increased in PhZFP1-overexpressing plants and decreased in PhZFP1-RNAi plants under cold stress. Moreover, the galactinol synthase (GolS)-encoding gene PhGolS1-1 was identified as a direct target of PhZFP1. Taken together, these results demonstrate that PhZFP1 functions in cold stress tolerance by modulation of galactinol synthesis via regulation of PhGolS1-1. This study also provides new insights into the mechanisms underlying C2H2 zinc finger protein-mediated cold stress tolerance, and has identified a candidate gene for improving cold stress tolerance.

Calibrachoa Cerv., Fabiana Ruiz & Pav., and Petunia Juss. form a clade within tribe Petunieae (Solanaceae). Phylogenetic studies of Petunieae, either as part of a family-wide analysis or focusing on the genera Calibrachoa and Petunia, have either left Fabiana unsampled or included only a single species. These studies have found conflicting relationships among the three genera with all three possible topologies obtained. Petunia patagonica (Speg.) Millán, originally described in the genus Nierembergia Ruiz & Pav., is morphologically distinct within Petunia and geographically disjunct from other members of the genus. For the first time, in this study we include multiple species of Fabiana, Calibrachoa, and Petunia, including P. patagonica. Using three chloroplast DNA regions and the nuclear gene GBSSI, or “waxy,” our results provide strong support for a sister group relationship between Calibrachoa and Fabiana and for the placement of P. patagonica within Fabiana. Since there is already a species Fabiana patagonica Speg., we provide the new name Fabiana australis Alaria nom. nov. to replace Petunia patagonica.

Microbial biostimulants can promote ornamental plant growth during production and improve crop performance under abiotic stresses. Even though biostimulants have shown potential in many agricultural applications, the effectiveness and specificity of many products are not well understood. The objective of this study was to analyze the growth-promoting effects of microbial biostimulants during the greenhouse production of floriculture crops. We evaluated 13 biostimulant products in greenhouse-grown zinnia (Zinnia elegans ‘Magellan Ivory’) and petunia (Petunia ×hybrida ‘Carpet White’) at low fertility (one-third of the optimal fertilizer concentration). Biostimulant products 1 and 2 containing multiple species of beneficial bacteria and fungi, and product 10 containing Bacillus subtilis QST 713, were found to increase various aspects of plant growth, including the growth index, leaf chlorophyll content (SPAD index), and shoot biomass. Both flower biomass and numbers were greater in petunia treated with product 1, and leaf size increased in zinnia treated with products 1, 2, and 10. Plants treated with these effective biostimulants at low fertility had similar or better growth and quality than untreated plants grown under optimal fertility. The concentration of various nutrient elements in leaves was higher in zinnia plants treated with biostimulant products 1, 2, or 10 compared with the negative control. Some putative mechanisms for biostimulant effectiveness, the possible reasons for biostimulant ineffectiveness, and the potential for using biostimulants as a sustainable cultural strategy are discussed. This study provides useful information about microbial biostimulant effectiveness, which is important for the development and utilization of biostimulants in the greenhouse production of floriculture plants.

To investigate whether low-level lighting is necessary and which narrow-band light spectra are effective in seed germination, seeds of 14 genotypes from begonia (Begonia × tuberosa), echinacea (Echinacea spp.), gerbera (Gerbera jamesonii), petunia (Petunia × hybrida), and vinca (Catharanthus roseus) were germinated under ultraviolet-B (UVB), blue (B), green (G), red (R), far-red (FR) light, or darkness. Light-emitting diode (LED) fixtures provided all spectrum treatments except for UVB, which was provided by a narrow-band fluorescent light. The photon flux density at seed level was ≈18 μmol·m−2·s−1 for B, G, R, and FR, and 0.4 μmol·m−2·s−1 for UVB. Based on daily germination observations, final germination percentage, germination onset time, germination time spread, and germination speed were compared among different spectrum treatments for each of the plant genotypes. There were no promotive effects on final germination percentage, germination onset time, and germination time spread under the narrow-band lights compared with darkness. For all plant genotypes, B had a similar effect as darkness on seed germination. FR inhibited seed germination relative to darkness by reducing final germination percentage by 31%–88%, delaying germination onset time by 30%–40%, and decreasing germination speed by 11%–48% in some genotypes. Under R, G, and UVB compared with darkness, germination speed was promoted for begonia ‘Apricot Shade’, a light-requiring genotype, and inhibited for vinca ‘Burgundy’, a light-inhibited genotype. Therefore, lighting at low levels used in our study is unnecessary for seed germination of the tested species except light-requiring genotypes, where R, G, and UVB are the most promotive among the tested narrow-band lights.

Seaside petunia (Calibrachoa parviflora) is a mat-forming plant species that was recently reported in fall-seeded onion (Allium cepa) in the southwestern United States. To initiate development of herbicide recommendations for seaside petunia in onion, we conducted a study to determine seaside petunia susceptibility to commonly used herbicides for broadleaf weed control after onion emergence. Our study included herbicides applied at below-label rates, which provided insights on seaside petunia responses to reductions in the amount of herbicide available for plant absorption. For herbicides with preemergence activity, our growth chamber study indicated that soil applications of flumioxazin or oxyfluorfen (0.06 and 0.25 lb/acre, respectively) prevented seaside petunia seedling emergence when applied at 0.125×, 0.25×, 0.5×, and 1.0× the labeled rates for onion. Labeled rate treatments of dimethenamid-P (0.84 lb/acre) and S-metolachlor (0.64 lb/acre) inhibited seedling emergence similar to labeled rate treatments of flumioxazin and oxyfluorfen; however, below-label rate treatments of dimethenamid-P and S-metolachlor resulted in diminished control of seaside petunia compared with the labeled rate treatments. Following labeled rate applications of dimethyl tetrachloroterephthalate [DCPA (6 lb/acre)] and pendimethalin (0.71 lb/acre), more than 50% of seaside petunia seedlings emerged compared with the nontreated control. For herbicides with postemergence activity on weeds, our greenhouse study indicated that bromoxynil at 0.37 lb/acre, flumioxazin at 0.06 lb/acre, and oxyfluorfen at 0.25 lb/acre equally reduced growth of seaside petunia plants that were small at the time of spraying (stem length, 1–2 cm). Postemergence control of seaside petunia with oxyfluorfen and flumioxazin decreased as plant size at spraying increased; however, bromoxynil effects on seaside petunia remained high as stem length at spraying increased from 5 to 12 cm. Based on the results of this study, we conclude that promising herbicide programs for seaside petunia in onion include oxyfluorfen or flumioxazin for preemergence control and bromoxynil for postemergence control. These herbicides, alone and in combination, should be evaluated for seaside petunia control and onion phytotoxicity in future field trials.

An R2R3-MYB transcription factor, CmMYB9a, activates floral coloration in chrysanthemum by positively regulating CmCHS, CmDFR and CmFNS, but inhibiting the expression of CmFLS. Chrysanthemum is one of the most popular ornamental plants worldwide. Flavonoids, such as anthocyanins, flavones, and flavonols, are important secondary metabolites for coloration and are involved in many biological processes in plants, like petunia, snapdragon, Gerbera hybrida, as well as chrysanthemum. However, the metabolic regulation of flavonoids contributing to chrysanthemum floral coloration remains largely unexplored. Here, an R2R3-MYB transcription factor, CmMYB9a, was found to be involved in flavonoid biosynthesis. Phylogenetic analysis and amino acid sequence analysis suggested that CmMYB9a belonged to subgroup 7. Transient overexpression of CmMYB9a in flowers of chrysanthemum cultivar 'Anastasia Pink' upregulated the anthocyanin-related and flavone-related genes and downregulated CmFLS, which led to the accumulation of anthocyanins and flavones. We further demonstrated that CmMYB9a independently activates the expression of CmCHS, CmDFR and CmFNS, but inhibits the expression of CmFLS. Overexpression of CmMYB9a in tobacco resulted in increased anthocyanins and decreased flavonols in the petals by upregulating NtDFR and downregulating NtFLS. These results suggest that CmMYB9a facilitates metabolic flux into anthocyanin and flavone biosynthesis. Taken together, this study functionally characterizes the role of CmMYB9a in regulating the branched pathways of flavonoids in chrysanthemum flowers.

Editing of ACO genes involved in ethylene biosynthesis pathway reduces ethylene production in petunia seeds and inhibits seed germination. Ethylene production in the seeds of Petunia hybrida cv. ‘Mirage Rose’ was associated with expression of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO) genes (PhACO1, PhACO3, and PhACO4). Suppression of their expression by ethylene inhibitor silver thiosulphate (STS) significantly reduced ethylene production and inhibited seed germination. When it was combined with ethylene precursor ACC, ethylene production was re-promoted via activation of the genes and higher seed germination was restored. This was confirmed using the mutants editing the genes and WT. In the present study, compared with wild type plants, three different mutants (phaco1, phaco3, and phaco4) showed significantly decreased germination percentages as well as delayed germination time and seedling growth. These reductions were associated with lighter seed weight, lower ACO transcript levels, and lower ethylene production in mutants. Inhibited seed germination owing to reduced ethylene production was further verified by the supplementation of exogenous ACC and gibberellic acid (GA3) to growth medium, which restored high seed germination activity in all mutants via enhanced ethylene production. In this study, we reported a key regulatory role of ethylene in seed germination mechanisms in petunia. Further, we highlighted on need to consider the negative effects of ethylene reduction in seed germination and plant growth when editing genes in the ethylene biosynthesis pathway for the maintenance of postharvest fruit, vegetable, and flower quality.

Since co-suppression was discovered as a pioneer silencing phenomenon of RNA interference (RNAi) in petunia in 1990, many types of small RNAs have been identified in the RNAi pathway among various eukaryotes. In plants, a large number of 21- or 24-nucleotide (nt) phased small interfering RNAs (phasiRNAs) are produced via processing of long RNA precursors by Dicer-like proteins. However, the roles of phasiRNAs remain largely unknown. The development of imaging technology and RNA profiling has clarified the spatiotemporal regulation of phasiRNAs, and subsequently the different functions of 21-nt trans-acting phasiRNAs and 24-nt cis-regulatory phasiRNAs during male organ development. This review focuses on the biogenesis, diversification, spatiotemporal expression pattern and function of phasiRNAs in plants.

Anthocyanins are important pigments in plants and glycosylation plays an important role in the stability of anthocyanins. Anthocyanin 5-O-glucosyltransferase (5GT) can glycosylate anthocyanin at the 5-O-position. Till now, the enzymatic activity characteristics of 5GT had been studied in vitro in a variety of plants. However, the subcellular localization of 5GT protein still remained unclear, and little genetic evidence on the roles of 5GT in plants has been reported. The full-length Ph5GT gene from petunia (Petunia hybrida) was isolated in this study. Green fluorescent fusion protein assays revealed that Ph5GT protein was localized to the cytoplasm. Ph5GT was found to be highly expressed in flowers, with highest levels of expression occurring during the coloring stage of flower development. Furthermore, Ph5GT silencing led to the change in flower color from purple to light purple and a significant reduction in total anthocyanin content. The metabolome analysis revealed that the content of malvidins and petunidins modified by glycosylation at the 5-O-position was significantly reduced, while the content of their precursor without glycosylation was significantly increased, implying that Ph5GT could glycosylate malvidin and petunidin derivatives and that the substrate types of Ph5GT were expanded in comparison to previous studies.

Petunia is one of the world’s most important flowers, and its branch development has long been a source of discussion. MYB transcription factors have been identified as important plant branching regulators. In this study, 113 R2R3-MYB genes were identified from the petunia genome. PhMYB genes, closely related to RAXs, were expressed at greater levels in axillary buds and roots. Decapitation and 6-BA did not regulate the expression of PhMYB37. PhMYB37 was localized in the nucleus. Heterologous overexpression of PhMYB37 promoted shoot branching in transgenic Arabidopsis while silencing of PhMYB37 inhibited shoot branching. These results suggest that PhMYB37 plays a critical and positive role in petunia shoot branching.

The role of

Protein acetylation and crotonylation are important posttranslational modifications of lysine. In animal cells, the correlation of acetylation and crotonylation has been well characterized and the lysines of some proteins are acetylated or crotonylated depending on the relative concentrations of acetyl-CoA and crotonyl-CoA. However, in plants, the correlation of acetylation and crotonylation and the effects of the relative intracellular concentrations of crotonyl-CoA and acetyl-CoA on protein crotonylation and acetylation are not well known. In our previous study, PaACL silencing changed the content of acetyl-CoA in petunia (Petunia hybrida) corollas, and the effect of PaACL silencing on the global acetylation proteome in petunia was analyzed. In the present study, we found that PaACL silencing did not significantly alter the content of crotonyl-CoA. We performed a global crotonylation proteome analysis of the corollas of PaACL-silenced and control petunia plants; we found that protein crotonylation was closely related to protein acetylation and that proteins with more crotonylation sites often had more acetylation sites. Crotonylated proteins and acetylated proteins were enriched in many common Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. However, PaACL silencing resulted in different KEGG pathway enrichments of proteins with different levels of crotonylation sites and acetylation sites. PaACLB1-B2 silencing did not led to changes in the opposite direction in crotonylation and acetylation levels at the same lysine site in cytoplasmic proteins, which indicated that cytoplasmic lysine acetylation and crotonylation might not depend on the relative concentrations of acetyl-CoA and crotonyl-CoA. Moreover, the global crotonylome and acetylome were weakly positively correlated in the corollas of PaACL-silenced and control plants.

Golovinomyces longipes is a widespread powdery mildew on Solanaceae (Nicotiana, Petunia and Solanum spp.). In the past, it has been reported only once on Verbena (Verbenaceae), a non-solanaceaous host. Recently, this powdery mildew has been found on the composite Matricaria chamomilla. The identification of the powdery mildew species on this unusual host has been proved by morphological studies and DNA sequence analysis. Both datasets coincide with the characteristic data for G. longipes on Solanaceae. First inoculation experiments with further composites resulted in an infection of Brachyscome hybrid ‘Surdaisy’. To our knowledge, this is the first report of G. lonigpes on hosts belonging to the important family of Asteraceae and an additional proof of the broader host range of G. longipes beyond the Solanaceae.

The overall goal was to evaluate fertilizer options for greenhouse producers, with or without a plant growth regulator (PGR) application, to improve subsequent performance of container-grown annuals. Petunia (Petunia × hybrida) was the model container-grown crop in simulated production and consumer environments. The first experiment at two locations (New Hampshire and Florida) compared strategies using water-soluble fertilizer [WSF (17N–1.8P–14.1K)], controlled-release fertilizers (CRF), and slow-release fertilizers (SRF) that were either applied throughout or at the end of the 8-week production phase [point of shipping (POS)] for petunia rooted cuttings grown in 8-inch azalea containers. In the subsequent simulated “consumer” phase, container plants were irrigated with clear water (no fertilizer) for 6 weeks. Plant performance [number of flowers, SPAD chlorophyll index, dry weight, and tissue nitrogen (N)] at the end of the consumer phase was improved by top-dressing at POS with either CRF or granular organic fertilizer (both at 2.74 g/container N), or preplant incorporation of either a typical CRF at 4.12 g/container N or a CRF with an additional prill coating to delay initial release (DCT) at 2.74 g/container. There was no carry-over benefit from applying a liquid urea-chain product (1.37 or 2.74 g/container N) or top dressing with granular methylene di-urea (2.74 g/container N), or 400 mg·L–1 N (0.2 g/container N) from a liquid organic fertilizer at POS. The consumer benefit of applying 400 mg·L–1 N (0.2 g/container N) from a WSF at POS was increased by supplementing with 235 mg·L–1 magnesium (Mg) and 10 mg·L–1 iron (Fe). A second experiment in 10-inch-diameter pots evaluated the effect on consumer performance from providing 200 or 400 mg·L–1 N of WSF with the PGR paclobutrazol, at the final 1 L/pot irrigation at POS. Application of 3 mg·L–1 paclobutrazol delayed leaf yellowing and reduced plant height, width, and shoot dry weight during the consumer phase, resulting in a more compact growth habit and higher plant quality compared with plants that received no PGR, regardless of WSF treatment. Addition of supplemental 235 mg·L–1 Mg and 10 mg·L–1 Fe to the high rate of WSF and PGR did not improve consumer performance compared with other treatments that included a PGR. Overall, the first experiment demonstrated that the most effective fertilizer strategies require a CRF or SRF that will release nutrients throughout the consumer phase, and that impact of liquid fertilizer options is limited because of lower N supply per container. A single application at POS of a high rate of WSF with supplemental Mg and Fe may have short-term benefits, for example while plants are in a retail environment. Growers should consider combining a residual fertilizer with a PGR application for premium, value-added container annuals.

Anthocyanins, vital metabolites in plants, are formed by anthocyanidins combined with various monosaccharides, including glucose, rhamnose, and arabinose. Rhamnose contributes greatly to the glycosylation of anthocyanidins. There are two kinds of rhamnose synthase (RS): rhamnose biosynthesis (RHM), and nucleotide-RS/epimerase-reductase (UER1). Nevertheless, no RS isoform was reported to be involved in anthocyanin synthesis. Here, three homologous PhRHM genes, namely PhRHM1, PhRHM2, and PhRHM3, and one PhUER1 gene from petunia were cloned and characterized. Green fluorescent protein fusion protein assays revealed that PhRHMs and PhUER1 are localized in the cytoplasm. We obtained PhRHM1 or/and PhRHM2 or PhUER1 silenced petunia plants and did not attempt to obtain PhRHM3 silenced plants since PhRHM3 mRNA was not detected in petunia organs examined. PhRHM1 and PhRHM2 (PhRHM1-2) silencing induced abnormal plant growth and decreased the contents of l-rhamnose, photosynthetic pigments and total anthocyanins, while PhUER1 silencing did not cause any visible phenotypic changes. Flavonoid metabolome analysis further revealed that PhRHM1-2 silencing reduced the contents of anthocyanins with rhamnose residue. These results revealed that PhRHMs contribute to the biosynthesis of rhamnose and that PhRHMs participate in the anthocyanin rhamnosylation in petunia, while PhUER1 does not.

To evaluate the natural occurrence of the plant growth-promoting bacterium Azospirillum brasilense and petunia plants, local strains were isolated and characterized by biochemical and molecular methods. Three strains were assessed in greenhouse conditions using Petunia × hybrida Ultra™. Treatments: Plants without bacterial inoculation or chemical fertilization; fertilized with NPK and KNO3 ; and independently inoculated with the strains 2A1, 2A2, and 2E1 by submerging their roots in a bacterial suspension (~106 CFU·ml-1 ). Root length, dry weight of roots and shoots, leaf area, leaf greenness, and nutrient content were evaluated. The number of days from transplanting to the opening of the first flower and the number of flowers per plant were also determined. As a result, five isolates were characterized as A. brasilense, showing the capacity to produce indoles and siderophores, to solubilize phosphate, nitrogenase activity, and nifH-PCR amplification. In general, all the parameters of the plant assay were improved in plants inoculated with A. brasilense, with variations among the strains, as well as the onset of flowering and the number of flowers per plant, compared with uninoculated or fertilized plants. This is the first report on the natural occurrence of A. brasilense in petunia with the capacity to improve plant growth and flowering.

Mineral nutrients are necessary for the growth and development of plants. Previous studies have concentrated mainly on silicon-accumulating plants, while less work has been conducted on non-accumulating plants such as Petunia × atkinsiana D. Don. In this study, we investigated the responses of morphological (plant height, root length, fresh and dry weight, no. of flowers) and biochemical (proline, malondialdehyde MDA, catalase CAT activity, total chlorophylls, carotenoids, total polyphenol, and NO3) traits of petunia to external application of commercial silicon solution (Hydroplus™ Actisil) after 5 weeks of in vitro culture and 6 weeks under greenhouse condition. Actisil was supplemented into the MS medium (in vitro) at concentrations of 0 (control), 50, 100, 200, and 500 mg L−1, or supplied via irrigations at a concentration of 0 (control) and 200 mg L−1 in one, two, and three applications under greenhouse conditions. The addition of silicon to the MS medium decreased plant height (22–41% of control) and root length (53–70% of control). In contrast, in greenhouse-grown petunia irrigation of silicon increased plant height (145% of control ) and root length (176% of control). Petunias treated with Actisil had greener leaves compared to the control. This was also confirmed by higher concentrations of chlorophyll. Conversely, increased concentrations of proline, MDA, and total polyphenol and higher CAT activities may indicate that silicon provokes a stress response of the in vitro plants. Actisil treatment in the concentration of 200 mg L−1 was found to positively affect the growth and flowering of the greenhouse-grown petunia. Actisili application in vitro may provoke a stress response of the Petunia × atkinsiana D. Don. plantlets, but under greenhouse the concentration of 200 mg L−1 positively affected the growth and flowering of petunia.

The amount of fertilizer applied during the commercial production of bedding plants has decreased in recent years because of increasing concerns about environmental impacts and the need to minimize production costs. However, reduced fertilization affects plant growth and flowering during production and in the postproduction environment. Plants grown with lower nutrient levels may perform satisfactorily during greenhouse production, but they may possess insufficient nutrients to sustain further growth in the postproduction environment, where fertilizer application is frequently lacking. This study examined conventional and alternative fertilizer delivery strategies that produce high-quality petunia (Petunia ×hybrida) during greenhouse production and continue to support plant growth and flowering in the postproduction environment. The fertilizer treatments during production consisted of four constant liquid fertilization (CLF) treatments of 0, 50, 100, or 200 ppm nitrogen (N) and three controlled-release fertilization (CRF) treatments (0, 4, or 8 lb/yard3). Three pulse fertilization (PF) treatments (0, 300, or 600 ppm N) were applied immediately before moving the plants to the postproduction environment. During production, petunia growth and development increased as CLF increased from 0 to 200 ppm N, but the addition of CRF resulted in the increase occurring at a declining rate. During postproduction, the interactive effects of CLF and CRF continued in a similar pattern as that seen in the production environment. The additional PF treatments resulted in further increases in plant growth. Across all CLF and CRF treatments, the leaf area increased from 466 to 540 cm2 as PF increased from 0 to 300 ppm N, and the leaf area increased further to 631 cm2 as PF increased from 300 to 600 ppm N. Based on our findings, two alternative strategies are possible. First, 0 to 50 ppm N CLF can be combined with 4 lb/yard3 CRF. The second strategy maintains the standard commercial practice of applying 100 ppm N CLF treatment and then applying a 300- to 600-ppm N PF treatment. These results suggest that a relatively low CLF rate can be used to achieve the desired production characteristics while reducing the cost of plant growth regulation, and that additional plant nutrition can be provided with CRF and/or PF to enhance the postproduction performance.

miR156/157 plays multiple pivotal roles during plant growth and development. In this study, we identified 11 miR156- and 5 miR157-encoding loci from the genome of Petunia axillaris and Petunia inflata, designated as PaMIR0156/157s and PiMIR0156/157s, respectively. Real-time quantitative reverse transcription PCR (qRT-PCR) analysis indicated that PhmiR156/157 was expressed predominantly in cotyledons, germinating seeds, flower buds, young fruits and seedlings. PhmiR156/157 levels declined in shoot apical buds and leaves of petunia before flowering as the plant ages; moreover, the temporal expression patterns of most miR156/157-targeted PhSPLs were complementary to that of PhmiR156/157. Ectopic expression of PhMIR0157a in Arabidopsis and petunia resulted in delayed flowering, dwarf plant stature, increased branches and reduced organ size. However, PhMIR0156f-overexpressing Arabidopsis and petunia plants showed only delayed flowering. In addition, downregulation of PhmiR156/157 level by overexpressing STTM156/157 led to taller plants with less branches, longer internodes and precocious flowering. qRT-PCR analysis indicated that PhmiR156/157 modulates these traits mainly by downregulating their PhSPL targets and subsequently decreasing the expression of flowering regulatory genes. Our results demonstrate that the PhmiR156/157-PhSPL module has conserved but also divergent functions in growth and development, which will help us decipher the genetic basis for the improvement of flower transition, plant architecture and organ development in petunia.

This study aimed to evaluate the seedlings growth of Petunia x hybridaand Gomphrena globosaat different times and substrates based on agricultural residues. A completely randomized experimental design was adopted, in a factorial scheme, with treatments consisting of four replications and the experimental unit formed by ten plants. The flower species Petunia x hybridaand G. globosawere cultivated in five substrate compositions and in two seasons, with sowing carried out in April and June for Petunia x hybridaand April and October for G. globosa. The substrates were composed using commercial substrate (CM), bovine manure (BM), worm humus (WM) and rice husk ash (HA), in volumetric proportions: (S1) 100% CS; (S2) 40% CS + 20% BM + 20% WH + 20% HA; (S3) 60% CS + 20% WH + 20% HA; (S4) 60% CS + 20% BM + 20% HA; and (S5) 80% CS + 20% BM. Emergence, emergence speed index, height, number of leaves, length of the largest leaf, length of the largest root, dry mass of the aboveground part, dry mass of the root system and total dry mass were evaluated. The seedlings growth of the Petunia x hybridaand G. globosachanged according to the characteristics of the substrates and the growing seasons. The substrate composed with 80% commercial substrate and 20% bovine manure showed similar or superior results to the commercial substrate and can be used in order to reduce production costs without prejudice to the seedlings growth. The cultivation of Petunia x hybridain April resulted in seedlings with greater height, leaf length and greater accumulation of phytomass. The G. globosa seedlings showed greater development of the aboveground part and the root system, in addition to greater accumulation of phytomass when cultivated in October.

Plants respond to water deficit through several mechanisms. Among which, plant hormones play an important role in induction to abiotic stress tolerance. To bring this issue closer, an experiment was conducted to examine whether salicylic acid (SA) and gibberellic acid (GA3) exogenous applications through foliar spray could alleviate detrimental effects of water deficit on Persian petunia. Treatments consisted of water stress in three levels: 100% field capacity (F.C.) as control, 50, and 25% F.C linked with different concentrations of GA3 and SA sprayed at four levels (0, 100, 200 and 300 mg L–1). Results showed that the dry and fresh biomass, leaf area, photosynthetic pigments levels, relative water content (RWC) and the total number of flowers were significantly (P≤0.01) reduced in response to water deficit. However, free proline concentration and root-to-shoot ratio significantly increased in stressed plants. Plants subjected to severe water stress (25% F.C.), exhibit about 66% stomatal conductance rate lower than the plants grown at 100% F.C. The results showed that SA-treated plants exhibited reduced negative effect of water stress on most of the qualitative and quantitative attributes compared to control, while GA3 application had little impact on studied traits. Importantly, stomatal conductance and RWC were improved in water-stressed plants treated with SA. Moreover, SA-treated plants produced more flowers at all water deficit levels compared to GA3 sprayed plants. It can be concluded that Persian petunia plants respond to water deficit through adaptive changes at biochemical and morphological levels and that adverse effects of water deficit could be alleviated by exogenous application of SA.

Under light-limiting conditions, many ornamental greenhouse-grown plants show undesired morphological characteristics, such as plant elongation (hypocotyl and epicotyl length) and low dry mass, which reduce plant quality. Research has shown that use of plant growth regulators (PGRs) and changes in both light intensity and spectral composition can reduce these undesired characteristics. However, little is known about the role of the combined effects of supplemental lighting and PGRs on the production of ornamental seedlings. The objective of this study was to characterize the combined and independent effects of light intensity, spectral composition, and PGR applications on the greenhouse production of ornamental transplants. Petunia (Petunia × hybrida), geranium (Pelargonium × hortorum), pansy (Viola × wittrockiana) and dianthus (Dianthus chinensis) were grown for 32–42 days under three supplemental light (SL) treatments: 1) high-pressure sodium (HPS), 2) light-emitting diodes (LEDs) with a 6 blue (B):5 green (G):89 red (R) (percent photon flux ratio), and 3) LEDs with 19B:81R (100 μmol m−2 s−1, 18 h photoperiod for all treatments). A control (No SL) was also included. In addition, a portion of plants were also sprayed with the paclobutrazol PGR (PBZ and No PBZ). The synergistic effects of the combination of PBZ and supplemental lighting resulted in the most compact plants, caused by a reduction in plant height by PBZ and an increase in dry mass by SL. However, PBZ reduced shoot dry mass of most plant species and light combinations. Plant compactness was greater under the 6B:5G:89R LED composition for petunia and when combined with PBZ for geranium than for plants under HPS lighting. Root dry mass of petunia, geranium, and pansy plants increased in response to SL compared with no SL by 2.4–5.7-fold. Results from the two LED spectra were unexpected; plants under 6B:5G:89R were more compact (petunia, geranium), had higher anthocyanin concentrations (petunia), were shorter (petunia, pansy, dianthus) and had less leaf area (petunia, pansy, dianthus) than plants in the SL treatment with a higher B and lower G PF (19B:81R). Supplemental lighting and PBZ can be used in conjunction or independently to improve plant morphology. The increased light from SL provided the most benefits by improving dry mass, compactness, and leaf number for most plant species. However, when PBZ was used in combination with SL, plant compactness increased for some species. The spectral composition of SL had an impact on plant growth and morphology, warranting additional research on plant responses to small changes in the spectral composition of SL.

MicroRNA319 (miR319) plays an important role in leaf development. Although leaf discs are frequently used for plant transformation, little is known about the function of miR319 in shoot regeneration from leaf explants. To investigate the role of miR319 in de novo shoot organogenesis from leaf explants, the MIR319 gene was overexpressed in petunia (Petunia × hybrida), under the control of the 35S promoter. Petunia leaves overexpressing miR319 (miR319-OX) showed several morphological abnormalities, such as rounded, uneven, and curled leaf blade, larger leaf size, and smaller and rounded abaxial surface cells, which were differences compared to wild-type (WT) leaves. Additionally, miR319-OX leaf explants demonstrated enhanced shoot organogenesis on a growth medium containing 6-benzylaminopurine (BA) at shoot-inducing concentrations, and cytokinin-independent shoot regeneration on hormone-free medium compared with WT explants. Quantitative real-time PCR (qRT-PCR) analysis indicated that the expression of petunia NO APICAL MERISTEM (PhNAM) and SHOOT MERISTEMLESS (PhSTM) genes was markedly increased in miR319-OX explants compared with WT explants under shoot induction conditions, whereas the expression of petunia cytokinin-responsive type-A response regulator genes, PhRR2 and PhRR3, showed no differences in expression between WT and miR319-OX leaf explants. These results suggest that miR319 regulates the formation of shoot meristems from leaf explants in petunia during in vitro culture.

Detection and identification of yellow mosaic stunt disease on Petunia sp. using nested PCR method. Yellow mosaic stuntdisease was found at some nurseries of Petunia in Sleman, Yogyakarta, also in Muntilan and Magelang Central Java. Thedisease was very important due to its ability reducing the quality and quantity of Petunia seedlings. The causal agent of thedisease may be carried over to imported seeds and necessary to identify as a basic information for developing controlstrategies. This research was done by mechanical transmission on indicator plants. The observation of the causal agents wasconducted using electron microscope with quick dipping method and the molecular detection was done using nested PCRwith TobRT up1-TobRT do2 as the external primers and TobN up3-TobN do4 as the internal primers. Mechanical inoculationshowed chlorosis symptoms that developed into local spot on Chenopodium amaranticolor as well as mosaic and veinbanding on Nicotiana benthamiana. The observation using electron microscope showed rod-shaped virus particles sizedapproximately 300 nm and by PCR method produced around 568 bp and 400 bp DNA band. Based on the sequence analysis,the disease was caused by Rehmania mosaic virus. This type of Tobamovirus has 96% similarity with ReMV-Japan. ReMV, aplant pathogen which was a member of Tobamovirus that has never been reported in Indonesia. This research was the firstreport of ReMV in Indonesia infecting Petunia as ornamental plant.

Arbuscular mycorrhiza fungi (AMF) are beneficial soil fungi that can promote the growth of their host plants. Accurate quantification of AMF in plant roots is important because the level of colonization is often indicative of the activity of these fungi. Root colonization is traditionally measured with microscopy methods which visualize fungal structures inside roots. Microscopy methods are labor-intensive, and results depend on the observer. In this study, we present a relative qPCR method to quantify AMF in which we normalized the AMF qPCR signal relative to a plant gene. First, we validated the primer pair AMG1F and AM1 in silico, and we show that these primers cover most AMF species present in plant roots without amplifying host DNA. Next, we compared the relative qPCR method with traditional microscopy based on a greenhouse experiment with Petunia plants that ranged from very high to very low levels of AMF root colonization. Finally, by sequencing the qPCR amplicons with MiSeq, we experimentally confirmed that the primer pair excludes plant DNA while amplifying mostly AMF. Most importantly, our relative qPCR approach was capable of discriminating quantitative differences in AMF root colonization and it strongly correlated (Spearman Rho = 0.875) with quantifications by traditional microscopy. Finally, we provide a balanced discussion about the strengths and weaknesses of microscopy and qPCR methods. In conclusion, the tested approach of relative qPCR presents a reliable alternative method to quantify AMF root colonization that is less operator-dependent than traditional microscopy and offers scalability to high-throughput analyses.

The present experiment was carried out in winter season at 2020 in the Research Field, Department of Horticulture, SHUATS, Prayagraj. The experiment was conducted in Randomized Block Design (RBD), with eight treatments, replicated thrice with growing media (Cocopeat + Perlite + Vermicompost) on Petunia. From the present experimental findings it is found that treatment T7 (Cocopeat, perlite, vermicompost, 2:2:1) was found best in terms of growth parameters followed by T3 (Cocopeat, perlite, vermicompost (1:2:1) and T4 (Cocopeat, perlite, vermicompost (1:2:2).In earliness parameters T6 (Cocopeat, perlite, vermicompost (2:1:2) was best followed by T7(Cocopeat, perlite, vermicompost (2:2:1) found superior. In terms of flowering and yield parameters treatment T5 (Cocopeat, perlite, vermicompost (2:1:1) was superior followed by T3 Cocopeat, perlite, vermicompost (1:2:1) and T7 (Cocopeat, perlite, vermicompost (2:2:1). Minimum vegetative growth and no flowering and fruiting were recorded in control.

Ferredoxin-thioredoxin reductase (FTR) is an iron-sulfur protein that supplies electrons from photochemically reduced ferredoxin (Fd) to thioredoxin (Trx) in the ferredoxin/thioredoxin system in chloroplasts. The FTR is a heterodimer with a variable subunit (FTRv) and a catalytic subunit (FTRc). The function of FTRv is not well known. In petunia (Petunia hybrida), FTRv is a single-copy gene, which is named PhFTRv. In this study, the spatio-temporal expression of PhFTRv in petunia was analyzed, and PhFTRv transcription was found to be high in leaves and stems. A tobacco rattle virus gene silencing was used in this study. Virus induced gene silencing-mediated PhFTRv silencing resulted in large yellow-green leaves, delayed flowering, and reduced cold tolerance in petunia plants.

Hybridization between closely related plant species is a widespread phenomenon with significant evolutionary consequences, so natural hybrid zones provide exciting opportunities to study the processes of genetic differentiation and species formation. In Petunia, genetics, ecology and evolution of pollination syndromes have been thoroughly studied and related to the development of prezygotic isolation barriers between species. However, to date, no studies have explored the importance of extrinsic post-zygotic barriers such as environmental selection as drivers of reproductive isolation. In this study, we applied a population genetics approach to understand the speciation of two partially sympatric taxa of Petunia Juss that hybridize in the wild despite having strong differences in pollination syndrome, mating system and environmental requirements. We evaluated 58 individuals from seven allopatric and two contact zones of Petunia axillaris and P. exserta with genomic data to study the population genetic structure and gene exchange between these species and scan for potential loci under natural selection related to the preservation of species barriers. We explicitly evaluated the time, intensity and direction of interspecific migration, testing for alternative demographic scenarios. The genetic structure showed well-differentiated species-level lineages, and poor differentiation among populations of P. axillaris; P. exserta populations were highly structured, with several well-differentiated intraspecific lineages. Our data provide evidence for admixture with low asymmetric gene flow from P. axillaris to P. exserta associated with recent secondary contact, suggesting that pollinator specificity is not the only trait responsible for species integrity in this system. Combining the results from FST outlier and genotype–phenotype association methods, we identified 54 non-synonymous candidate variants under natural selection. Those variants are found in 35 coding sequences from which we found genes related to light-response networks, supporting that extrinsic factors such as habitat preferences can also provide a mechanism of reproductive isolation between Petunia spp. We argue that a set of pre- and post-zygotic barriers in conjunction with demographic processes maintain the species integrity.

Benzaldehyde, the simplest aromatic aldehyde, is one of the most wide-spread volatiles that serves as a pollinator attractant, flavor, and antifungal compound. However, the enzyme responsible for its formation in plants remains unknown. Using a combination of in vivo stable isotope labeling, classical biochemical, proteomics and genetic approaches, we show that in petunia benzaldehyde is synthesized via the β-oxidative pathway in peroxisomes by a heterodimeric enzyme consisting of α and β subunits, which belong to the NAD(P)-binding Rossmann-fold superfamily. Both subunits are alone catalytically inactive but, when mixed in equal amounts, form an active enzyme, which exhibits strict substrate specificity towards benzoyl-CoA and uses NADPH as a cofactor. Alpha subunits can form functional heterodimers with phylogenetically distant β subunits, but not all β subunits partner with α subunits, at least in Arabidopsis. Analysis of spatial, developmental and rhythmic expression of genes encoding α and β subunits revealed that expression of the gene for the α subunit likely plays a key role in regulating benzaldehyde biosynthesis.

Background Anthocyanins are major pigments contributing to flower coloration and as such knowledge of molecular architecture underlying the anthocyanin biosynthetic pathway (ABP) is key to understanding flower color diversification. To identify ABP structural genes and associated regulatory networks, we sequenced 16 transcriptomes generated from 10 species of Ruellia and then conducted co-expression analyses among resulting data. Results Complete coding sequences for 12 candidate structural loci representing eight genes plus nine candidate regulatory loci were assembled. Analysis of non-synonymous/synonymous (dn/ds) mutation rates indicated all identified loci are under purifying selection, suggesting overall selection to prevent the accumulation of deleterious mutations. Additionally, upstream enzymes have lower rates of molecular evolution compared to downstream enzymes. However, site-specific tests of selection yielded evidence for positive selection at several sites, including four in F3'H2 and five in DFR3, and these sites are located in protein binding regions. A species-level phylogenetic tree constructed using a newly implemented hybrid transcriptome–RADseq approach implicates several flower color transitions among the 10 species. We found evidence of both regulatory and structural mutations to F3′5'H in helping to explain the evolution of red flowers from purple-flowered ancestors. Conclusions Sequence comparisons and co-expression analyses of ABP loci revealed that mutations in regulatory loci are likely to play a greater role in flower color transitions in Ruellia compared to mutations in underlying structural genes.

The plant cuticle is the final barrier for volatile organic compounds (VOCs) to cross for release to the atmosphere, yet its role in the emission process is poorly understood. Here, using a combination of reverse-genetic and chemical approaches, we demonstrate that the cuticle imposes substantial resistance to VOC mass transfer, acting as a sink/concentrator for VOCs and hence protecting cells from the potentially toxic internal accumulation of these hydrophobic compounds. Reduction in cuticle thickness has differential effects on individual VOCs depending on their volatility, and leads to their internal cellular redistribution, a shift in mass transfer resistance sources and altered VOC synthesis. These results reveal that the cuticle is not simply a passive diffusion barrier for VOCs to cross, but plays the aforementioned complex roles in the emission process as an integral member of the overall VOC network.

We obtained a complete mutant line of Petunia having mutations in both F3H genes via Cas9-ribonucleoproteins delivery, which exhibited a pale purplish pink flower color. The CRISPR-Cas system is now revolutionizing agriculture by allowing researchers to generate various desired mutations in plants at will. In particular, DNA-free genome editing via Cas9-ribonucleoproteins (RNPs) delivery has many advantages in plants; it does not require codon optimization or specific promoters for expression in plant cells; furthermore, it can bypass GMO regulations in some countries. Here, we have performed site-specific mutagenesis in Petunia to engineer flower color modifications. We determined that the commercial Petunia cultivar ‘Madness Midnight’ has two F3H coding genes and designed one guide RNA that targets both F3H genes at once. Among 67 T0 plants regenerated from Cas9-RNP transfected protoplasts, we obtained seven mutant lines that contain mutations in either F3HA or F3HB gene and one complete mutant line having mutations in both F3H genes without any selectable markers. It is noteworthy that only the f3ha f3hb exhibited a clearly modified, pale purplish pink flower color (RHS 69D), whereas the others, including the single copy gene knock-out plants, displayed purple violet (RHS 93A) flowers similar to the wild-type Petunia. To the best of our knowledge, we demonstrated a precedent of ornamental crop engineering by DNA-free CRISPR method for the first time, which will greatly accelerate a transition from a laboratory to a farmer’s field.

Strigolactones are plant hormones and rhizosphere signaling molecules with key roles in plant development, mycorrhizal fungal symbioses, and plant parasitism. Currently, sensitive, specific, and high-throughput methods of detecting strigolactones are limited. Here, we developed genetically encoded fluorescent strigolactone biosensors based on the strigolactone receptors DAD2 from Petunia hybrida, and HTL7 from Striga hermonthica. The biosensors were constructed via domain insertion of circularly permuted GFP. The biosensors exhibited loss of cpGFP fluorescence in vitro upon treatment with the strigolactones 5-deoxystrigol and orobanchol, or the strigolactone analogue rac-GR24, and the ShHTL7 biosensor also responded to a specific antagonist. To overcome biosensor sensitivity to changes in expression level and protein degradation, an additional strigolactone-insensitive fluorophore, LSSmOrange, was included as an internal normalization control. Other plant hormones and karrikins resulted in no fluorescence change, demonstrating that the biosensors report on compounds that specifically bind the SL receptors. The DAD2 biosensor likewise responded to strigolactones in an in vivo protoplast system, and retained strigolactone hydrolysis activity. These biosensors have applications in high-throughput screening for agrochemical compounds, and may also have utility in understanding strigolactone mediated signaling in plants.

In 2017, various orange coloured petunia on the market turned out to be genetically modified (GM) without an official authorization for commercialization. Sequence analysis suggested these undeclared plants most probably originated from a plant transformation experiment performed in the 1980s. For a deeper understanding how GM petunia entered classical breeding programmes worldwide, and whether they originated from a single source or not, we undertook a molecular genetic characterization of the T-DNA integration sites in different GM petunia cultivars and breeding lines. By means of genome walking, we isolated different T-DNA sequences, which are located at the junctions between the T-DNA(s) and the petunia DNA. Based on the results obtained we conclude that there are at least two T-DNA copies of different lengths. This is supported by Southern blot analysis. For T-DNA1, the 3′-junction sequence was isolated, whereas the 5′-junction remained unclear. In contrast, for T-DNA2, the 5′-junction sequence was isolated, whereas the sequence isolated from the 3′-region consists only of T-DNA, but did not include the junction from the T-DNA to the petunia DNA. We developed primers for event-specific PCRs and screened a set of three orange GM petunia cultivars and 126 GM offspring from a commercial breeding program. We show that both T-DNA copies are present in all our tested GM petunia samples, which underpins the assumption of a single transgenic origin of the undeclared GM petunia. Most likely, the two T-DNAs are integrated in close proximity into the petunia genome. Electronic supplementary material The online version of this article (10.1007/s11240-020-01871-w) contains supplementary material, which is available to authorized users., Key message The recently escaped genetically modified orange petunia contain at least two T-DNAs, which have the same integration sites in all tested plant samples, indicating a single transgenic origin. Both T-DNAs can be unambiguously identified via event-specific PCRs. Electronic supplementary material The online version of this article (10.1007/s11240-020-01871-w) contains supplementary material, which is available to authorized users.

Cymbidium faberi Rolfe (Orchidaceae) is an herbaceous plant native to China, where it has a long history of cultivation owing to its beautiful flower pattern and floral fragrance. Previously, we conducted a transcriptome analysis of the flower and vegetative buds to elucidate the mechanisms of flower development in C. faberi. In the present study, we found nine secondary metabolic pathways through the KEGG pathway database that were related to the biosynthesis of methyl jasmonate (MeJA) and other volatile organic compounds. qRT-PCR was performed to analyze the expression levels of four key genes in the MeJA pathway. Among these, CfJMT (jasmonic acid carboxyl methyltransferase) had higher transcript levels in sepals, petals and labella than in other tissues. CfJMT was cloned from the petals of full-bloom flowers of C. faberi. The predicted CfJMT protein sequence contains conserved jasmonic acid methyl transferase-7 domains, indicating that it belongs to the SABATH protein family. The CfJMT coding sequence driven by the CaMV35S promoter was successfully transformed into Petunia hybrida through an Agrobacterium-mediated method. Although MeJA could not be detected in either wild-type or transgenic petunia plants, the leaves of the transgenic plants were smaller than those of wild-type plants and pollen development was abnormal. These results indicate that heterologous expression of CfJMT may change the levels of endogenous jasmonic acid and other hormones, but that the content of MeJA is not increased significantly by transformation with CfJMT alone. Thus, other related genes and regulation factors may play important roles in this process.

In plants, phenylalanine biosynthesis occurs via two compartmentally separated pathways. Overexpression of petunia chorismate mutase 2 (PhCM2), which catalyzes the committed step of the cytosolic pathway, increased flux in cytosolic phenylalanine biosynthesis, but paradoxically decreased the overall levels of phenylalanine and phenylalanine-derived volatiles. Concomitantly, the levels of auxins, including indole-3-acetic acid and its precursor indole-3-pyruvic acid, were elevated. Biochemical and genetic analyses revealed the existence of metabolic crosstalk between the cytosolic phenylalanine biosynthesis and tryptophan-dependent auxin biosynthesis mediated by an aminotransferase that uses a cytosolic phenylalanine biosynthetic pathway intermediate, phenylpyruvate, as an amino acceptor for auxin formation. In plants, the cytosolic phenylalanine biosynthetic intermediate phenylpyruvate can serve as an amino acceptor in tryptophan-dependent auxin biosynthesis, thus facilitating crosstalk between these two distinct primary metabolic pathways.

Wastewater generated from industries contains numerous contaminants, among which heavy metals (HMs) are non-degradable. This research work highlights the use of commonly used ornamental plants, Nicotiana alata L. and Petunia hydrida L., with compost (C) and peat moss (M), and rhizospheric bacterial augmentation using Pseudomonas japonica, for the phytostabilization of HMs from synthetic wastewater. After plant–soil acclimatization, plants were exposed for 6 weeks to synthetic wastewater, containing cadmium, chromium, copper, lead, nickel, and zinc concentrations (based on the HMs level of wastewaters collected from textile and pharmaceutical industry). Physiological response, biochemical status, and enzymatic fluctuations of plants and the distribution of HMs in plant parts and soil, were quantified. With the combined use (5% each v/v conditioner/soil) of C and M, in bio-augmented soil, physiological response and enzymatic status of both plants improved, with decreased stress injury due to HMs. Further, the plant HMs uptake was reduced, with better stabilization of HM in soil. For better phytostabilization of HMs in wastewater, the use of compost, peat moss, and bacterial augmentation is recommended with Nicotiana alata L. and Petunia hydrida L.

Background and objective Flavonols in plants are catalyzed by flavonol synthase (FLS) enzyme. FLS was reported expressed in flowers and fruits, i.e., Dianthus caryophyllus L. (Caryophyllaceae), Petunia hybrida Hort. (Solanaceae), Arabidopsis thaliana L. (Brassicaceae), Citrus unshiu Marc. (Rutaceae). However, none reported about FLS in medicinal plants, particularly those which possess anti-inflammatory activity. This study was aimed to extract and identify FLS in the rhizome of Boesenbergia rotunda (Zingiberaceae) and to determine quercetin in the ethanol extract of the rhizome. Materials and methods The protein extraction of the rhizome was carried out by employing Laing and Christeller's (2004) and Wang's (2014) methods. The extracted-proteins were separated by using SDS-PAGE, followed by the measurement of FLS intensity by using Gel Analyzer. The FLS-1 of recombinant A. thaliana was employed as the standard. The determination of quercetin in the rhizome was carried out using LC-MS. Results The FLS occurred as a thick band at 38 kDa with intensity 116-158. The LC chromatogram of the extract indicated a small peak at 7.94 min similar to that of quercetin standard. The MS spectra at 7.94 min indicated that quercetin is present in the B. rotunda rhizome (m/z = 303.0549). The concentration of quercetin in the extract is 0.022% w/v. Conclusion The FLS, an enzyme which plays an important role in producing quercetin, was detected in B. rotunda rhizome planted in Indonesia. As a consequence, quercetin in a small amount, was also quantified in the rhizome of this plant. This report will add a scientific insight of B. rotunda for biological sciences.

Theobjective of this study was to investigate the effects of different growingmedia on plant growth and nutrient contents of petunia (Petunia hybrida). The experiment was conducted in a chamber roomunder controlled conditions at the laboratory. Seven different media (soil, 3:1soil: peat (P1), 2:1 soil: peat (P2), 3:1 soil: barnyard manure (BYM1), 2:1soil: barnyard manure (BYM2), 3:1 soil: sugar beet pulp (SBP1), 2:1 soil: sugarbeet pulp (SBP2)) were used as plant growing media. The experiment was endedafter three months following transplanting of seedlings. Plant growth andflower parameters and macro-micro nutrient contents were determined inharvested plants. The highest stem diameter, branch number, flower diameter,flower stalk diameter, plant fresh weight and plant dry weight were in 2:1ratio of soil: peat mixture as 7.00 mm, 6.33, 8.91 cm, 3.59 mm, 48.47 g and4.52 g while the highest plant lenght, lateral branch number and flower numbermeans were found as 27.43 cm, 24.67 and 24.67 in ratio of 3:1 soil: peatgrowing media respectively. The highest potassium, magnesium and zinc means ofplants were obtained as 6.6%, 2.2% and 32.50 mg kg-1 in soil:barnyard manure (2:1) growing media while the highest phosphorus and calciummeans of plants were found as 0.27% and 4.5% in soil and peat growing mediarespectively. The highest iron and copper means of plants were determined as231 mg kg-1 and 32.50 mg kg-1 in ratios of 2:1 and 3:1 ofsoil: sugarbeet pulp growing media respectively., The objective of this study was to investigate the effects of different growing media on plant growth and nutrient contents of petunia (Petunia hybrida). The experiment was conducted in a chamber room under controlled conditions at the laboratory. Seven different media (soil, 3:1 soil: peat (P1), 2:1 soil: peat (P2), 3:1 soil: barnyard manure (BYM1), 2:1 soil: barnyard manure (BYM2), 3:1 soil: sugar beet pulp (SBP1), 2:1 soil: sugar beet pulp (SBP2)) were used as plant growing media. The experiment was ended after three months following transplanting of seedlings. Plant growth and flower parameters and macro-micro nutrient contents were determined in harvested plants. The highest stem diameter, branch number, flower diameter, flower stalk diameter, plant fresh weight and plant dry weight were in 2:1 ratio of soil: peat mixture as 7.00 mm, 6.33, 8.91 cm, 3.59 mm, 48.47 g and 4.52 g while the highest plant lenght, lateral branch number and flower number means were found as 27.43 cm, 24.67 and 24.67 in ratio of 3:1 soil: peat growing media respectively. The highest potassium, magnesium and zinc means of plants were obtained as 6.6%, 2.2% and 32.50 mg kg-1 in soil: barnyard manure (2:1) growing media while the highest phosphorus and calcium means of plants were found as 0.27% and 4.5% in soil and peat growing media respectively. The highest iron and copper means of plants were determined as 231 mg kg-1 and 32.50 mg kg-1 in ratios of 2:1 and 3:1 of soil: sugarbeet pulp growing media respectively.

Salinity stress is one of the most important rising problems worldwide. It significantly reduces plant growth and development, mainly by provoking excessive uptake of ions such as NaIn this study, SOS3 cDNA isolated from Arabidopsis seedlings was transferred into the Petunia genome by two common plant transformation methods, Agrobacterium and biolistic gun. Transgene integration and expression in putative lines were evaluated by PCR and RT-PCR techniques. In vitro and greenhouse evaluation of transgenic plants for salt tolerance showed that, compared to the wild type, transgenic plants overexpressing AtSOS3 gene exhibit enhanced salt tolerance in response to high NaCl concentrations.These results not only demonstrate the potential of SOS pathway components to improve salt tolerance in Petunia, but also provide more evidence for functional conservation of the SOS salt tolerance signaling pathway among different plant families.

Volatile benzenoids/phenylpropanoids are the main flower scent compounds in petunia (

Plant cuticles are a mixture of crystalline and amorphous waxes that restrict the exchange of molecules between the plant and the atmosphere. The multicomponent nature of cuticular waxes complicates the study of the relationship between the physical and transport properties. Here, a model cuticle based on the epicuticular waxes of Petunia hybrida flower petals was formulated to test the effect of wax composition on diffusion of water and volatile organic compounds (VOCs). The model cuticle was composed of an n-tetracosane (C

Thai Agricultural Research Journal, 40, 2, 177-187

The popular ornamental plant Petunia is also a valuable model plant in tissue culture. Cellular conversions during differentiation and regeneration have been investigated using various combinations of phytohormones; however, studies on genes for reprogramming toward desired tissue identities have been limited. In this study, we isolated Petunia protoplasts and cultured them in the callus, rooting, or shooting stages, which were used to establish the optimal protoplast culture conditions and to identify genes that epigenetically function as tissue identifiers. The optimal conditions for plasmolysis and enzyme digestion to obtain healthy protoplasts were compared, in which combinations of Viscozyme, Celluclast, and Pectinex (VCP) enzymes were more efficient in isolating protoplasts when followed by 21 to 25% sucrose purification and washing processes. The filtered and washed protoplasts started to divide at 1 day and developed into colonies after 3 weeks of culture, which showed higher efficiency in the Murashige and Skoog (MS) salt culture media compared to that in the Kao and Michayluk (KM) salt media. The pluripotent colonies formed calli on the solid medium supplemented with 3% sucrose after 4 weeks, and were destined to the same cell mass, rooting, or shooting on the regeneration medium. Three epigenetic controllers, ATXR2, ATX4A, and ATX4B, were highly expressed in calli, shoots, and organs of shoots and roots, respectively, confirming that dedifferentiation and regeneration of tissue identity is plastic.

Details of the foraging patterns of solitary bees are much less well known than those of social species, and these patterns are often adjusted to exploit floral resources of one or only a few species. The specialized flower-visiting bees of Petunia are good models for investigating such foraging patterns. Here we analysed the floral biology and pollen presentation schedule of the endangered Petunia mantiqueirensis in mixed Araucaria forests of Serra da Mantiqueira, Brazil. Pollinators and their pollen foraging behaviour and food specialization were determined through analyses of scopa pollen loads. Flowers opened throughout the day and presented all their pollen resources within the first 30 min of anthesis, thus providing their pollen resources in an asynchronous fashion in one-flower packages throughout the day. Females of Pseudagapostemon fluminensis were the most frequent flower visitors, contacting stigmas in 96% of their visits, and were the unique effective pollinators of Petunia mantiqueirensis. These pollinators were responsible for the first three visits to 115 individually monitored flowers at any daylight hour, removing ~86% of a flower’s total pollen supply during the first visit. Although female bees harvest the majority of pollen resources of Petunia mantiqueirensis, analyses of scopa loads revealed that most of them also collect pollen from plants of other families while foraging for pollen in Petunia flowers.