Rosa Hybrida Research Articles

The histone deacetylase RhHDA15 represses petal senescence by epigenetically regulating reactive oxygen species homeostasis in rose

Abstract Epigenetic modifications play vital roles in many biological processes. Flower senescence involves epigenetic factors that influence the chromatin state and gene expression. However, the molecular mechanism underlying the role of histone deacetylation in regulating flower senescence has not been elucidated. Here, we demonstrate that histone deacetylation is involved in flower senescence by fine-tuning reactive oxygen species (ROS) homeostasis in rose (Rosa hybrida). Our data reveal that the histone lysine deacetyltransferase RhHDA15 inhibits ROS accumulation and petal senescence by downregulating the expression of NADPH OXIDASE/RESPIRATORY BURST OXIDASE HOMOLOG (RhRboh) genes. Furthermore, the transcription factor RELATED TO ABI3/VP1 2 (RhRAV2) recruits RhHDA15 and the co-repressor TOPLESS (RhTPL) to suppress flower senescence by reducing H3 lysine 9 acetylation (H3K9ac) at the RhRbohA1/2 promoter and thus directly inhibiting precocious RhRbohA1/2 expression. Our work sheds light on an epigenetic mechanism in which histone deacetylation plays a crucial role in controlling petal senescence by precisely fine-tuning ROS homeostasis, providing insights into the regulatory network of organ senescence.

Studies on the effect of polyamines supplementation on growth and biochemical parameters in rose micropropagation

Rose (Rosa hybrida L. cv. bush rose) micropropagules were cultivated on MS medium supplemented with polyamines (PAs) [Cadaverine (Cad), Spermidine (Spd), and Putrescine (Put)] to investigate its effects on growth and multiplication under in vitro conditions during 2023. Polyamines were added to the medium at different concentrations of 10 mM, 30 mM, and 50 mM via filter sterilization before autoclaving, to assess their impact on in vitro growth parameters, which indicate that a lower concentration of polyamines, specifically at 30 mM, significantly enhances biomass accumulation and overall plant growth, whereas higher concentrations (50 mM) tend to exert a diminishing effect. Biochemical parameters revealed that polyamines at 30 mM notably increased the levels of key biomolecules, including carbohydrates content, proteins content, and chlorophylls content, and also shows significant level of phenol content in the rose micropropagules. Furthermore, antioxidant activities, as measured by superoxide dismutase and peroxidase activities, was markedly higher in micropropagules grown on medium supplemented with 30 mM polyamines These findings suggest that low concentrations of polyamines can serve as effective growth regulators, promoting enhanced growth and biochemical responses in rose micropropagation. Therefore, incorporating polyamines, particularly at optimal concentrations, could improve the efficiency and quality of rose micropropagation protocols, benefiting commercial production and conservation efforts.

Enhanced preservation of cut rose flowers through bacterial nanocellulose produced from legume wastewater and fortified with Auricularia auricula polysaccharide

Cut flowers of Rosa hybrida 'Lychee' are susceptible to rapid decay, resulting in a brief shelf life, a inherent feature to their floral physiology. This study evaluated the effects of bacterial nanocellulose (BNC), which was produced from the legume processing wastewater and loaded with Auricularia auricula polysaccharide and 8-hydroxyquinoline, in extending the shelf life of these cut rose flowers. Water-retaining cotton and floral foam blocks were employed as control materials. The bacterial strain Komagataeibacter rhaeticus CP050139.1 yielded BNC from legume waste at a rate comparable to that from a glucose-based medium: 0.107±0.004 g L−1 d−1 versus 0.157±0.004 g L−1 d−1, respectively. Characterization via FE-SEM, FT-IR, TGA, and XRD confirmed that the BNC from both sources exhibited similar microscopic morphology, chemical composition, thermal stability, and crystallinity. The use of BNC, particularly when enriched with Auricularia auricula polysaccharide (AAP), extended the shelf life of cut roses by 50 % and significantly minimized fresh weight loss in comparison to the control materials. BNC's superior water-holding capacity — 42.7 times greater than that of water-retaining cotton — proved advantages for maintaining hydration and preventing wilting during transportation. This study underscored the potential of BNC hydrogel, sourced from legume processing wastewater, as an innovative, effective, and environmentally sustainable solution for preserving cut rose flowers, promoting the recycling of agricultural by products and enhancing the preservation of horticultural products.

Haplotype-resolved genome assembly and resequencing provide insights into the origin and breeding of modern rose.

Modern rose (Rosa hybrida) is a recently formed interspecific hybrid and has become one of the most important and widely cultivated ornamentals. Here we report the haplotype-resolved chromosome-scale genome assembly of the tetraploid R. hybrida 'Samantha' ('JACmantha') and a genome variation map of 233 Rosa accessions involving various wild species, and old and modern cultivars. Homologous chromosomes of 'Samantha' exhibit frequent homoeologous exchanges. Population genomic and genomic composition analyses reveal the contributions of wild Rosa species to modern roses and highlight that R. odorata and its derived cultivars are important contributors to modern roses, much like R. chinensis 'Old Blush'. Furthermore, selective sweeps during modern rose breeding associated with major agronomic traits, including continuous and recurrent flowering, double flower, flower senescence and disease resistance, are identified. This study provides insights into the genetic basis of modern rose origin and breeding history, and offers unprecedented genomic resources for rose improvement.

Extension of Vase Life by Nano-Selenium in Rosa hybrida

Vase life directly affects the ornamental value of cut flowers, and extending vase life has been a research focus in the floriculture industry. The antioxidant and antimicrobial properties of Nano-Se provide a new direction to extend the life of cut-flower vase life. In order to explore the postharvest quality of Nano-Se on cut-flower roses, this study treated cut-flower roses with different concentrations of Nano-Se (200, 400, and 600 mM) using a commercially available preservative solution as a base solution. The results showed that appropriate concentrations of Nano-Se significantly increased the vase life of cut-flower roses and helped to maintain high petal moisture content. Nano-Se at concentrations of 200, 400, and 600 mM extended the vase life of cut roses by 4.3, 5.7, and 3.7 d, respectively. As the vase period extended, the Nano-Se treatment group effectively delayed the decline in antioxidant enzyme activities such as peroxidase (POD) and catalase (CAT), maintained the soluble sugar (SS) and soluble protein (SP) contents in the cut roses, and inhibited the production of malondialdehyde (MDA) and hydrogen peroxide (H2O2), reducing their accumulation. A correlation analysis of the physiological indexes of cut roses showed that vase life was positively correlated with POD and CAT activities, SS and SP contents, and total phenolic acid content and negatively correlated with MDA and H2O2 contents. This study provides a solid theoretical basis for the diversification of preservatives and the development of new preservatives for fresh-cut roses, which is expected to provide significant economic benefits.

Assessment of biological activity in vitro and phytochemical constituents from Rosa hybrida leaves

Assessment of biological activity <i>in vitro</i> and phytochemical constituents from <i>Rosa hybrida</i> leaves

Multi-omics analyzes of Rosa gigantea illuminate tea scent biosynthesis and release mechanisms.

Rose is an important ornamental crop cultivated globally for perfume production. However, our understanding of the mechanisms underlying scent production and molecular breeding for fragrance is hindered by the lack of a reference genome for tea roses. We present the first complete telomere-to-telomere (T2T) genome of Rosa gigantea, with high quality (QV > 60), including detailed characterization of the structural features of repetitive regions. The expansion of genes associated with phenylpropanoid biosynthesis may account for the unique tea scent. We uncover the release rhythm of aromatic volatile organic compounds and their gene regulatory networks through comparative genomics and time-ordered gene co-expression networks. Analyzes of eugenol homologs demonstrate how plants attract pollinators using specialized phenylpropanoids in specific tissues. This study highlights the conservation and utilization of genetic diversity from wild endangered species through multi-omics approaches, providing a scientific foundation for enhancing rose fragrance via de novo domestication.

Transcriptomics and metabolomics analyses of Rosa hybrida to identify heat stress response genes and metabolite pathways

BackgroundGlobal warming has greatly increased the impact of high temperatures on crops, resulting in reduced yields and increased mortality. This phenomenon is of significant importance to the rose flower industry because high-temperature stress leads to bud dormancy or even death, reducing ornamental value and incurring economic losses. Understanding the molecular mechanisms underlying the response and resistance of roses to high-temperature stress can serve as an important reference for cultivating high-temperature-stress-resistant roses.ResultsTo evaluate the impact of high temperatures on rose plants, we measured physiological indices in rose leaves following heat stress. Protein and chlorophyll contents were significantly decreased, whereas proline and malondialdehyde (MDA) contents, and peroxidase (POD) activity were increased. Subsequently, transcriptomics and metabolomics analyses identified 4,652 common differentially expressed genes (DEGs) and 57 common differentially abundant metabolites (DAMs) in rose plants from four groups. Enrichment analysis showed that DEGs and DAMs were primarily involved in the mitogen-activated protein kinases (MAPK) signaling pathway, plant hormone signal transduction, alpha-linolenic acid metabolism, phenylpropanoid biosynthesis, and flavonoid biosynthesis. The combined analysis of the DEGs and DAMs revealed that flavonoid biosynthesis pathway-related genes, such as chalcone isomerase (CHI), shikimate O-hydroxycinnamoyl transferase (HCT), flavonol synthase (FLS), and bifunctional dihydroflavonol 4-reductase/flavanone 4-reductase (DFR), were downregulated after heat stress. Moreover, in the MAPK signaling pathway, the expression of genes related to jasmonic acid exhibited a decrease, but ethylene receptor (ETR/ERS), P-type Cu + transporter (RAN1), ethylene-insensitive protein 2/3 (EIN2), ethylene-responsive transcription factor 1 (ERF1), and basic endochitinase B (ChiB), which are associated with the ethylene pathway, were mostly upregulated. Furthermore, heterologous overexpression of the heat stress-responsive gene RcHSP70 increased resistance to heat stress in Arabidopsis thaliana.ConclusionThe results of this study indicated that the flavonoid biosynthesis pathway, MAPK signaling pathway, and plant hormones may be involved in high-temperature resistance in roses. Constitutive expression of RcHSP70 may contribute to increasing high-temperature tolerance. This study provides new insights into the genes and metabolites induced in roses in response to high temperature, and the results provide a reference for analyzing the molecular mechanisms underlying resistance to heat stress in roses.

RhLHY-RhTPPF-Tre6P Inhibits Flowering in Rosa hybrida Under Insufficient Light by Regulating Sugar Distribution.

Light is crucial for flower bud development in plants, serving as both signal and energy source. However, the mechanisms by which daylength and light intensity regulate flowering in modern roses remain unclear. In Rosa hybrida 'Carola', insufficient light delays flowering and reduces the sugar content in terminal buds. RNA sequencing identified the Trehalose-6-phosphate phosphatase F (RhTPPF) gene as a key responder to insufficient light, modulating Tre6P metabolism. Overexpression of RhTPPF in rose calli enhanced sugar accumulation and suppressed the synthesis of RhCO/FT. In tobacco, overexpression of RhTPPF delayed the transition from vegetative growth to flowering, while silencing RhTPPF in roses accelerated flowering. Silencing RhTPPF in roses elevated trehalose-6-phosphate (Tre6P) levels and decreased trehalose. Transcriptome data showed that the expression level of RhTPPF was highly correlated with the circadian rhythm gene LATE ELONGATED HYPOCOTYL (RhLHY). Yeast one-hybrid assays, dual luciferase assays and EMSA revealed that RhLHY directly binds to the RhTPPF promoters. Overexpression of RhLHY suppressed flowering, while silencing RhLHY promoted flowering. Furthermore, altering the expression of RhLHY influenced Tre6P synthesis and the expression of sucrose-related transport genes. These findings suggest a RhLHY-RhTPPF-Tre6P regulatory module that maintains sugar balance and inhibits flower formation under reduced light conditions by modulating sugar distribution.

Cytokinin-responsive RhRR1-RhSCL28 transcription factor module positively regulates petal size by promoting cell division in rose.

Petal size, a crucial trait in the economically important ornamental rose (Rosa hybrida), is synergistically regulated by cell division and cell expansion. Cell division primarily occurs during the early development of petals. However, the molecular mechanism underlying the regulation of petal size is far from clear. In this study, we isolated the transcription factor gene RhSCL28, which is highly expressed at the early stage of rose petal development and is induced by cytokinin. Silencing RhSCL28 resulted in a reduced final petal size and reduced cell number in rose petals. Further analysis showed that RhSCL28 participates in the regulation of cell division by positively regulating the expression of the cyclin genes RhCYCA1;1 and RhCYCB1;2. To explore the potential mechanism for cytokinin-mediated regulation of RhSCL28 expression, we investigated the cytokinin response factor RhRR1 and determined that it positively regulates RhSCL28 expression. Like RhSCL28, silencing RhRR1 also resulted in smaller petals by decreasing cell number. Taken together, these results reveal that the RhRR1-RhSCL28 module positively regulates petal size by promoting cell division in rose.

Genome-wide analysis of the WOX gene family and function exploration of RhWOX331 in rose (R. 'The Fairy').

WOXs are a class of plant-specific transcription factors that play key roles in plant growth and stress responses. However, the mechanism by which WOXs influence adventitious root development in Rosa hybrida remains unclear. In this study, RcWOX gene family in rose was identified and phylogenetically analyzed using bioinformatics analysis. A total of 381 RcWOX gene members were localized on seven chromosomes except of nine members. The main cis-acting elements involved in hormonal, light, developmental, and abiotic stress responses were identified in the promoters of RcWOX genes, suggesting their regulation by these signals. Nine RhWOX genes had significant different expression during rooting process of rose. RhWOX331, RhWOX308, RhWOX318 were positive with the formation of rose roots. RhWOX331 was positively involved in the formation of adventitious root primordia, which gene coding a transcription factor localized in the nucleus. The HOX conserved domain in the protein contributed to the self-activating activity of RhWOX331. We obtained genetically modified Arabidopsis to validate the function of RhWOX331. Overexpression of RhWOX331 gene alleviated the inhibition of root length of A. thaliana primary roots by high concentration of IBA and NPA, and significantly increased the number of lateral roots on the primary roots, as well as the height of A. thaliana plants. Additionally, RhWOX331 promoted adventitious root formation in A. thaliana and mitigated hormonal inhibition by exogenous 6-BA, NPA, and GA3. The RhWOX331 promoter contained cis-acting elements such as ABRE, Box 4 and CGTCA-motif et.al. GUS activity analysis showed that the gene acted at the cotyledon attachment site. Taken together, these studies identified a significant expansion of the RcWOX gene family, inferred roles of certain branch members in adventitious root formation, elucidated the function of RhWOX331 in adventitious root initiation, and laid the foundation for further research on the function of WOX gene family in roses.

Genome-Wide Identification and Analysis of the Aux/IAA Gene Family in Rosa hybrida—“The Fairy”: Evidence for the Role of RhIAA25 in Adventitious Root Development

Propagation of cuttings is the primary method of rose multiplication. Aux/IAA, early response genes to auxin, play an important role in regulating the process of adventitious root formation in plants. However, systematic research on the identification of RhAux/IAA genes and their role in adventitious root formation in roses is lacking. In this study, 34 RhAux/IAA genes were identified by screening the rose genome, distributed on seven chromosomes, and classified into three clades based on the evolutionary tree. An analysis of the cis-acting elements in the promoters of RhAux/IAA genes revealed the presence of numerous elements related to plant hormones, the light signal response, the growth and development of plants, and abiotic stress. RNA-seq analysis identified a key RhIAA25 gene that may play an important role in the generation of adventitious roots in roses. Subcellular localization, yeast self-activation, and tissue-specific expression experiments indicated that RhIAA25 encoded a nuclear protein, had no yeast self-activated activity, and was highly expressed in the stem. The overexpression of RhIAA25 promoted the elongation of the primary root in Arabidopsis but inhibited adventitious root formation. This study systematically identified and analyzed the RhAux/IAA gene family and identified a key gene, RhIAA25, that regulates adventitious root generation in roses. This study offers a valuable genetic resource for investigating the regulatory mechanism of adventitious root formation in roses.

Fabrication, properties, and morphologies of hybrid polymer composites reinforced with jute and Rosa hybrida fibers

Fabrication, properties, and morphologies of hybrid polymer composites reinforced with jute and Rosa hybrida fibers

The complexity of volatile terpene biosynthesis in roses: Particular insights into β-citronellol production.

The fascinating scent of rose (Rosa genus) flowers has captivated human senses for centuries, making them one of the most popular and widely used floral fragrances. Despite much progress over the last decade, many biochemical pathways responsible for rose scents remain unclear. We analyzed the floral scent compositions from various rose varieties and selected the modern cultivar Rosa hybrida "Double Delight" as a model system to unravel the formation of rose dominant volatile terpenes, which contribute substantially to the rose fragrance. Key genes involved in rose terpene biosynthesis were functionally characterized. Cytosolic geranyl diphosphate (GPP) generated by geranyl/farnesyl diphosphate synthase (G/FPPS1) catalysis played a pivotal role in rose scent production, and terpene synthases in roses play an important role in the formation of most volatile terpenes, but not for geraniol, citral, or β-citronellol. Subsequently, a series of enzymes, including geraniol dehydrogenase, geranial reductase, 12-oxophytodienoate reductase, and citronellal reductase, were characterized as involved in the transformation of geraniol to β-citronellol in roses through three successive steps. Interestingly, the β-citronellol biosynthesis pathway appears to be conserved in other horticultural plants like Lagerstroemia caudata and Paeonia lactiflora. Our findings provide valuable insights into the biosynthesis of rose volatile terpenoid compounds and offer essential gene resources for future breeding and molecular modification efforts.

Evaluating the Performance of Cocopeat and Volcanic Tuff in Soilless Cultivation of Roses.

Roses are increasingly being grown in soilless systems to increase productivity and reduce the challenges associated with soil-based cultivation. This study investigates the effects of using cocopeat and volcanic tuff substrates, the particle size of tuff, and substrate depth on the growth and flower quality of roses (Rosa hybrida L. cv. top secret) grown under greenhouse conditions. The treatments were cocopeat, tuff, cocopeat-tuff mixture, and tuff of particle size of 2 to 4 mm, 0 to 4 mm, and 0 to 8 mm at depths of 20 cm and 40 cm. The results showed that cocopeat had the highest water-holding capacity and photosynthetic rate. Tuff substrates had higher chlorophyll content throughout the growing season. Although flower numbers per plant in cocopeat and tuff from 0 to 8 mm at a depth of 20 cm were statistically similar, tuff from 0 to 8 mm had longer flowering stems and larger post-harvest flower diameters than cocopeat. An increase in the tuff depth from 20 to 40 cm decreased the flower number and main stem diameter. In conclusion, while cocopeat promotes rapid initial growth, volcanic tuff substrates, particularly tuff from 0 to 8 mm at a depth of 20 cm, provide long-term benefits for flower quality and plant health.

Inheritance of Some Traits in Crosses between Hybrid Tea Roses and Old Garden Roses.

The limited knowledge about the inheritance of traits in roses makes the efficient development of rose varieties challenging. In order to achieve breeding goals, the inheritance of traits needs to be explored. Additionally, for the inheritance of a trait like scent, which remains a mystery, it is crucial to know the success of parental traits in transmitting them to the next generation. Understanding this allows for accurate parental selection, ensuring sustainability in meeting market demand and providing convenience to breeders. The aim of this study was to assess the success of cross-combinations between scented old garden roses and hybrid tea roses used in cut roses in transferring their existing traits, with the objective of achieving scented cut roses. The evaluated traits included recurrent blooming, flower stem length, flower diameter, petal number, scent, and bud length of both parents and progenies. The inheritance of these traits was evaluated through theoretical evaluations, including calculating heterosis and heterobeltiosis and determining narrow-sense heritability. The combinations and examined traits were assessed using a hierarchical clustering heat map. The results of this study indicated that flower stem length, flower diameter, petal number, and bud length traits had a moderate degree of narrow-sense heritability, suggesting the influence of non-additive genes on these traits. This study observed a low success rate in obtaining progenies with scent in cross combinations between cut roses and old garden roses, indicating the challenges in obtaining scented genotypes. The discrepancy between the observed phenotypic rates and the expected phenotypic and genotypic rates, according to Punnett squares, suggests that the examined traits could be controlled by polygenic genes. The progenies were observed to exhibit a greater resemblance to old garden roses than hybrid tea roses and did not meet the commercial quality standards for cut flowers. The significant negative heterosis observed in 65.12% (petal number) and 99.61% (flower diameter) of the progenies provides strong evidence of resemblance to old garden roses. Considering these findings, it is recommended to consider old garden roses as parents, taking into account their suitability for other breeding objectives.

Improving postharvest quality and vase life of cut rose flowers by pre-harvest foliar co-applications of γ-aminobutyric acid and calcium chloride

Rose flowers (Rosa hybrida L.) are highly perishable and have a limited vase life. This study evaluated the effects of preharvest foliar applications of γ-aminobutyric acid (GABA) and calcium chloride (CaCl2), individually and combined, on antioxidant responses and vase life of cut Jumilia rose flowers. Treatments included foliar sprays of GABA at 0, 20, 40, and 60 mM and CaCl2 at 0, 0.75%, and 1.5%, applied in a factorial design within a completely randomized setup before harvest. Results showed GABA and CaCl2 interaction (especially, 60 mM GABA and 1.5% CaCl2) significantly increased enzymatic antioxidants including superoxide dismutase, catalase, and peroxidase, as well as non-enzymatic antioxidants such as flavonoids, carotenoids, phenolics, and antioxidant activity in petals compared to control. SOD activity in roses, treated with CaCl2 (1.5%) and GABA (60 mM), peaked at 7.86 units. mg−1 protein min−1, showing a nearly 2.93-fold increase over the control (2.68 units. mg−1 protein min−1). A parallel trend was observed for CAT activity. These treatments also reduced petal malondialdehyde content and polyphenol oxidase activity. Protein content and vase life duration increased in all treatments. Plants treated with a combination of GABA (20 mM) and CaCl2 (0.75%), GABA (60 mM) and CaCl2 (1.5%), or GABA (40 mM) individually exhibited the longest vase life duration. The co-application of GABA and CaCl2 improved the antioxidant activity and postharvest quality of cut roses by reducing PPO activity and MDA contents, increasing protein content and prolonging vase life. This treatment is a potential postharvest strategy to improve antioxidant capacity and delay senescence in cut roses.

Physiological and biochemical aspects of successful stenting in Rosa hybrida L.: Role of rootstock

Stenting is a commercial propagation method for roses that combines grafting and cutting in one action and the resulting plantlet is named ‘stentling’. Several physiological and biochemical factors can significantly influence graft union healing and adventitious root formation. The effect of rootstock and its cutting-prepared region have not been well studied for successful stenting. We provide a comprehensive overview of the physiological and biochemical aspects of the stenting process, utilizing rootstock positions as the source of variation among treatments. Morphophysiological and biochemical assays were performed to evaluate the effect of three different stem parts (bottom, middle, and top) of ‘Natal Briar’ as rootstock on graft union healing and adventitious root formation of the rose stentlings. When the rootstock originating from the bottom and middle positions improved the physiological, biochemical, and morphological responses of the stentling, significantly. In this regard, the improved biochemical properties, including total soluble sugars, total phenolic and flavonoid contents, phenylalanine ammonia-lyase, peroxidase and lignin content seem to play a special role in the success of grafting and subsequently the adventitious root formation. Assessing morphophysiological and biochemical parameters paves the way for a better understanding of the mechanism of successful stenting.

Flower Yield, Physiology, Nutrient Acquisition and Soil Fertility Variations in Cut Flower Rose (Rosa hybrida L.) as Influenced by Rootstocks

Flower Yield, Physiology, Nutrient Acquisition and Soil Fertility Variations in Cut Flower Rose (Rosa hybrida L.) as Influenced by Rootstocks

Comparison of Vitamin C Levels in Rose Kombucha (Rosa hybrida) during Storage

Comparison of Vitamin C Levels in Rose Kombucha (Rosa hybrida) during Storage