Rosa roxburghii tratt (R. roxburghii) is an important plant resource that is widely distributed in the southwest of China and favored by consumers due to its high nutritional value and healthy functions. Meanwhile, it is a traditional edible and medicinal plant in China. With the deepening research of R. roxburghii, more and more bioactive components and its health care and medicinal value have been discovered and developed in recent years. This review summarizes and discusses the recent advances on main active ingredients such as vitamin, protein, amino acid, superoxide dismutase, polysaccharide, polyphenol, flavonoid, triterpenoid and mineral, and pharmacological activities including antioxidant activity, immunomodulatory activity, anti-tumor activity, glucose and lipid metabolism regulation, anti-radiation effect, detoxification effect, and viscera protection of R. roxbughii, as well as its development and utilization. The research status and existing problems of R. roxburghii development and quality control are also briefly introduced. This review ends with some suggestions on the perspectives and directions for future research and potential applications of R. roxbughii.

Rosa roxburghii Tratt. is a specific fruit with high nutritional value and antioxidative activities. However, the key metabolites and their biosynthesis are still unknown. Herein, a main cultivated variety, ‘Guinong 5’ (Rr5), was chosen to analyze the metabolomics of the three developmental stages of R. roxburghii fruit by liquid chromatography–tandem mass spectrometry (LC-MS/MS). A total of 533 metabolites were identified, of which 339 were significantly altered. Total phenols, flavonoids, and amino acids were significantly correlated to at least one in vitro antioxidant activity. The conjoint Kyoto Encyclopedia of Genes and Genomes (KEGG) co-enrichment analysis of metabolome and transcriptome was focused on amino acid, phenylpropanoid, and flavonoid biosynthesis pathways. The amino acid, phenolic acid, and flavonol biosynthesis networks were constructed with 32 structural genes, 48 RrMYBs, and 23 metabolites. Of these, six RrMYBs correlated to 9–15 metabolites in the network were selected to detect the gene expression in six different R. roxburghii genotypes fruits. Subsequently, 21 key metabolites were identified in the in vitro antioxidant activities in the fruits at various developmental stages or in fruits of different R. roxburghii genotypes. We found that four key RrMYBs were related to the significantly varied amino acids, phenolic acids, and flavonol derivatives in the network during fruit development and the key metabolites in the in vitro antioxidative activities in the fruits of six R. roxburghii genotypes. This finding provided novel insights into the flavonoid, polyphenol, and amino acid synthesis in R. roxburghii.

The fruits of Rosa roxburghii (R. roxburghii) Tratt., which are rich in bioactive compounds, provide numerous health benefits, yet the overall metabolism of R. roxburghii fruits and the metabolic profiles among different genotypes of R. roxburghii fruits are not fully understood. In the research, we used ultra-performance liquid chromatography/tandem mass spectrometry analysis to identify and quantify metabolites including phenolic acids, amino acids, and organic acids in six R. roxburghii genotypes; a total of 723 metabolites were identified. Comparative analysis showed some different characteristic metabolites in each genotype. Moreover, flavonoids, triterpenoids, and phenolic acids were significantly correlated with the antioxidant capacity of the fruit extract. Our results suggest that R. roxburghii fruits have rich bioactive metabolites beneficial to human health and that Rr-7 and Rr-f have more potential to be used as medicinal material or functional food than other genotypes. This research provides helpful information for developing new functional foods of R. roxburghii genotypes.

Top rot is a new fungal fruit disease in Rosa roxburghii production regions of southwest China. In this study, the pathogen of top rot disease in R. roxburghii fruits was firstly identified as Colletotrichum fructicola CXCDF-3 based on the pathogenicity, morphology, and multigene phylogenetic analysis. The biological property test results indicated that the optimal growth conditions of C. fructicola CXCDF-3 were 25 °C, pH 6.0~8.0, full light or darkness, D-(+) maltose, peptone, and PDA medium. Moreover, difenoconazole, tebuconazole, azoxystrobin, prothioconazole, thiophanate-methyl, prochloraz, carbendazim, and cyprodinil displayed superior toxicity activities to C. fructicola CXCDF-3 with EC₅₀ values of 0.26, 0.64, 0.99, 2.15, 4.64, 4.89, 7.27, and 7.73 mg L⁻¹, respectively. The field control efficacies of 80% tebuconazole water-dispersible granule (WG) 6000-fold liquid, 10% difenoconazole WG 5000-fold liquid, and 250 g/L azoxystrobin emulsifiable concentrate (SC) 1000-fold liquid against top rot disease of R. roxburghii fruits were 85.44%, 84.47%, and 83.50%, respectively. This study reports for the first time that the novel top rot disease in R. roxburghii is caused by C. fructicola and highlights that 80% tebuconazole WG, 10% difenoconazole WG, and 250 g/L azoxystrobin SC could be recommended for controlling top rot disease.

Autophagy is a highly conserved process in eukaryotes that degrades and recycles damaged cells in plants and is involved in plant growth, development, senescence, and resistance to external stress. Top-rot disease (TRD) in Rosa roxburghii fruits caused by Colletotrichum fructicola often leads to huge yield losses. However, little information is available about the autophagy underlying the defense response to TRD. Here, we identified a total of 40 R. roxburghii autophagy-related genes (RrATGs), which were highly homologous to Arabidopsis thaliana ATGs. Transcriptomic data show that RrATGs were involved in the development and ripening processes of R. roxburghii fruits. Gene expression patterns in fruits with different degrees of TRD occurrence suggest that several members of the RrATGs family responded to TRD, of which RrATG18e was significantly up-regulated at the initial infection stage of C. fructicola. Furthermore, exogenous calcium (Ca²⁺) significantly promoted the mRNA accumulation of RrATG18e and fruit resistance to TRD, suggesting that this gene might be involved in the calcium-mediated TRD defense response. This study provided a better understanding of R. roxburghii autophagy-related genes and their potential roles in disease resistance.