Rose is an important economic crop in horticulture. However, its field growth and postharvest quality are negatively affected by grey mould disease caused by Botrytis c. However, it is unclear how rose plants defend themselves against this fungal pathogen. Here, we used transcriptomic, metabolomic and VIGS analyses to explore the mechanism of resistance to Botrytis c. In this study, a protein activity analysis revealed a significant increase in defence enzyme activities in infected plants. RNA-Seq of plants infected for 0 h, 36 h, 60 h and 72 h produced a total of 54 GB of clean reads. Among these reads, 3990, 5995 and 8683 differentially expressed genes (DEGs) were found in CK vs. T36, CK vs. T60 and CK vs. T72, respectively. Gene annotation and cluster analysis of the DEGs revealed a variety of defence responses to Botrytis c. infection, including resistance (R) proteins, MAPK cascade reactions, plant hormone signal transduction pathways, plant-pathogen interaction pathways, Ca2+ and disease resistance-related genes. qPCR verification showed the reliability of the transcriptome data. The PTRV2-RcTGA1-infected plant material showed improved susceptibility of rose to Botrytis c. A total of 635 metabolites were detected in all samples, which could be divided into 29 groups. Metabonomic data showed that a total of 59, 78 and 74 DEMs were obtained for T36, T60 and T72 (T36: Botrytis c. inoculated rose flowers at 36 h; T60: Botrytis c. inoculated rose flowers at 60 h; T72: Botrytis c. inoculated rose flowers at 72 h) compared to CK, respectively. A variety of secondary metabolites are related to biological disease resistance, including tannins, amino acids and derivatives, and alkaloids, among others; they were significantly increased and enriched in phenylpropanoid biosynthesis, glucosinolates and other disease resistance pathways. This study provides a theoretical basis for breeding new cultivars that are resistant to Botrytis c. Fifty-four GB of clean reads were generated through RNA-Seq. R proteins, ROS signalling, Ca2+ signalling, MAPK signalling, and SA signalling were activated in the Old Blush response to Botrytis c. RcTGA1 positively regulates rose resistance to Botrytis c. A total of 635 metabolites were detected in all samples. DEMs were enriched in phenylpropanoid biosynthesis, glucosinolates and other disease resistance pathways.

Background: Rose is one of the most popular flowers in the wold. Its field growth and quality are negatively affected by aphids. However, the defence mechanisms used by rose plants against aphids are unclear. Therefore, to understand the defence mechanism of rose under aphid stress, transcriptome and metabolome techniques were used to investigate the regulation mechanism in R. longicuspis infected with M. rosivorum. Result: In our study, after inoculation with M. rosivorum, M. rosivorum quickly colonized R. longicuspis. A total of 34,202 genes and 758 metabolites were detected in all samples. Under M. rosivorum stress, R. longicuspis responded by MAPK cascades, plant hormone signal transduction pathway activation, RlMYBs and RlERFs transcription factors expression and ROS production. Interestingly, the ‘brassinosteroid biosynthesis’ pathway was significantly enriched in A3 d-vs.-A5 d. Further analysis showed that M. rosivorum induced the biosynthesis of secondary metabolites such as terpenoids, tannins and phenolic acids, among others. Importantly, the ‘glutathione metabolic’ and ‘glucosinolate biosynthesis’ pathways were significantly enriched, which involved in the rose against aphids. Conclusion: Our study provides candidate genes and metabolites for Rosa defence against aphids. This study provides a theoretical basis for further exploring the molecular regulation mechanism of rose aphid resistance and aphid resistance breeding in the future.

The flower’s color is regarded as one of the most outstanding features of the rose. Rosa praelucens Byhouwer, an endemic and critically endangered decaploid wild rose species, is abundant in phenotypic diversity, especially in flower color variation, from white to different degrees of pink. The mechanism underlying this variation, e.g., the level of petal-color-related genes, is worth probing. Seven candidate reference genes for qRT-PCR analysis, including tubulin α chain (TUBA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone H2B (Histone2A), eukaryotic translation elongation factor 1-α (EEF1A), 60S ribosomal protein (RPL37), eukaryotic translation initiation factor 1-α (EIF1A), and aquaporins (AQP), were detected from the transcriptome datasets of full blooming flowers of white-petaled and pink-petaled individuals, and their expression stabilities were evaluated through qRT-PCR analysis. According to stability rankings analysis, EEF1A showed the highest stability and could be chosen as the most suitable reference gene. Moreover, the reliability of EEF1A was demonstrated via qRT-PCR analysis of six petal-color-related target genes, the expression patterns of which, through EEF1A normalization, were found to be consistent with the findings of transcriptome analysis. The result provides an optimal reference gene for exploring the expression level of petal-color-related genes in R. praelucens, which will accelerate the dissection of petal-color-variation mechanisms in R. praelucens.

Background: Rose is an important economic horticultural crop. However, its field growth and quality are negatively affected by aphids. However, the defence mechanisms used by rose plants against aphids are unclear. A previous study showed that Macrosiphum rosivorum is the most common and harmful aphid species to Rosa plants and that Rosa longicuspis is highly resistant species to aphids. Therefore, to understand the defence mechanism of rose under aphid stress, we combined RNA sequencing and metabolomics techniques to investigate the changes in gene expression and metabolomic processes in R. longicuspis infected with M. rosivorum. Result: In our study, after inoculation with M. rosivorum, M. rosivorum quickly colonized. A total of 34202 genes and 758 metabolites were detected in all samples, with 2845, 2627 and 466 differentially expressed genes (DEGs) were found in CK-vs.-A3 d, CK-vs.-A5 d, and A3 d-vs.-A5 d, respectively. Among these metabolites, 65, 70 and 26 differentially expressed metabolites (DEMs) were found in CK-vs.-A3 d, CK-vs.-A5 d, and A3 d-vs.-A5 d, respectively. The combined omics approach revealed that M. rosivorum is perceived by effector-triggered immunity. Under M. rosivorum stress, R. longicuspis responded by signal transduction pathway activation, transcription factor expression, ROS production and hormone-mediated defence responses. Interestingly, the ‘brassinosteroid biosynthesis’ pathway was significantly enriched in A3 d-vs.-A5 d. Further analysis showed that M. rosivorum induced the transformation of starch and sucrose, the biosynthesis of terpenoids, tannins and phenolic acids and metabolism of cyanoamino acid. Importantly, the ‘tropane, piperidine and pyridine alkaloid biosynthesis’, ‘glutathione metabolic’ and ‘glucosinolate biosynthesis’ pathways were significantly enriched, which resulted in increased levels of metabolites that were involved in the plant defence response. Conclusion: Our study provides candidate genes and metabolites for Rosa defence against aphids. What’s more, this study provides a theoretical basis for further exploring the molecular regulation mechanism of rose aphid resistance and aphid resistance breeding in the future.