Related Experiment Video
Updated: Apr 10, 2026
Generating Homo- and Heterografts Between Watermelon and Bottle Gourd for the Study of Cold-responsive MicroRNAs
Published on: November 20, 2018
Identification and characterization of cucumber microRNAs in response to Pseudoperonospora cubensis infection
1College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China.
Abstract:
MicroRNAs (miRNAs) regulate the expression of genes related to several stress responses, including fungal infection, in plants. However, the miRNA-mediated gene regulatory networks in cucumbers that respond to Pseudoperonospora cubensis stress remain unexplored. In this study, the miRNA expression patterns in response to P. cubensis stress in cucumbers were investigated through high-throughput sequencing. A total of 123 known miRNAs and 4 novel miRNAs were identified, and their corresponding expressions were detected in mock- and P. cubensis-inoculated leaves. Three novel and 39 known miRNAs were found to be differentially expressed in P. cubensis-infected leaves. The results of 5'-RLM-RACE confirmed that miR164b, miR156h, miR171e, miR160b, and miR159f targeted No Apical Meristem domain protein, squamosa promoter binding protein-like class transcription factor, GRAS family transcription factor, Auxin response factor ARF16, and a conserved gene of unknown function, respectively. The expression patterns of these miRNAs were also determined through quantitative reverse transcription polymerase chain reaction (qRT-PCR). All of these miRNAs, except for miR156h, can respond to P. cubensis infection in cucumber leaves. In addition, the results of qRT-PCR revealed that the targets negatively correlated with their corresponding miRNAs (miR164b, miR171e, miR160b, and miR159f).
Insights
This study reveals key microRNAs (miRNAs) involved in cucumber
Area of Science:
- Plant molecular biology and genetics
- Plant-pathogen interactions
- Biotechnology and agricultural science
Background:
- MicroRNAs (miRNAs) are crucial regulators of plant stress responses, including fungal infections.
- The specific miRNA regulatory networks in cucumbers responding to *Pseudoperonospora cubensis* (downy mildew) remain largely uncharacterized.
Purpose of the Study:
- To investigate and characterize the miRNA expression patterns and regulatory networks in cucumber plants under *Pseudoperonospora cubensis* stress.
- To identify novel and known miRNAs differentially expressed during infection and their potential target genes.
Main Methods:
- High-throughput sequencing was employed to profile miRNA expression in cucumber leaves after mock and *P. cubensis* inoculation.
- 5'-RLM-RACE (Rapid Amplification of cDNA Ends) was used to validate miRNA-target interactions.
- Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to confirm miRNA expression levels and their correlation with target gene expression.
Main Results:
- A total of 123 known and 4 novel miRNAs were identified. 3 novel and 39 known miRNAs showed differential expression upon *P. cubensis* infection.
- Specific miRNAs (miR164b, miR156h, miR171e, miR160b, miR159f) were confirmed to target key regulatory proteins, including transcription factors.
- Most identified miRNAs, except miR156h, responded to *P. cubensis* infection, with their targets showing negative correlation in expression, indicating regulatory roles.
Conclusions:
- This study elucidates a significant portion of the miRNA-mediated gene regulatory network in cucumber's response to *Pseudoperonospora cubensis*.
- The identified differentially expressed miRNAs and their validated targets provide valuable insights into the molecular mechanisms underlying cucumber downy mildew resistance.
- These findings lay the groundwork for developing miRNA-based strategies to enhance cucumber's resilience against fungal pathogens.
