Significant circRNAs, microRNAs, and Target Genes Participate in the Rooting Process of Acer truncatum.

Area of Science:

• Plant Molecular Biology
• Genomics
• Biotechnology

Background:

• Acer truncatum is a valuable tree species, but its rooting is challenging.
• Adventitious root formation in stem cuttings often requires plant growth hormones like Indole-3-butyric acid (IBA).
• Understanding the molecular mechanisms regulating rooting is crucial for improving propagation.

Purpose of the Study:

• To elucidate the regulatory roles of non-coding RNAs (ncRNAs) and messenger RNAs (mRNAs) in Acer truncatum rooting.
• To investigate the competitive endogenous RNA (ceRNA) interactions governing adventitious root development.
• To identify key molecular players in the rooting process of Acer truncatum.

Main Methods:

• Whole transcriptome analysis of control and IBA-treated Acer truncatum stem cuttings.
• Identification and analysis of differentially expressed mRNAs, miRNAs, lncRNAs, and circRNAs.
• Validation of regulatory networks using real-time quantitative PCR, dual luciferase assays, and GUS staining.
• Functional analysis via overexpression and bimolecular fluorescence complementation (BiFC) and yeast two-hybrid (Y2H) assays.

Main Results:

• 133 differentially expressed mRNAs, 58 miRNAs, 81 lncRNAs, and 3 circRNAs were identified.
• A regulatory network involving ciRNA46, miR164b, and NAC1 was identified and validated.
• NAC1 was found to promote adventitious root development, while miR164b inhibited it.
• NAC1 interacts with SHORT-ROOT, suggesting a broader role in root development.

Conclusions:

• The ciRNA46-miR164b-NAC1 pathway is a critical regulator of adventitious rooting in Acer truncatum.
• ncRNA-mRNA interactions, particularly ceRNA mechanisms, are fundamental to rooting.
• This study provides a molecular basis for enhancing Acer truncatum propagation and understanding plant rooting mechanisms.