Reprogramming of Root Cells during Nitrogen-Fixing Symbiosis Involves Dynamic Polysome Association of Coding and...

Area of Science:

• Plant-microbe interactions
• Molecular biology
• Genetics

Background:

• Translational control is crucial for rapid gene expression modulation in eukaryotes.
• Nitrogen-fixing symbiosis involves complex molecular crosstalk between plants and bacteria.
• Understanding gene regulation during symbiosis is key to improving crop yields.

Purpose of the Study:

• To characterize translational regulation of mRNAs during early nitrogen-fixing symbiosis in Medicago truncatula.
• To identify key regulatory RNAs and proteins involved in this process.
• To elucidate the roles of translational control and mRNA decay in symbiosis establishment.

Main Methods:

• Translating ribosome affinity purification (TRAP) coupled with RNA sequencing.
• Analysis of protein-coding and long noncoding RNA (lncRNA) regulation.
• Functional analysis including gene knockdown experiments.

Main Results:

• Poor correlation observed between transcriptional and translational changes.
• Hundreds of protein-coding and lncRNAs were found to be translationally regulated.
• A short variant of lncRNA TAS3 modulated nodule formation by interacting with microRNA390.
• Upregulation of SKI3 mRNA enhanced nodule development and bacterial survival.

Conclusions:

• Translational control plays a significant role in nitrogen-fixing symbiosis.
• The lncRNA TAS3 and mRNA decay pathways are critical for successful symbiosis.
• Targeting translational regulation offers potential strategies for improving legume symbiosis.