Identification and characterisation of maize microRNAs involved in developing ears

Area of Science:

• Plant Biology
• Genetics
• Molecular Biology

Background:

• Kernel row number in maize is a key developmental trait.
• This trait is established during the transition from spikelet pair meristems (SPMs) to spikelet meristems (SMs).
• Gene expression regulation, including post-transcriptional control by microRNAs (miRNAs), is critical during this developmental stage.

Purpose of the Study:

• To identify microRNAs (miRNAs) involved in maize ear development.
• To investigate the role of miRNAs in regulating gene expression during the formation of spikelet meristems (SMs).
• To characterize conserved and novel miRNAs in the developing maize ear.

Main Methods:

• Solexa deep sequencing was employed to profile small RNAs from maize ears.
• RNA was extracted from maize (Zong3 inbred line) ears at the specific developmental stage where SPMs transition to SMs.
• Bioinformatic analysis was used to identify and categorize conserved and novel miRNAs.

Main Results:

• Deep sequencing identified 85 conserved miRNAs from 17 different miRNA families.
• Abundance of miRNA families varied significantly, ranging from over 160,000 to as few as five reads.
• 31 novel maize miRNAs were discovered using strict identification criteria.
• Evidence suggests miRNA-mediated gene regulation occurs during maize ear development at the SPM to SM transition.

Conclusions:

• MicroRNA-mediated gene regulation plays a significant role in maize ear development.
• Both conserved and newly identified miRNAs are implicated in the developmental processes leading to kernel row determination.
• This research provides insights into the molecular mechanisms governing maize ear morphology.