Dehydration-responsive miRNAs in foxtail millet: genome-wide identification, characterization and expression...

Area of Science:

• Plant Molecular Biology
• Genomics
• Abiotic Stress Response

Background:

• MicroRNAs (miRNAs) are crucial regulators of plant growth, development, and stress responses.
• MiRNA-mediated gene regulatory networks in response to dehydration stress are underexplored in foxtail millet (Setaria italica), a naturally stress-tolerant crop.

Purpose of the Study:

• To globally identify dehydration-responsive miRNAs in foxtail millet.
• To investigate the role of miRNAs and their targets in contrasting dehydration tolerance between cultivars.
• To elucidate miRNA-mediated post-transcriptional regulation under dehydration stress.

Main Methods:

• Construction and sequencing of four small RNA libraries from control and dehydration-stressed foxtail millet seedlings (two cultivars).
• Identification of known and novel miRNAs using Illumina sequencing technology.
• Validation of miRNA expression using northern blot and SL-qRT PCR.
• Validation of miRNA-target gene expression using RLM RACE.

Main Results:

• Identification of 55 known and 136 novel miRNAs, belonging to 22 and 48 families, respectively.
• Discovery of 18 known and 33 novel differentially expressed miRNAs under dehydration stress.
• Identification of 32 up-regulated and 22 down-regulated miRNAs in tolerant and sensitive cultivars, respectively.
• Prediction of miRNA targets involved in transcription factors and functional enzymes.

Conclusions:

• A significant set of novel and known dehydration-responsive miRNAs were identified in foxtail millet.
• These findings offer new insights into the functional roles of miRNAs and their targets in plant dehydration stress response.
• The study underscores the importance of miRNA-mediated post-transcriptional regulation in a naturally stress-tolerant crop.