Exploring the drought-responsive miRNAs and their corresponding target genes in chickpea root tissue

Area of Science:

• Plant Molecular Biology
• Genomics
• Crop Science

Background:

• Chickpea (Cicer arietinum) is a vital global pulse crop facing significant yield losses due to abiotic stressors like drought.
• MicroRNAs (miRNAs), small non-coding RNAs, are crucial regulators of gene expression in response to environmental challenges.
• Understanding miRNA roles in chickpea drought tolerance is essential for developing resilient crop varieties.

Purpose of the Study:

• To investigate the role of drought-responsive microRNAs in chickpea root tissues.
• To identify and characterize conserved and novel miRNAs involved in chickpea's response to drought stress.
• To elucidate specific miRNA-target interactions regulating drought tolerance mechanisms.

Main Methods:

• Small RNA sequencing of chickpea root tissues from contrasting drought-tolerant genotypes.
• Bioinformatic analysis to identify conserved and novel miRNA sequences.
• Quantitative real-time PCR (qRT-PCR) for miRNA validation.
• 5' RNA Ligase-Mediated Rapid Amplification of cDNA Ends (5´RLM-RACE) to confirm miRNA-guided target cleavage.

Main Results:

• Identification of 224 conserved and 155 novel miRNA sequences from chickpea roots.
• The miR156 family was the most abundant among 51 conserved miRNA families.
• Validation of eleven conserved and six novel miRNAs using qRT-PCR.
• Confirmation of specific miRNA-mediated cleavage of target genes (SCL27 by miR171, ATHB15 by miR166) in drought-stressed roots.

Conclusions:

• Diverse microRNAs are significantly involved in chickpea's mitigation of drought stress.
• Specific miRNAs, such as miR171 and miR166, directly regulate key target genes impacting drought tolerance.
• This research provides insights into miRNA-mediated regulatory networks crucial for chickpea adaptation to drought.