Microarray-based analysis of stress-regulated microRNAs in Arabidopsis thaliana

Abstract

High-salinity, drought, and low temperature are three common environmental stress factors that seriously influence plant growth and development worldwide. Recently, microRNAs (miRNAs) have emerged as a class of gene expression regulators that have also been linked to stress responses. However, the relationship between miRNA expression and stress responses is just beginning to be explored. Here, we identified 14 stress-inducible miRNAs using microarray data in which the effects of three abiotic stresses were surveyed in Arabidopsis thaliana. Among them, 10 high-salinity-, four drought-, and 10 cold-regulated miRNAs were detected, respectively. miR168, miR171, and miR396 responded to all of the stresses. Expression profiling by RT-PCR analysis showed great cross-talk among the high-salinity, drought, and cold stress signaling pathways. The existence of stress-related elements in miRNA promoter regions provided further evidence supporting our results. These findings extend the current view about miRNA as ubiquitous regulators under stress conditions.

FIGURE 1.

Venn diagram illustrates common and unique differential miRNAs expression under three treatment conditions.

FIGURE 2.

RT-PCR validation of the microarray. (RT-PCR) results from RT-PCR analysis; (Array) results from microarray; (Man) mannitol treatment; (lane 1) 300 mM NaCl treatment; (lane 2) 200 mM mannitol treatment; (lane 3) 4°C treatment; (↑) up-regulated compared to WT; and (—) no significant difference.

FIGURE 3.

Time course of altered expression of selected miRNAs by RT-PCR analysis. PCR amplification cycles: ef1-α, 25 cycles; miRNA precursor, 33 cycles.