Studies have shown that microRNAs (miRNAs) have significant functions in
plant's response to stress brought by exposure to heavy metals. Cadmium, a
heavy metal, is one of the most deleterious pollutants in the environment.
Maize is a good candidate for investigating phytoremediation of
Cadmium-contaminated soil because of its large biomass production.
Furthermore, there is limited information about miRNAs as a response to
Cadmium stress in maize. Thus, experts from Yangtze Normal University
conducted a study to understand the function of miRNAs in response to
Cadmium stress. The results are published in BMC Molecular Biology.

The research team collected roots of seedlings of inbred maize lines B73 and
Mo17 that were subjected to Cadmium over varied exposure times. Cadmium
stress was confirmed through levels of enzymatic activities. The expression
of six candidate miRNAs and their targets were validated using quantitative
real-time PCR technology; while the expression of Zma-miR171b was evaluated
using in situ hybridization.

Results showed that miRNAs and their respective target genes were
differentially expressed in maize seedling roots exposed to Cadmium stress.
The results also provided insights into the molecular mechanism of miRNAs in
response to Cadmium stress and confirmed that miRNAs in plants play
important roles in responding to heavy metal stress.

[bmcmolbiol.biomedcentral.com]