Modification of root microRNAs expression and exudation of wheat in response to bisphenol A contamination
Résumé
MicroRNAs (miRs) are recognized as key molecular regulators in
most of intracellular processes essential for plant adaptation to en-
vironmental changes. microRNAs can mediate regulation of gene
expression involved in development, acquisition of nutrients, de-
fense and interactions with soil microorganisms to enhance stress
tolerance of plants. Accumulating evidences indicate that microR-
NAs are also transferred within cells, organs or whole plant and
released in soil as stress signals of the plant-microbiome commu-
nication. However, little information is available about how mobile
microRNAs are conveyed from plant to the rhizosphere. To under-
stand whether this intriguing phenomenon occurs through root
secretion, morphological and physiological changes as well as the
expression profiles of developmental and oxidative stress respon-
sive microRNAs were analyzed in root tissues and exudates col-
lected from wheat (triticum aestivum) exposed to bisphenol A at low
and high concentrations (0.1 and 5000 mg. kg -1 soil). BPA contami-
nation significantly affected aerial and root biomass, antioxidant
enzymes activities (catalase and superoxide dismutase) and mir
164, miR 167, and miR 398 expression in roots of the group that
received the highest dose. The presence of miR156, miR164, miR167
was detected in root exudates of controls and contaminated plants
while BPA exposure increased miR 167 levels exuded at high dose.
In summary, this experiment offered first results reporting a par-
ticipation of the microRNAs regulatory network in the BPA stress
response of wheat. The identification of microRNAs as integral com-
ponent of the root exudates will provide novel insights into chemi-
cal signaling in plant-soil microbiome interactions.