Identification of microRNA158 from Anthurium andraeanum and Its Function in Cold Stress Tolerance

Anthurium andraeanum is a tropical flower with high ornamental and economic value. Cold stress is one of the major abiotic stresses affecting the quality and value of A. andraeanum; thus, improving the cold tolerance of this species is an important breeding objective. MicroRNAs (miRNAs) have a critical role in plant abiotic stress responses, but their specific molecular regulatory mechanisms are largely unknown, including those related to the cold stress response in A. andraeanum. Here, we identified and cloned the precursor of miR158 from A. andraeanum (Aa-miR158). Both Aa-miR158 and its target gene (c48247) had higher expression levels in strong leaves than in other tissues or organs. Further study revealed that the transcript level of Aa-miR158 was increased by cold stress. Heterologous overexpression of Aa-miR158 improved cold stress tolerance in Arabidopsis, which was associated with decreases in the malondialdehyde (MDA) concentration and relative electrical conductivity (REC) as well as increases in peroxidase (POD) and catalase (CAT) activity. Moreover, overexpressing Aa-miR158 significantly increased the expression of endogenous genes related to cold stress tolerance and reactive oxygen species (ROS) levels in transgenic Arabidopsis under cold stress. Overall, our results demonstrate that Aa-miR158 is significantly involved in the cold stress response and provide a new strategy for cold tolerance breeding of A. andraeanum.