Stress-Responsive MicroRNAs in Populus

ABSTRACT: MicroRNAs (miRNAs), a group of small non-coding RNAs, have recently become a subject of intense study. They are a class of post-transcriptional, negative regulators playing vital roles in plant development and growth. However, little is known about their regulatory roles in tree’s responses to the stressful environments incurred over its long-term growth. Here, we reported the cloning of small RNAs from abiotic stressed tissues of P. trichocarpa and the identification of 68 putative miRNA sequences that can be classified into 27 families based on sequence homology. Among them, 9 families are novel, raising the number of the known ptc-miRNA families from 33 to 42. Total 346 targets are predicted for the cloned ptc-miRNAs using penalty scores of ≤2.5 for mismatched patterns in the miRNA:mRNA duplexes as the criterion. Six selected targets are experimentally validated. The expression of a majority of the novel miRNAs is altered in response to cold, heat, salt, dehydration, and mechanical stresses. Microarray analysis of known ptc-miRNAs identified 19 additional cold stress responsive ptc-miRNAs that originate from 14 miRNA gene families. Interestingly, we found that miRNAs of the same family respond differentially to the same stress. This suggests that members of a miRNA family may have different functions. These results reveal possible roles for miRNAs in the regulatory networks associated with development and stress response and therefore critical to plant long-term growth; and provide useful information for developing trees with a greater level of stress-resistance. Keywords: microRNA, cold stress, time course MicroRNA abundance of 21 samples from 7 cold stress time point were analyzed, each cold stress time point contain three replicates. 0 hour cold stress treatment were used as control.

ORGANISM(S): Populus trichocarpa

SUBMITTER: Vincent Chiang 

PROVIDER: E-GEOD-10582 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress