| 【Objective】MicroRNAs (miRNAs) are a class of endogenous, single-stranded and non-coding small
RNA molecules that are involved in the regulation of gene expression after transcription in plants and animals. Vco-miR_
n10 is a novel miRNA in blueberry, and its function remains unknown. In the present study, a preliminary functional analysis
of blueberry Vco-miR_n10 was carried out.【Method】Based on the previous data from high throughput sequencing of
small RNA in blueberry, the precursor sequence (224 nt) of the novel miRNA (Vco-miR_n10) was cloned and sequenced.
The secondary structure of its precursor sequence was predicted by mfold web server. The expression vector, 35Spro::preVco-miR_n10, was constructed by Gateway system and transferred into wild type Arabidopsis thaliana and its phenotype
under the conditions of normal growth and 300 mmol/L mannitol treatment was observed and analyzed, respectively.【Result】
The precursor sequence of Vco-miR_n10 was obtained by cloning, and structure analysis indicated that the precursor shows
near-perfect stem-loop structure with no more than 2 mismatches. In addition, the mature sequence was located on the 3’stem arm. No significant phenotypic variation was observed in transgenic plants under the normal growth condition. However, under
the drought condition simulated by 300 mmol/L mannitol, the germination rate (33.53%, 37.69%) and cotyledon greening rate
(33.53%, 37.69%) of two transgenic lines (Vco-miR_n10-24 and Vco-miR_n10-52) were significantly lower than those of
wild type A. thalian (germination rate: 67.72%; cotyledon greening rate:66.33%).【Conclusion】These results indicated that
blueberry Vco-miR_n10 could respond to the mannitol-simulated drought stress, and reduce the drought tolerance in A. thalian
through affecting seed germination and cotyledon greening, which showed that blueberry Vco-miR_n10 might play a regulatory
role in plant response to drought stress. |
