MicroRNAs (
miRNAs) play profound roles in plant growth and development by regulating gene expression.
Tetraploid plants often have better physical characteristics and stress tolerance than their diploid progenitors, but the role of
miRNAs in this superiority is unclear. Paulownia tomentosa, (Paulowniaceae) is attracting research attention in China because of its rapid development, wide distribution, and potential economic uses. To identify
miRNAs at the transcriptional level in P. tomentosa, Illumina sequencing was used to sequence the libraries of diploid and
tetraploid plants. Sequence analysis identified 37 conserved
miRNAs belonging to 14
miRNA families and 14 novel
miRNAs belonging to seven
miRNA families. Among the
miRNAs, 16 conserved
miRNAs from 11 families and five novel
miRNAs were differentially expressed in the
tetraploid and diploid; most were more strongly expressed in the former. The
miRNA target genes and their functions were identified and discussed. The results showed that several P. tomentosa
miRNAs may play important roles in the improved traits seen in
tetraploids. This study provides a foundation for understanding the regulatory mechanisms of
miRNAs in
tetraploid trees.