Identification and comparative profiling of microRNAs in wild-type Xanthoceras sorbifolia and its double flower mutant

Abstract

MicroRNAs are small, non-coding RNAs that regulate gene expression post-transcriptionally and have crucial roles in plant biological and metabolic processes. To date, there has been no report concerning miRNAs in Xanthoceras sorbifolia, one of the most important woody energy plants for biofuel production. To study the roles of miRNAs during floral organ differentiation and development in X. sorbifolia, two small RNA libraries were constructed from the flower buds of simple flowers (wild-type) and double flowers (mutant). Each library was sequenced individually and generated over 33 million raw reads in total. Forty-three conserved miRNAs belonging to 30 families and 10 novel miRNAs were identified. The expressions of a selected group of conserved and novel miRNAs were validated by qRT-PCR. Target gene prediction identified 230 target genes for most of the conserved and novel miRNAs. Fifteen miRNAs were demonstrated to be differentially expressed between wild-type and mutant. This is the first study to identify conserved and novel miRNAs and profile their expression changes during floral organ differentiation and development in X. sorbifolia.