Next-Generation Sequencing Sheds New Light on Small RNAs in Plant Reproductive Development

Reproductive development is a key step of the plant life cycles and indicates the start of a new life cycle. The reproductive organs including flower, fruit and seed, have diverse and complex structures, which is a syndrome in the evolution of angiosperms. The development of plant reproductive organs depends on the correct spatial and temporal expression of numerous genes acting in concert to form regulatory networks. Small non-coding RNAs (sRNAs) play a key role in the reproductive development through different modes of sequence-specific interaction with their targets. The sRNAs guide transcriptional and post-transcriptional regulation to intensively integrate into the complex process. Next-generation sequencing (NGS) techniques have greatly extended the scientist’s capabilities to identify and quantify sRNAs by supplying a massive number of sequences. In turn this has led to a greater understanding of the many complex roles and interactions that sRNAs are involved with during reproductive development. In this review, we provide an overview of the biogenesis and classification of plant sRNAs, and summarize the recent progress in the understanding of plant sRNA in the flower, and fruit/seed development. Also, we discuss NGS approaches to profile global sRNA expression, as well as the application of sRNAseq/ degradome-seq approaches to identify novel sRNAs and verify their targets related to the above development processes.