Long noncoding RNA-based drought regulation in the important medicinal plant Dendrobium huoshanense

Dendrobium is a drought-adapted plant extensively used in traditional Chinese medicine. Long noncoding RNAs (lncRNAs) are known to control many aspects of plant physiology. Their roles in medicinal plants such as in Dendrobium are, however, not documented. Here, we investigated the lncRNAs and their targets in drought-treated Dendrobium huoshanense using strand-specific RNA-sequencing. From these data, we identified 15,224 novel lncRNAs and 17,056 known and 30,282 novel protein-coding genes. The lncRNA were shorter than the mRNAs and were also expressed at lower levels, with modulations in their expression during drought stress indicative of their putative roles in the drought response. The coexpression of differentially expressed lncRNAs and their targets was analyzed, and their potential functions identified by Gene Ontology annotation. Importantly, further analysis indicated the lncRNAs acted by influencing MAPK signaling lncRNAs. This is the first comprehensive investigation of Dendrobium lncRNAs in drought tolerance and furthers our understanding of plant lncRNAs.