Panax notoginseng Transcriptome or Gene expression

Plant genomes encode several kinds of small regulatory RNAs (sRNAs), such as microRNAs (miRNAs), and trans-acting small interfering RNAs (tasiRNAs), that play critical roles in both development and stress responses. Panax notoginseng (Burk.) F.H. Chen (P. notoginseng) is an important traditional Chinese herbal medicine for its haemostatic effects. The yield of roots of P. notoginseng is a major concern since the roots of P. notoginseng are the parts used to produce medicine. To identify sRNAs that are critical for the weights of P. notoginseng roots, we perform a comprehensive study of miRNA transcriptomes from P. notoginseng roots of different weights. We identify 700 conserved miRNAs, of which 180 precursors are also identified. Our results show there are at least three TAS3 loci in P. notoginseng. By using degradome sequencing, we identified 165 conserved miRNA:target or tasiRNA:target relations, as well as some novel miRNA:target pairs. More importantly, our results show that several miR156 family members have higher expression levels in P. notoginseng roots of larger weights. These results provide a comprehensive view of miRNA and tasiRNA transcriptomes in P. notoginseng and offer clues that the might be useful for breeding of P. notoginseng.