Increasing evidence suggests that long non-coding RNAs(lnc RNAs) play significant roles in plants.However,little is known about lnc RNAs in Panax ginseng C.A.Meyer,an economically significant medicinal plant species.A total of3,688 m RNA-like non-coding RNAs(mlnc RNAs),a class of lnc RNAs,were identified in P.ginseng.Approximately 40% of the identified mlnc RNAs were processed into small RNAs,implying their regulatory roles via small RNA-mediated mechanisms.Eleven mi RNA-generating mlnc RNAs also produced si RNAs,suggesting the coordinated production of mi RNAs and si RNAs in P.ginseng.The mlnc RNA-derived small RNAs might be 21-,22-,or 24-nt phased and could be generated from both or only one strand of mlnc RNAs,or from super long hairpin structures.A full-length mlnc RNA,termed MAR(multiple-function-associated mlnc RNA),was cloned.It generated the most abundant si RNAs.The MAR si RNAs were Researchpredominantly 24-nt and some of them were distributed in a phased pattern.A total of 228 targets were predicted for 71 MAR si RNAs.Degradome sequencing validated 68 predicted targets involved in diverse metabolic pathways,suggesting the significance of MAR in P.ginseng.Consistently,MAR was detected in all tissues analyzed and responded to methyl jasmonate(Me JA) treatment.It sheds light on the function of mlncRNAs in plants.
