Identification of novel and salt-stress-regulated miRNAs from root of Melilotus officinalis (L.) Pall. by qRT-PCR

Abstract

Abstract Salinity is regarded as the main environmental stress, which affects plant growth and physiological functions. miRNAs play crucial roles in plants salt stress response. Melilotus officinalis (L.) Pall. (MO) is an excellent forage and honey plant. In addition to its high medicinal values and outstanding ecological effects, MO also has the ability of salt tolerance. However, the miRNA expression mechanism of MO in response to salt stress is still unclear. To reveal the salt tolerance related miRNAs and predict their target genes in MO, we extracted a small RNA library from the roots of MO seedlings without salt treatment and used 300 mM NaCl treated roots of MO seedlings to construct another small RNA library. We identified 93 novel and 98 known miRNAs in control, 100 novel and 115 known miRNAs in case. 27 up-regulation and 20 down-regulated miRNAs were selected, 466 potential target miRNAs and 520 sites were predicted by differential expression analysis. 9 miRNAs were verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Our findings summary the miRNAs and their targets for regulating salt defense reactions in MO. The discussion will be helpful to study the molecular mechanisms of salt resistance of MO and other Leguminosae species.