Differential Expression of miRNAs Under Salt Stress in Spartina alterniflora Leaf Tissues

Coastal marsh habitats are impacted by many factors or disturbances, including habitat destruction, pollution, and the introduction of invasive species. Spartina alterniflora (S. alterniflora) is an important invasive species, accounting for a significant proportion of the invasive plants spread around the world. Salt stress is a major environmental stress factor, which affects plant growth and development. Little information is available regarding S. alterniflora microRNAs (miRNAs) which play important regulatory roles in plant growth and development. In order to detect S. alterniflora miRNAs and determine any expression differences between S. alterniflora plants cultivated on ordinary soils from the greenhouse and salty soils from Dafeng, in Jiangsu province of China, we carried out the detection and quantification of S. alterniflora miRNAs by microarray. Among the 81 miRNAs identified as significantly down- or up-regulated under the salt stress, 21 of the miRNAs represent 8 miRNA gene families in S. alterniflora. We found that miR168, miR399, miR395, miR393, miR171, miR396, miR169, and miR164 were down-regulated under salinity stress, and 60 of the miRNAs were up-regulated, which were revealed to be induced by salt stress in plants. The identification of differentially expressed novel plant miRNAs and their target genes, and the analysis of expression, provide molecular evidence for the possible involvement of miRNAs in the process of salt response and/or salt tolerance in S. alterniflora.