Project description:MicroRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) play an important role in plant stress responses but the small RNA (sRNA) repertoire is poorly characterized in extremphophiles. We report sRNA transcriptomes of leaf and flower tissues of two mangrove species Bruguiera gymnorrhiza and Kandelia candel (Rhizophoraceae) based on Illumina sequencing. A total of 32 known and 5 novel miRNA families were identified collectively.Besides the conserved miR390-TAS3-ARF pathway, B. gymnorrhiza possessed additional high-abundance tasiRNAs derived from the less-conserved regions of TAS3 transcripts with expanded potential targets.his study provides the first comprehensive sRNA transcriptome for mangroves B. gymnorrhiza and K. candel. Comparative analyses revealed that these two species systematically optimize sRNA expression levels, accompanied with rewiring of sRNA regulatory networks, as an evolutionarily strategy for stress adaptations. Furthermore, 24-nt sRNAs mapped to the telomeric repeats (CCCTAAA)n were highly abundant in both B. gymnorrhiza and K. candel.
