small RNAs sequencing in sweet sorghum under cadmium stress

Four small RNA libraries from two contrasting sweet sorghum genotypes were sequenced. In this study, One hundred and ninety-five conserved miRNAs belonging to 56 families and 25 putative novel miRNAs from 28 precursors were identified, among which 38 conserved and 24 novel miRNAs were differentially expressed under Cd stress and/or between H18 and L69. Two groups of them: miR169p/q-nov_23 and miR408 were further focused through the coexpression analysis and might be involved in Cd transport, cytoskeleton activity and cell wall construction by regulating their targets. This study presents new insights into the regulatory roles of miRNAs in Cd accumulation and tolerance in sweet sorghum and will help to develop high-Cd accumulation or high Cd-resistant germplasm of sweet sorghum through molecular breeding and/or genetic engineering approaches. Four sRNA libraries were constructed from the roots of H18 and L69 (high-Cd accumulation one H18, and low-Cd accumulation one L69) treated with 10 µM CdCl2 for 24 hours, using the plants without CdCl2 treatment as control (named H18-CK, H18-Cd, L69-CK and L69-Cd, respectively). High throughput sequencing of miRNAs was then performed.