GSE69572
Novel and Conserved microRNAs in soybean floral whorls
MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs (19–24 nt) that regulates de gene expression, mainly through mRNA targets cleavage and translation inhibition. In plants, miRNAs have been shown to play pivotal roles in a wide variety of metabolic and biological processes like plant growth, development, and response to biotic and abiotic stress. Soybean is one of the most important crops worldwide, due to the production of oil and its high protein content. The reproductive phase is considered the most important for the yield of soybean, which is mainly intended to produce the grains. The identification of miRNAs is not yet saturated in soybeans, and there are no studies linking them to the different floral organs. In this study, three different soybean floral whorls were used in the construction of sRNA libraries. The sequencing of petal, carpel and stamen libraries by the Solexa platform generated a total of 10,165,661 sequences. Subsequently analyses detected 200 miRNAs sequences, from those 41 were novel miRNAs never detected before, 80 were conserved soybean miRNAs, 31 were new antisense conserved soybean miRNAs and 46 soybean miRNAs isoforms. We also found a new miRNA conserved in other plant species, and finally one miRNA-sibling of a soybean conserved miRNA. Conserved and novel miRNAs were evaluated by RT-qPCR. We observed a differential expression across the three whorls for six miRNAs analyzed. A computational prediction of targets for miRNAs analyzed by RT-qPCR was performed. Many of the predicted targets have described functions related to the reproductive process in plants. In summary, the increased accumulation of specific and novel miRNAs in different whorls indicates that miRNAs are an important part of the regulatory network in soybean flower. Overall design: microRNA profiles in 4 different libraries (stamens, petals, carpels and whole flower) of Glycine max by deep sequencing (Illumina HiSeq2000).