GSE107056
miRNAs related to silique development in Brassica napus
MicroRNAs (miRNAs) are a class of non-coding small RNAs (sRNAs) that play crucial regulatory roles in various developmental processes. Silique length indirectly influences seed yield in rapeseed (Brassica napus); however, the molecular roles of miRNAs in silique length are largely unknown. Here, backcross progenies of rapeseed with long siliques (LS) and short siliques (SS) were used to elucidate this role. Four small RNA libraries from early developing siliques were sequenced, and a total of 814 non-redundant miRNA precursors were identified, representing 65 known miRNAs, and 394 novel miRNAs. Expression analyses revealed 12 known miRNAs and 5 novel miRNAs that were differentially expressed in LS and SS lines. Furthermore, though two degradome sequencing, we annotated 522 cleavage events. An analysis of correlated expression between differentially expressed miRNAs and their targets demonstrated that some transcription factors might repress cell proliferation or auxin signal transduction to control silique length, and that a Pi/Cu deficiency might also restrict silique development. More significantly, the overexpression of miR160 in rapeseed may repress auxin response factors and result in increased silique length, illustrating that silique length could be regulated via an auxin-response pathway. These results will serve as a foundation for future research in B. napus. Overall design: The aim of the present study was to systematically identify miRNAs that may be involved in early silique development.