A long noncoding RNA involved in rice reproductive development by negatively regulating osa-miR160

Long noncoding RNAs (lncRNAs) participate in the regulation of multiple biological processes via diverse manners, one of which is functioning as endogenous target mimics (eTMs) to modulate microRNAs (miRNAs) by competing for their targets. Previously, we have predicted one lncRNA (osa-eTM160) as an endogenous repressor of osa-miR160 and validated the target mimicry ability of osa-eTM160 for ath-miR160 in Arabidopsis thaliana, yet the functions of osa-eTM160 in rice remain obscure. Here, we demonstrated that osa-eTM160 attenuated the repression of osa-miR160 on osa-ARF18 mRNAs during early anther developmental stages through the target mimicry manner, therefore to regulate rice seed setting and seed size. These findings revealed the roles of osa-eTM160 in rice, and indicated that lncRNAs with eTM functions may serve as temporal regulators to modulate the effects of miRNAs at specific developmental stages.