基金The NCCR RNA and disease funded by the Swiss National Science Foundation （SNF 51NF40_141735） for access to the Biomolecular NMR spectrometry platform at ETH ZUrich. This work was supported by an IIF Marie Curie fellowship to TI （no. 329029） and a European Research Council （ERC） advanced grant ＂Frontiers of RNAi-Ⅱ＂ to OV （no. 323071）.
基金This research was supported in part by the Special Fund for Agro-scientific Research in the Public In- terest （201203038）, the Natural Science Foundation of Chongqing （CSTC, 2013jjB0176）, the earmarked fund for Modern Agro-industry （Citrus） Technology Research System, and the Foundation Project of Southwest Univer- sity （SWU114049）. We thank Kun Zhang for his technical assistance in this study.