Palauqui JC, Elmayan T, Pollien JM, et al. Systemic acquired silencing：transgene-specific post-transcriptional silencing is transmitted by grafting from silenced stocks to non-silenced scions[J]. The EMBO Journal, 1997, 16（15）：4738-4745.
[2]
Fire A, Xu SQ, Montgomery MK, et al. Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans[J]. Nature, 1998, 391（6669）：806-811.
[3]
van Bel AJE. The phloem, a miracle of ingenuity[J]. Plant, Cell & Environment, 2003, 26（1）：125-149.
[4]
Buhtz A, Springer F, Chappell L, et al. Identification and characterization of small RNAs from the phloem of Brassica napus[J]. The Plant Journal, 2008, 53（5）：739-749.
[5]
Chen X. MicroRNA biogenesis and function in plants[J]. FEBS Letters, 2005, 579（26）：5923-5931.
[6]
Pant BD, Buhtz A, Kehr J, et al. MicroRNA399 is a long-distance signal for the regulation of plant phosphate homeostasis[J]. The Plant Journal, 2008, 53（5）：731-738.
[7]
Schwach F, Vaistij FE, Jones L, et al. An RNA-dependent RNA polymerase prevents meristem invasion by potato virus X and is required for the activity but not the production of a systemic silencing signal[J]. Plant Physiology, 2005, 138：1842-1852.
[8]
B?urle I, Smith L, Baulcombe DC, et al. Widespread role for the flowering-time regulators FCA and FPA in RNA-mediated chromatin silencing[J]. Science, 2007, 318（5847）：109-112.
[9]
Borsani O, Zhu J, Verslues PE, et al. Endogenous siRNAs derived from a pair of natural cis-antisense transcripts regulate salt tolerance in Arabidopsis[J]. Cell, 2005, 123（7）：1279-1291.
[10]
Vatén A, Dettmer J, Wu S, et al. Callose biosynthesis regulates symplastic trafficking during root development[J]. Dev Cell, 2011, 21（6）：1144-1155.
[11]
Ariel FD, Manavella PA, Dezar CA, et al. The true story of the HD-Zip family[J]. Trends in Plant Sci, 2007, 12（9）：419-426.
[12]
Carlsbecker A, Lee JY, Roberts CJ, et al. Cell signalling by microRNA165/6 directs gene dose-dependent root cell fate[J]. Nature, 2010, 465（7296）：316-321.
[13]
Montgomery TA, Howell MD, Cuperus JT, et al. Specificity of ARGONAUTE7-miR390 interaction and dual functionality in TAS3 Trans-acting siRNA formation[J]. Cell, 2008, 133：128-141.
[14]
Benkovics AH, Timmermans MCP. Developmental patterning by gradients of mobile small RNAs[J]. Current Opinion in Genetics & Development, 2014, 27：83-91.
[15]
Mosher RA, Melnyk CW. siRNAs and DNA methylation：seedy epigenetics[J]. Trends Plant Sci, 2010, 15（4）：204-210.
[16]
Winston WM, Molodowitch C, Hunter CP. Systemic RNAi in C. elegans requires the putative transmembrane protein SID-1[J]. Science, 2002, 295（5564）：2456-2459.
[17]
Hinas A, Wright AJ, Hunter CP. SID-5 is an endosome-associated protein required for efficient systemic RNAi in C. elegans[J]. Current Biology, 2012, 22（20）：1938-1943.
[18]
Molnar A, Melnyk CW, Bassett A, et al. Small silencing RNAs in plants are mobile and direct epigenetic modification in recipient cells[J]. Science, 2010, 328（5980）：872-875.
[19]
Dunoyer P, Schott G, Himber C, et al. Small RNA duplexes function as mobile silencing signals between plant cells[J]. Science, 2010, 328（5980）：912-916.
[20]
Brosnan CA, Mitter N, Christie M, et al. Nuclear gene silencing directs reception of long-distance mRNA silencing in Arabidopsis[J]. Proc Natl Acad Sci USA, 2007, 104（37）：14741-14746.
[21]
Zhai J, Zhao Y, Simon SA, et al. Plant microRNAs display differential 3'' truncation and tailing modifications that are ARGONAUTE1 dependent and conserved across species[J]. The Plant Cell Online, 2013, 25（7）：2417-2428.
[22]
Rogers K, Chen X. Biogenesis, turnover, and mode of action of plant microRNAs[J]. Plant Cell, 2013, 25（7）：2383-2399.
[23]
Zhu H, Hu F, Wang R, et al. Arabidopsis argonaute10 specifically sequesters miR166/165 to regulate shoot apical meristem development[J]. Cell, 2011, 145（2）：242-256.
[24]
Brunkard JO, Runkel AM, Zambryski PC. Plasmodesmata dynamics are coordinated by intracellular signaling pathways[J]. Current Opinion in Plant Biology, 2013, 16（5）：614-620.
[25]
Liarzi O, Epel BL. Development of a quantitative tool for measuring changes in the coefficient of conductivity of plasmodesmata induced by developmental, biotic, and abiotic signals[J]. Protoplasma, 2005, 225（1-2）：67-76.
[26]
Guo HS, Ding SW. A viral protein inhibits the long range signaling activity of the gene silencing signal[J]. The EMBO Journal, 2002, 21（3）：398-407.
[27]
Zhang X, Yuan YR, Pei Y, et al. Cucumber mosaic virus-encoded 2b suppressor inhibits Arabidopsis Argonaute1 cleavage activity to counter plant defense[J]. Genes Dev, 2006, 20：3255-3268.
[28]
Voinnet O, Baulcombe DC. Systemic signalling in gene silencing[J]. Nature, 1997, 389（6651）：553.
[29]
Yoo BC, Kragler F, Varkonyi-Gasic E, et al. A systemic small RNA signaling system in plants[J]. The Plant Cell Online, 2004, 16（8）：1979-2000.
[30]
Lin SI, Chiang SF, Lin WY, et al. Regulatory network of microRNA399 and PHO2 by systemic signaling[J]. Plant physiology, 2008, 147（2）：732-746.
[31]
Ding SW, Voinnet O. Antiviral immunity directed by small RNAs[J]. Cell, 2007, 130（3）：413-426.
[32]
Burgyán J, Havelda Z. Viral suppressors of RNA silencing[J]. Trends in Plant Science, 2011, 16（5）：265-272.
[33]
Herr AJ, Jensen MB, Dalmay T, et al. RNA polymerase IV directs silencing of endogenous DNA[J]. Science, 2005, 308：118-120.
[34]
Melnyk CW, Molnar A, Baulcombe DC. Intercellular and systemic movement of RNA silencing signals[J]. The EMBO Journal, 2011, 30（17）：3553-3563.
[35]
Jones L. Revealing micro-RNAs in plants[J]. Trends in Plant Science, 2002, 7（11）：473-475.
[36]
Furuta K, Lichtenberger R, Helariutta Y. The role of mobile small RNA species during root growth and development[J]. Current Opinion in Cell Biology, 2012, 24（2）：211-216.
[37]
Husbands AY, Chitwood DH, Plavskin Y, et al. Signals and prepatterns：new insights into organ polarity in plants[J]. Genes & Development, 2009, 23（17）：1986-1997.
[38]
Allen E, Xie Z, Gustafson AM, et al. microRNA-directed phasing during Trans-acting siRNA biogenesis in plants[J]. Cell, 2005, 121（2）：207-221.
[39]
Chitwood DH, Nogueira FTS, Howell MD, et al. Pattern formation via small RNA mobility[J]. Genes & Development, 2009, 23（5）：549-554.
[40]
Nogueira FTS, Madi S, Chitwood DH, et al. Two small regulatory RNAs establish opposing fates of a developmental axis[J]. Genes & Development, 2007, 21（7）：750-755.
[41]
Knauer S, Holt AL, Rubio-Somoza I, et al. A protodermal miR394 signal defines a region of stem cell competence in the Arabidopsis shoot meristem[J]. Dev Cell, 2013, 24（2）：125-132.
[42]
Song JB, Huang SQ, Dalmay T, et al. Regulation of leaf morphology by microRNA394 and its target LEAF CURLING RESPONSIVENESS[J]. Plant and Cell Physiology, 2012, 53（7）：1283-1294.
[43]
Slotkin RK, Vaughn M, Borges F, et al. Epigenetic reprogramming and small RNA silencing of transposable elements in pollen[J]. Cell, 2009, 136（3）：461-472.
[44]
Winston WM, Sutherlin M, Wright AJ, et al. Caenorhabditis elegans SID-2 is required for environmental RNA interference[J]. Proc Natl Acad Sci USA, 2007, 104（25）：10565-10570.
[45]
Varkonyi-Gasic E, Gould N, Sandanayaka M, et al. Characterisation of microRNAs from apple（Malus domestica’Royal Gala’）vascular tissue and phloem sap[J]. BMC Plant Biology, 2010, 10（1）：159.
Juarez MT, Kui JS, Thomas J, et al. microRNA-mediated repression of rolled leaf1 specifies maize leaf polarity[J]. Nature, 2004, 428（6978）：84-88.
[48]
de Felippes FF, Ott F, Weigel D. Comparative analysis of non-autonomous effects of tasiRNAs and miRNAs in Arabidopsis thaliana[J]. Nucleic Acids Research, 2011, 39：2880-2889.
[49]
Ameres SL, Horwich MD, Hung JH, et al. Target RNA-directed trimming and tailing of small silencing RNAs[J]. Science, 2010, 328（5985）：1534-1539.
[50]
Park MY, Wu G, Gonzalez-Sulser A, et al. Nuclear processing and export of microRNAs in Arabidopsis[J]. Proc Natl Acad Sci USA, 2005, 102（10）：3691-3696.
[51]
Liu Q, Yao X, Pi L, et al. The ARGONAUTE10 gene modulates shoot apical meristem maintenance and establishment of leaf polarity by repressing miR165/166 in Arabidopsis[J]. The Plant Journal, 2009, 58（1）：27-40.
[52]
Voinnet O, Vain P, Angell S, et al. Systemic spread of sequence-specific transgene RNA degradation in plants is initiated by localized introduction of ectopic promoterless DNA[J]. Cell, 1998, 95（2）：177-187.
[53]
Chitwood DH, Timmermans MCP. Small RNAs are on the move[J]. Nature, 2010, 467（7314）：415-419.
[54]
Shapiro E, Biezuner T, Linnarsson S. Single-cell sequencing-based technologies will revolutionize whole-organism science[J]. Nature Reviews Genetics, 2013, 14（9）：618-630.
