ELECTROPORATION OF SMALL RNAS INTO PLANT-PROTOPLASTS - MITOCHONDRIAL UPTAKE OF TRANSFER-RNAS

To study tRNA import into plant mitochondria, we have set up a system to follow the fate in vivo of tRNA transcripts introduced into plant p rotoplasts by electroporation. Conditions were optimized for maximum t RNA uptake into potato protoplasts. We have shown that in vitro synthe sized tRNA transcripts are poor substrates due to rapid degradation le ading to low efficiencies of transfer and short life in protoplasts. L abelled natural tRNAs were more efficiently electroporated into protop lasts and they remained stable during protoplast culture. We have obse rved import into mitochondria of total and purified cytosolic tRNAs in protoplasts bur the process was not specific for the tRNA species whi ch are normally imported. (C) 1996 Academic Press, Inc.