VIROIDS VERSUS INSECTS

RNA INTERFERENCE (RNAI) IS A MECHANISM OF GENE REGULATION AND DEFENSE AGAINST EXOGENOUS AND ENDOGENOUS GENETIC ELEMENTS THAT IS TRIGGERED BY THE PRESENCE OF DOUBLE-STRANDED RNA (DSRNA) AND CULMINATES WITH THE SILENCING OF HOMOLOGOUS GENES. IN NEMATODES AND ARTHROPODS, RNAI HAS AWAKED GREAT BIOTECHNOLOGICAL INTEREST SINCE IT HAS BEEN DEMONSTRATED THE POSSIBILITY TO SILENCE GENES THROUGH THE SIMPLE INGESTION OF HOMOLOGOUS DSRNA. IF THE APPROPRIATE GENES ARE CHOSEN, SILENCING LEADS TO A HIGHLY SPECIFIC PEST CONTROL THAT IT IS EASILY ADAPTABLE TO EMERGING PESTS. HOWEVER, ARTHROPODS, UNLIKE NEMATODES, LACK THE RNAI SIGNAL-AMPLIFICATION MECHANISMS BASED ON THE RNA-DEPENDENT RNA POLYMERASE ACTIVITY AND REQUIRE SIGNIFICANT AMOUNTS OF DSRNA TO ACHIEVE AN ADEQUATE PESTICIDAL EFFECT. IN KILLERVIROID WE WANT TO EXPLORE THE POSSIBILITY OF ADAPTING A RECOMBINANT RNA EXPRESSION SYSTEM IN ESCHERICHIA COLI THAT WE HAVE RECENTLY DEVELOPED TO PRODUCE INDUSTRIAL AMOUNTS OF CIRCULAR DOUBLE-STRANDED MINIRNA PESTICIDES. WE WILL EXPLORE WHETHER THE INTRODUCTION OF TWO GROUP I AUTOCATALYTIC INTRONS (THE SECOND OF THEM WITH INTRON-EXON PERMUTATION) ALLOWS THE PRODUCTION OF THE REMARKABLE QUANTITIES OF CIRCULAR DOUBLE-STRANDED MINIRNA PESTICIDES THAT WILL BE NEEDED TO JUMP FROM THE LABORATORY TO THE INDUSTRY. THE RESEARCH WILL FOCUS ON THE GENE SNAKESKIN1 (SSJ1) OF THREE IMPORTANT INSECT PESTS: CERATITIS CAPITATA, DIABROTICA VIRGUIFERA AND TUTA ABSOLUTA, WHICH AFFECT FRUIT, CORN AND TOMATO CROPS, RESPECTIVELY. IF SUCCESSFUL, KILLERVIROID WILL OFFER THE PRODUCTIVE SECTOR OF AGRICULTURAL BIOTECHNOLOGY THE POSSIBILITY OF PRODUCING A NEW GENERATION OF HIGHLY SPECIFIC PESTICIDES, RESPECTFUL WITH THE ENVIRONMENT AND EASILY ADAPTABLE TO EMERGING NEW PESTS OF ARTHROPODS AND NEMATODES.