The invention relates to newly identified nucleic acids, ribonucleic acids (RNAs) and deoxyribonucleic acids (DNAs), specifically esiRNAs / ERNAs (effective small interfering RNAs) and RNAs derived therefrom, as well as eASO (effective
antisense DNA oligonucleotides), collectively referred to as eNAs (effective nucleic acids), which can be used in
RNA silencing / RNAi or
RNA silencinglantisense methods, as active agents against various variable
plant pathogens. To identify the eNAs, an “eNA screen” was applied for the first time in standardized form to target RNAs of various
plant pathogens. As a result, a new class of active agents against pathogens was identified and successfully used. The invention further relates to the construction of double-stranded ribonucleic acids, edsRNAs (effectively double-stranded RNAs), which contain
nucleotide sequences of identified esiRNAs / ERNAs or related RNAs derived therefrom, and which can be successfully used in the
RNA silencing / RNAi methods as active agents in
plant protection against variable plant pathogens.