Role of digestive protease enzymes and related genes in host plant adaptation of a polyphagous pest, <i>Spodoptera frugiperda</i>

The evolutionary success of phytophagous insects depends on their ability to efficiently exploit plants as a source energy for survival. Herbivorous largely depend the efficiency, flexibility, and diversity digestive physiology sophistication detoxification system use chemically diverse host food sources. fall armyworm, Spodoptera frugiperda (J.E. Smith), is polyphagous pest many commercially important crops. To elucidate this insect adapt plant mechanisms, we evaluated impact primary (corn) alternate (rice) after 11 generations gut enzymatic activity expression profiles related genes. Results indicated that total protease class-specific trypsin- chymotrypsin-like S. significantly differed among treatments. greatly in midguts upon larval exposure different treatments with inhibitors compared without inhibitors. Similarly, single cumulative effects enzyme-specific TLCK, TPCK, E-64 increased mortality reduced growth/mass across Furthermore, quantitative reverse transcription polymerase chain reaction results revealed two trypsin (SfTry-3, SfTry-7) one chymotrypsin gene (Sfchym-9), which they have roles adaptation. Knockdown these genes resulted mRNA levels This was observed dsRED control. result indicates possible enzymes