干旱区生态环境知识资源中心

Azadirachtin, a neem seed terpenoid is effective against serious lepidopteran crop pests like Plutella xylostella and Spodoptera litura. The mode of action of azadirachtin and its cellular target in insects has been largely unexplored, although physiological and morphological defects have been documented. Understanding the mechanism of action of this complex natural molecule at the cellular level is crucial to define safety and entomo-specific affinity. Actin has been recently indicated as a putative target of azadirachtin in vivo and in silico using Drosophila melanogaster. In this communication, the target of azadirachtin in Plutella and Drosophila has been validated by in vitro polymerization assays of actin and its mRNA transcript profiles of Act5C, a ubiquitous cytoplasmic and Act57B, a muscle-specific isoform. Further, phalloidin labelling of Spodoptera haemocytes identifies the exact passage of azadirachtin on the highly proliferating developmental tissues.