Chromatin-Remodelling ATPases ISWI and BRM Are Essential for Reproduction in the Destructive Pest Tuta absoluta

The tomato leaf miner (Tuta absoluta) is one of the top 20 plant pests worldwide. We cloned and identified the chromatin-remodelling ATPase genes ISWI and BRM by RACE and bioinformatic analysis, respectively; used RT-qPCR to examine their expression patterns during different life cycle stages; and elucidated their roles in insect reproduction using double-stranded RNA injections. The full-length cDNA of TaISWI was 3428 bp and it encoded a 1025-aa polypeptide. The partial-length cDNA of TaBRM was 3457 bp and it encoded a 1030-aa polypeptide. TaISWI and TaBRM were upregulated at the egg stage. Injection of TaISWI or TaBRM dsRNA at the late pupa stage significantly inhibited adult ovary development and reduced fecundity, hatchability, and longevity in the adult females. To the best of our knowledge, the present study was the first to perform molecular characterisations of two chromatin-remodelling ATPase genes and clarify their roles in T. absoluta fecundity. Chromatin-remodelling ATPases are potential RNAi targets for the control of T. absoluta and other insect pests. The present study was also the first to demonstrate the feasibility of reproductive inhibitory RNAi as a putative approach for the suppression of T. absoluta and other Lepidopteran insect populations.