Functional analysis of trehalose metabolism genes reveals developmental vulnerability and metabolic plasticity in Bemisia tabaci

Trehalase plays a crucial role in regulating various physiological activities in insects, such as energy metabolism and temperature stress tolerance; however, its function in the MED species of Bemisia tabaci remains poorly understood. This study systematically investigated the regulation of trehalose metabolism in B. tabaci MED using RNAi and pharmacological interventions. Developmental profiling revealed stage-specific upregulation of trehalase genes BtTre and BtTPS1, peaking in adults. Tissue-specific expression showed BtTre1 and BtTPS1 were highest in the fat body, while BtTre2 was highest in the gut. RNAi targeting BtTre1 achieved 62.68% silencing efficiency, causing 34% downregulation of BtTPS1 suppressing trehalase activity, and disruping energy homeostasis, leading to significant stage-dependent of 77% at 120 h. Validamycin treatment suppressed trehalase activity but increased trehalose content, whereas starvation induced the opposite effects, demonstrating metabolic plasticity. BtTre1 silencing in adults disrupted energy homeostasis more severely than in nymphs, suggesting a developmental vulnerability. These findings not only elucidate the essential role of trehalose metabolism in B. tabaci physiology but also identify BtTre1 as a promising RNAi target and confirm the significant inhibitory effect of validamycin on BtTre1 genes. The contrasting effects of pharmacological and nutritional perturbations provide insights into the design of combined control strategies.