Cloning and expression analysis of two trehalose transporter genes in Trichogramma dendrolimi

The purpose of this study was to analyze the expression patterns of two trehalose transporter genes (TdTret1 and TdTret1-2) and gene expression patterns at different developmental stages and diapause development in Trichogramma dendrolimi. This analysis aimed to provide a theoretical basis for understanding the regulation of trehalose in insects to adapt to low temperature environments and the regulatory mechanism of diapause in T. dendrolimi. Gene cloning and quantitative analysis of the two types of trehalose transporter genes indicated that TdTret1 and TdTret1-2 belong to the MFS superfamily. Amino acid sequences of trehalose transporters were compared with those of hymenoptera insects, revealing that TdTret1 and TdTret1-2 had the highest consistency with Trichogramma pretiosum, suggesting a close genetic relationship. These two trehalose transporter genes exhibited a "staggered" expression pattern in T. dendrolimi. TdTret1 was mainly expressed in the early growth stages (i.e., egg stage and larval stage), while TdTret1-2 showed significantly higher expression levels during the egg, pupal and adult stages. Both TdTret1 and TdTret1-2 were significantly upregulated in diapausing T. dendrolimi compared to non-diapausing ones, but with distinct timing; it was observed that TdTret1-2 responded more quickly to low temperatures than TdTret1. These two trehalose transporter genes play an important role in the normal development and diapause development of T. dendrolimi.