AUTHOR=Yang Hong-Jia , Cui Meng-Yao , Zhao Xiao-Hui , Zhang Chun-Yu , Hu Yu-Shuo , Fan Dong 

TITLE=Trehalose-6-phosphate synthase regulates chitin synthesis in Mythimna separata

JOURNAL=Frontiers in Physiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2023.1109661

DOI=10.3389/fphys.2023.1109661

ISSN=1664-042X

ABSTRACT=<p>Trehalose is a substrate for the chitin synthesis pathway in insects. Thus, it directly affects chitin synthesis and metabolism. Trehalose-6-phosphate synthase (TPS) is a crucial enzyme in the trehalose synthesis pathway in insects, but its functions in <italic>Mythimna separata</italic> remain unclear. In this study, a <italic>TPS</italic>-encoding sequence in <italic>M. separata</italic> (<italic>MsTPS</italic>) was cloned and characterized. Its expression patterns at different developmental stages and in diverse tissues were investigated. The results indicated that <italic>MsTPS</italic> was expressed at all analyzed developmental stages, with peak expression levels in the pupal stage. Moreover, <italic>MsTPS</italic> was expressed in the foregut, midgut, hindgut, fat body, salivary gland, Malpighian tubules, and integument, with the highest expression levels in the fat body. The inhibition of <italic>MsTPS</italic> expression <italic>via</italic> RNA interference (RNAi) resulted in significant decreases in the trehalose content and TPS activity. It also resulted in significant changes in <italic>Chitin synthase</italic> (<italic>MsCHSA</italic> and <italic>MsCHSB</italic>) expression, and significantly decrease the chitin content in the midgut and integument of <italic>M. separata</italic>. Additionally, the silencing of <italic>MsTPS</italic> was associated with a significant decrease in <italic>M. separata</italic> weight, larval feed intake, and ability to utilize food. It also induced abnormal phenotypic changes and increased the <italic>M. separata</italic> mortality and malformation rates. Hence, <italic>MsTPS</italic> is important for <italic>M. separata</italic> chitin synthesis. The results of this study also suggest RNAi technology may be useful for enhancing the methods used to control <italic>M. separata</italic> infestations.</p>