AUTHOR=Shen Zhongjian , Luo Qiaozhi , Mao Jianjun , Li Yuyan , Wang Mengqing , Zhang Lisheng 

TITLE=Molecular identification of two thioredoxin genes and their function in antioxidant defense in Arma chinensis diapause

JOURNAL=Frontiers in Physiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1440531

DOI=10.3389/fphys.2024.1440531

ISSN=1664-042X

ABSTRACT=<p>Thioredoxin (Trx), an important part of thioredoxin systems, plays crucial role in maintaining the intracellular redox balance by scavenging reactive oxygen species (ROS). However, few Trxs have been functionally characterized in <italic>Arma chinensis</italic>, especially in diapause. In this study, diapause induction condition promoted hydrogen peroxide accumulation and increased CAT enzymatic activity and ascorbate content, suggesting that <italic>A. chinensis</italic> was exposed to high level of ROS. Therefore, we identified <italic>AcTrx2</italic> and <italic>AcTrx-like</italic>, and investigated the relationship with antioxidant defense. It was found that <italic>AcTrx2</italic> expression was significantly induced, whereas <italic>AcTrx-like</italic> expression was the highest on day 10 under diapause conditions. The expression of <italic>AcTrx2</italic> and <italic>AcTrx-like</italic> in fat body, a central metabolic organ of resisting oxidative stress, was significantly increased under diapause conditions, and was significantly improved by 5/15°C (diapause temperature). We investigated the knockdown of <italic>AcTrx2</italic> and <italic>AcTrx-like</italic> in <italic>A. chinensis</italic> and found that some selected antioxidant genes were upregulated, indicating that the upregulated genes may be functional compensation for <italic>AcTrx2</italic> and <italic>AcTrx-like</italic> silencing. We also found that the enzymatic activities of SOD and CAT, and the metabolite contents of hydrogen peroxide, ascorbate increased after <italic>AcTrx2</italic> and <italic>AcTrx-like</italic> knockdown. These results suggested the <italic>AcTrx2</italic> and <italic>AcTrx-like</italic> may play critical roles in antioxidant defense of <italic>A. chinensis</italic> diapause.</p>