Redox regulation of glutathione peroxidase by thioredoxin in longan fruit in relation to senescence and quality deterioration. (30th May 2021)

• Record Type: Journal Article
• Authors: Wu, Fuwang; Jiang, Guoxiang; Yan, Huiling; Xiao, Lu; Liang, Hanzhi; Zhang, Dandan; Jiang, Yueming; Duan, Xuewu
• Is Part Of: Food chemistry. Volume 345(2021)
• Publication Date: 2021-05-30
• Subjects: Aril breakdown -- Quality deterioration -- Reactive oxygen species -- Redox regulation -- Thioredoxin -- Glutathione peroxidase; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.128664
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Expression of DlTrx1 and DlNRT1 were upregulated with fruit quality deterioration. Thirty-three potential Trx target proteins in longan were identified. Gpx was one target protein of Trx in longan fruit. DlTrx regulated redox state and activity of DlGpx. Redox state of DlGpx is related to fruit senescence or quality deterioration. Abstract: Thioredoxins (Trxs) are important redox regulators in organisms. However, their involvement in fruit senescence and quality deterioration remains unclear. In this study, one Trx ( DlTrx1 ) and one NADPH-dependent Trx reductase ( DlNRT1 ) cDNAs, were cloned from longan fruit. The DlTrx1 could be effectively reduced by the DlNTR1. Expression of DlTrx1 and DlNTR1 were up-regulated during fruit senescence and quality deterioration. We further identified 33 potential Trx target proteins in longan, including one glutathione peroxidase (DlGpx). DlTrx1 could physically interact with DlGpx. DlTrx1 in combination with DlNTR1 effectively activated DlGpx activity by regulating its redox state. Cys 90 in DlGPx could form a disulfide bond with either Cys 42 or Cys 71, which were the sites of redox modulation. Furthermore, DlGpx exhibited a higher ratio of disulfide bonds to sulfhydryl groups in senescent or deteriorative fruit. We propose that Trx-mediated redox regulation of DlGpx is involved in senescence or quality deterioration of harvested longan fruit.