Work

Thioredoxins as hormone-responsive redox regulators in wheat: transcriptomic and structural insights

Year: 2026

Type: article

Abstract: Thioredoxins (TRXs) are small central redox proteins involved in stress responses and plant development, but their hormone-dependent regulation remains poorly characterized. In this study, a genome-wide identification of the TRX family in Triticum aestivum (Ta) was performed using Arabidopsis thaliana TRXs as orthologs. Phylogenetic analysis allowed the identification of a total of 48 TRXs, including 22 typical TRXs, 22 atypical TRXs, and four thioredoxin reductases (TRs). The identified classes in wheat were conserved compared with the Arabidopsis genome; however, no extra classes were identified. To assess the regulation of the wheat TRX genes under hormonal treatments, including abscisic acid (ABA), ethylene (ET), indole-3-acetic acid (IAA), and methyl jasmonate (MeJA), an in silico analysis was performed using the GEO dataset. The transcriptomic analysis and the quantitative reverse transcription PCR (qRT-PCR) validation revealed that the atypical TRXs were more responsive to hormones than the typical TRXs and TRs . Among these atypical TRX members, atypical cysteine/histidine rich thioredoxin (ACHT), chloroplast drought stress protein of 32 kDa (CDSP32), nucleoredoxin (NRX), and TRX-L3 groups were the most hormone-responsive. ABA strongly upregulated the TaACHT4.2 gene, whereas TaNRX1.1 responded to IAA and ET. On the other hand, ABA, IAA, ET, and MeJA downregulated TaCDSP32.1 , TaNRX1.2 , TaNRX1.3 , and ACHT members. The molecular docking analysis suggested a potential interaction between the selected atypical TRXs and ABA, IAA, and MeJA. The multidomain TRXs, such as TaCDSP32.1 and TaNRX1.1, showed a high affinity for ABA and IAA, whereas TaTRX-L3.1.3 showed a high affinity for MeJA. This study highlights the importance and potential functions of poorly characterized atypical TRXs as hormone-responsive redox regulatory nodes in wheat and provides a basis for future functional validation under hormonal and stress conditions, as well as during plant development.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2026.1911123

Authors: Mohammed Hashim Bouzenita, Rana Adnan Tahir, Mengjie Fan, Aisha Shabib Estanbooli, Kamel Chibani

Institutions: Sultan Qaboos University, University of Essex

Language: English

Topic: Redox biology and oxidative stress

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $3,801