[Molecular and biochemical analysis of two genes encoding dehydroascorbate reductase in common wheat]

Area of Science:

• Plant molecular biology
• Enzymology
• Biochemistry

Context:

• Ascorbic acid (AsA) is a crucial antioxidant in plants, and its recycling is vital for cellular protection.
• Dehydroascorbate reductase (DHAR) enzymes are key players in the AsA redox cycle, regenerating AsA from its oxidized form, dehydroascorbate (DHA).
• Understanding DHAR function is essential for improving plant stress tolerance.

Purpose:

• To isolate and characterize two novel dehydroascorbate reductase (DHAR) genes from common wheat (Triticum aestivum).
• To investigate the expression patterns, subcellular localization, and enzymatic activity of the identified wheat DHAR proteins (TaDHAR1 and TaDHAR2).
• To provide foundational data for future research on the role of wheat DHAR in ascorbic acid metabolism under various conditions.

Summary:

• Two full-length cDNA clones, TaDHAR1 and TaDHAR2, were successfully isolated from common wheat.
• Expression analysis revealed transcription in multiple vegetative and reproductive organs, with potential cytoplasmic localization of the protein products.
• Recombinant TaDHAR1 and TaDHAR2 proteins demonstrated dehydroascorbate reductase activity, with optimal function at 37°C and pH 7.5, offering insights into their biochemical properties.

Impact:

• The characterization of TaDHAR1 and TaDHAR2 provides valuable genetic resources for studying AsA metabolism in wheat.
• Findings contribute to understanding plant responses to normal and stressed environmental conditions.
• This research may facilitate the development of strategies to enhance crop resilience through improved antioxidant systems.