Tottori University

In light of the fact that climate change has emerged as one of the difficulties confronting the global food system, researchers are obligated to work toward developing fundamental crops, particularly wheat, to combat environmental stress, including drought and salt. In the present study, genetic engineering was used to transfer the Arabidopsis MDAR1 gene, which controls the buildup of ascorbic acid (AsA) to make bread wheat less likely to be sensitive to salt stress. The biolistic bombardment was used to transfer cDNA from the Arabidopsis thaliana plant that encodes MDAR1 into Bobwhite 56 cultivar wheat plants. A molecular investigation was performed on six different transgenic lines to confirm the integration of the transgene, the copy number, and the expression of the transgene. There were one to three copies of the transgene, and there was no association found between the number of copies of the transgene and All the data generated or analyzed during this study are included in this published article [and its supplementary information files].the presence of its expression. Compared to plants that were not transgenic, the amount of ascorbic acid (AsA) that accumulated in the transgenic plants was twice as high. ROS concentrations are significantly lower in transgenic plants compared to non-transgenic plants under both control and salt stress conditions, effectively reducing oxidative stress. By cultivating transgenic T2 plants in a greenhouse, we were able to determine whether they were able to tolerate the potentially damaging effects of salt stress (200 mm). The study concluded that transgenic wheat plants that consistently expressed the MDAR1 gene become tolerant to salt stress with improvement in growth characteristics.

Hybrid breeding has emerged as a pivotal strategy to enhance wheat crop yield, a critical step to meet the escalating food demand for the growing global population. Heterosis in wheat can boost crop yield; however, harnessing heterosis in bread wheat is complex and hindered by the species' inherent tendency for self-pollination, high genome ploidy, and limitation of male sterile lines. In contrast, the availability of genetic male sterility, and altering reproductive biology such as anther extrusion and floret opening, is challenging but could facilitate outcrossing. Despite the advancements in sterility systems and molecular tools, an efficient and environmentally stable wheat hybrid production system is still lacking. In this review, we examine the advantages and limitations of different male sterility sources utilized to date including, chemical hybridizing agents (CHAs), cytoplasmic male sterility (CMS), nuclear genic male sterility (NGMS), and environmental-sensitive male sterility (ESMS). Furthermore, we explore the potential of molecular tools such as marker-assisted selection (MAS), genome editing, and other genetic engineering approaches to accelerate hybrid wheat breeding efforts. Future research directions are proposed to develop robust, cost-effective systems by integrating conventional and molecular approaches with advanced screening methods including cytogenomics and next generation sequencing (NGS), which can reliably help to produce stable, high-yielding, and resilient hybrid wheat cultivars compared to current open-pollinated varieties. Collectively, these efforts are vital to achieve the food demands for escalating population under climate change scenario.

Ascorbate is a key antioxidant that protects plant cells from oxidative damage. While plants actively synthesize ascorbate during the day, its degradation becomes prominent under prolonged dark conditions. Since ascorbate degradation begins with its oxidized form, dehydroascorbate (DHA), this process inherently requires ascorbate oxidation. However, the molecular mechanisms underlying dark-induced ascorbate oxidation and subsequent degradation remain unclear. In this study, we investigated the role of intracellular and extracellular ascorbate redox regulation in controlling this process. Using Arabidopsis knockout mutants for key enzymes involved in ascorbate oxidation and recycling, including ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR), and ascorbate oxidase (AO), as well as NADPH oxidases (rbohD and rbohF), we found that none of these enzymes significantly influenced the dark-induced decrease in ascorbate levels. Notably, ascorbate levels decreased similarly in newly generated multiple mutants, including a quintuple mutant (∆dhar pad2 mdar5), which has severely impaired ascorbate recycling capacity, and the ao2 rbohD double mutant, which is strongly expected to exhibit a highly altered apoplastic redox state. Furthermore, we examined the potential involvement of senescence signaling, including ORESARA1 and ethylene signaling components, but found no evidence for their contribution. These findings indicate that the dark-induced decrease in ascorbate levels is not governed by conventional pathways for ascorbate oxidation and recycling or senescence signaling processes, suggesting an unidentified regulatory mechanism.