The Multiple Roles of Ascorbate in the Abiotic Stress Response of Plants: Antioxidant, Cofactor, and Regulator

Abstract

Ascorbate (ASC) plays a critical role in plant stress response. The antioxidant role of ASC has been well-studied, but there are still several confusing questions about the function of ASC in plant abiotic stress response. ASC can scavenge reactive oxygen species (ROS) and should be helpful for plant stress tolerance. But in some cases, increasing ASC content impairs plant abiotic stress tolerance, whereas, inhibiting ASC synthesis or regeneration enhances plant stress tolerance. This confusing phenomenon indicates that ASC may have multiple roles in plant abiotic stress response not just as an antioxidant, though many studies more or less ignored other roles of ASC in plant. In fact, ACS also can act as the cofactor of some enzymes, which are involved in the synthesis, metabolism, and modification of a variety of substances, which has important effects on plant stress response. In addition, ASC can monitor and effectively regulate cell redox status. Therefore, we believe that ASC has atleast triple roles in plant abiotic stress response: as the antioxidant to scavenge accumulated ROS, as the cofactor to involve in plant metabolism, or as the regulator to coordinate the actions of various signal pathways under abiotic stress. The role of ASC in plant abiotic stress response is important and complex. The detail role of ASC in plant abiotic stress response should be analyzed according to specific physiological process in specific organ. In this review, we discuss the versatile roles of ASC in the response of plants to abiotic stresses.

How to Cope with the Challenges of Environmental Stresses in the Era of Global Climate Change: An Update on ROS Stave off in Plants

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“…An increase in the levels of cellular α-tocopherol (vitamin E) has been found in response to high light and osmotic stress tolerance in tobacco [206]. Similarly, tocopherols and tocotrienols are other key components of the cellular membrane that play a crucial role in the antioxidant system [166,207].…”

A Transcriptional Analysis of the Genes Involved in the Ascorbic Acid Pathways Based on a Comparison of the Juice and Leaves of Navel and Anthocyanin-Rich Sweet Orange Varieties

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Impact of Ascorbate—Glutathione Cycle Components on the Effectiveness of Embryogenesis Induction in Isolated Microspore Cultures of Barley and Triticale

“…It is also involved in apical meristem formation, development of root architecture, regulation of flowering time and leaf senescence. Recent reports also postulated its participation in epigenetic regulation (review in [11]).…”