ABA-dependent K+ flux is one of the important features of the drought response that distinguishes Catalpa from two different habitats. (2nd April 2020)

• Record Type: Journal Article
• Authors: Ma, Wenjun; Yang, Guijuan; Xiao, Yao; Zhao, Xiyang; Wang, Junhui
• Is Part Of: Plant signaling & behavior. Volume 15:Number 4(2020)
• Publication Date: 2020-04-02
• Subjects: Abscisic acid -- Catalpa -- drought tolerance -- k+ efflux -- noninvasive micro-test technique -- PEG -- TEA -- SKOR; Plant ecophysiology -- Periodicals; Plant cellular signal transduction -- Periodicals; Plant cellular signal transduction; Plant ecophysiology; Periodicals; Electronic journals; 581
• DOI: 10.1080/15592324.2020.1735755
• Languages: English
• ISSNs: 1559-2316

Abstract

ABSTRACT: Abscisic acid (ABA)-induced stomatal closure can improve drought tolerance in higher plants. However, the relationship between ABA-related ion flux and improved drought resistance in the roots of woody plants is unclear. To investigate this relationship, we employed a noninvasive micro-test technique (NMT) to detect potassium (K + ) flux in Catalpa fargesii and C. fargesii f . duclouxii after treatment with polyethylene glycol (PEG) and ABA. PEG treatment slightly increased the free proline content in both Catalpa species. However, simultaneous treatment with ABA and PEG resulted in a large increase in free proline content. Treatment with PEG led to a significant increase in K + efflux, and both ABA and tetraethylammonium (TEA, a K + channel inhibitor) blocked this efflux under short-term (1 d) and long-term (7 d) drought conditions. Furthermore, we detected SKOR (stelar K + outward-rectifying channel) gene expression in roots, and the results showed that PEG significantly increased SKOR expression in C. fargesii f . duclouxii, but SKOR expression was inhibited by ABA in Catalpa fargesii . These findings indicate that ABA improves drought tolerance by inhibiting K + efflux in Catalpa, but distinct ABA response patterns exist. Drought-tolerant species have better potassium retention are dependent on ABA, and can accumulate more proline than other species. SKOR is also ABA-dependent and sensitive to ABA, and K + flux is a target of the ABA-mediated drought response.