Essential role for phytol kinase and tocopherol in tolerance to combined light and temperature stress in tomato. (24th November 2017)

• Record Type: Journal Article
• Authors: Spicher, Livia; Almeida, Juliana; Gutbrod, Katharina; Pipitone, Rosa; Dörmann, Peter; Glauser, Gaétan; Rossi, Magdalena; Kessler, Felix
• Is Part Of: Journal of experimental botany. Volume 68:Number 21/22(2017)
• Page Start: 5845
• Page End: 5856
• Publication Date: 2017-11-24
• Subjects: High-light stress -- high-temperature stress -- lipidomics -- phytol -- phytol kinase -- plastochromanol -- plastoglobules -- plastoquinone -- Solanum lycopersicum -- tocopherol; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/erx356
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : An essential role is identified for tocopherol in tomato under combined high-light and high-temperature stress. The dual antioxidant and membrane-stabilizing properties of tocopherol may explain its role in combined stress tolerance. Abstract: In a changing environment, plants need to cope with the impact of rising temperatures together with high light intensity. Here, we used lipidomics in the tomato model system to identify lipophilic molecules that enhance tolerance to combined high-temperature and high-light stress. Among several hundred metabolites, the two most strongly up-regulated compounds were α-tocopherol and plastoquinone/plastoquinol. Both are well-known lipid antioxidants and contribute to the protection of photosystem II (PSII) against photodamage under environmental stress. To address the protective function of tocopherol, an RNAi line ( vte5 ) with decreased expression of VTE5 and reduced levels of α-tocopherol was selected. VTE5 encodes phytol kinase, which acts in the biosynthetic pathway of tocopherols. vte5 suffered strong photoinhibition and photobleaching when exposed to combined high-light and high-temperature stress, but neither stress alone produced a visible phenotype. As vte5 had plastoquinone levels similar to those of the wild type under combined stress, the strong phenotype could be attributed to the lack of α-tocopherol. These findings suggest that VTE5 protects against combined high-light and high-temperature stress and does so by supporting α-tocopherol production.