title: In Vivo Assessment of Cold Tolerance through Chlorophyll-a Fluorescence in Transgenic Zoysiagrass Expressing Mutant Phytochrome A.
abstract: Chlorophyll-a fluorescence analysis provides relevant information about the physiology of plants growing under abiotic stress. In this study, we evaluated the influence of cold stress on the photosynthetic machinery of transgenic turfgrass, Zoysia japonica, expressing oat phytochrome A (PhyA) or a hyperactive mutant phytochrome A (S599A) with post-translational phosphorylation blocked. Biochemical analysis of zoysiagrass subjected to cold stress revealed reduced levels of hydrogen peroxide, increased proline accumulation, and enhanced specific activities of antioxidant enzymes compared to those of control plants. Detailed analyses of the chlorophyll-a fluorescence data through the so-called OJIP test exhibited a marked difference in the physiological status among transgenic and control plants. Overall, these findings suggest an enhanced level of cold tolerance in S599A zoysiagrass cultivars as reflected in the biochemical and physiological analyses. Further, we propose that chlorophyll-a fluorescence analysis using OJIP test is an efficient tool in determining the physiological status of plants under cold stress conditions.
authors.affiliation: Subtropical Horticulture Research Institute, Faculty of Biotechnology, Jeju National University, Jeju 690-756, South Korea; School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbook 712-749, South Korea.
authors.forename: Mayank Anand
authors.initials: MA
authors.lastname: Gururani
authors.affiliation: Department of Molecular Biotechnology, Konkuk University, Seoul 143-701, South Korea.
authors.forename: Jelli
authors.initials: J
authors.lastname: Venkatesh
authors.affiliation: Subtropical Horticulture Research Institute, Faculty of Biotechnology, Jeju National University, Jeju 690-756, South Korea; Department of Biological Sciences, Presidency University, Kolkata 700073, West Bengal, India.
authors.forename: Markkandan
authors.initials: M
authors.lastname: Ganesan
authors.affiliation: Bioenergetics Laboratory, University of Geneva, Jussy, CH-1254, Geneva, Switzerland.
authors.forename: Reto Jörg
authors.initials: RJ
authors.lastname: Strasser
authors.affiliation: Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Yunjeong
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Biotechnology and Kumho Life Science Laboratory, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Jeong-Il
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Subtropical Horticulture Research Institute, Faculty of Biotechnology, Jeju National University, Jeju 690-756, South Korea.
authors.forename: Hyo-Yeon
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Subtropical Horticulture Research Institute, Faculty of Biotechnology, Jeju National University, Jeju 690-756, South Korea.
authors.forename: Pill-Soon
authors.initials: PS
authors.lastname: Song
mesh_terms: D019943:Amino Acid Substitution; D002734:Chlorophyll / Q000235:genetics / Q000378:metabolism*; D000077194:Chlorophyll A; D003080:Cold Temperature; D058639:Cold-Shock Response / Q000502:physiology*; D005453:Fluorescence; D020125:Mutation, Missense; D051942:Phytochrome A / Q000096:biosynthesis* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D006109:Poaceae / Q000235:genetics / Q000378:metabolism*
chemical_list: D051942:Phytochrome A; D002734:Chlorophyll; D000077194:Chlorophyll A