title: Overexpression of ferredoxin, PETF, enhances tolerance to heat stress in Chlamydomonas reinhardtii.
abstract: Reactive oxygen species (ROS) produced by plants in adverse environments can cause damage to organelles and trigger cell death. Removal of excess ROS can be achieved through the ascorbate scavenger pathway to prevent plant cell death. The amount of this scavenger can be regulated by ferredoxin (FDX). Chloroplastic FDXs are electron transfer proteins that perform in distributing photosynthetic reducing power. In this study, we demonstrate that overexpression of the endogenous photosynthetic FDX gene, PETF, in Chlamydomonas reinhardtii could raise the level of reduced ascorbate and diminish H2O2 levels under normal growth conditions. Furthermore, the overexpressing PETF transgenic Chlamydomonas lines produced low levels of H2O2 and exhibited protective effects that were observed through decreased chlorophyll degradation and increased cell survival under heat-stress conditions. The findings of this study suggest that overexpression of PETF can increase the efficiency of ROS scavenging in chloroplasts to confer heat tolerance. The roles of PETF in the downregulation of the ROS level offer a method for potentially improving the tolerance of crops against heat stress.
authors.affiliation: Department of Plant Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan. hlf326@saturn.yzu.edu.tw.
authors.forename: Yi-Hsien
authors.initials: YH
authors.lastname: Lin
authors.forename: Kui-You
authors.initials: KY
authors.lastname: Pan
authors.forename: Ching-Hui
authors.initials: CH
authors.lastname: Hung
authors.forename: Hsiang-En
authors.initials: HE
authors.lastname: Huang
authors.forename: Ching-Lian
authors.initials: CL
authors.lastname: Chen
authors.forename: Teng-Yung
authors.initials: TY
authors.lastname: Feng
authors.forename: Li-Fen
authors.initials: LF
authors.lastname: Huang
mesh_terms: D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D002734:Chlorophyll / Q000235:genetics; D005288:Ferredoxins / Q000235:genetics*; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology*
chemical_list: D005288:Ferredoxins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D002734:Chlorophyll; D006861:Hydrogen Peroxide