FITNESS, a CCT domain‐containing protein, deregulates reactive oxygen species levels and leads to fine‐tuning trade‐offs between reproductive success and defence responses in Arabidopsis

• Published in: Plant, cell and environment cell and environment, 2018-10, Vol.41 (10), p.2328-2341
• Main Authors: Osella, Ana Virginia, Mengarelli, Diego Alberto, Mateos, Julieta, Dong, Shuchao, Yanovsky, Marcelo J., Balazadeh, Salma, Valle, Estela Marta, Zanor, María Inés
• Format: Article
• Language: English
• Subjects: Animal reproduction; Arabidopsis - genetics; Arabidopsis - immunology; Arabidopsis - metabolism; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis Proteins - physiology; Breeding success; cell death; Chlorophyll - metabolism; Chloroplasts; Deregulation; Detoxification; Environmental stress; Fitness; flowering time; Gas Chromatography-Mass Spectrometry; Gene expression; Gene Expression Profiling; Homeostasis; Hydrogen peroxide; metabolism; Metabolites; Metabolomics; Mutants; Oxidative stress; photorespiration; Phylogeny; Plant Immunity; Plants, Genetically Modified; Polymerase Chain Reaction; Proline - metabolism; Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; Reproduction; Reproductive fitness; Salicylic acid; seed yield; Signal Transduction; Tuning
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.13354

Environmental stresses are the major factors that limit productivity in plants. Here, we report on the function of an uncharacterized gene At1g07050, encoding a CCT domain‐containing protein, from Arabidopsis thaliana. At1g07050 expression is highly repressed by oxidative stress. We used metabolomics, biochemical, and genomic approaches to analyse performance of transgenic lines with altered expression of At1g07050 under normal and oxidative stress conditions. At1g07050 overexpressing lines showed increased levels of reactive oxygen species (ROS), whereas knock‐out mutants exhibited decreased levels of ROS and higher tolerance to oxidative stress generated in the chloroplast. Our results uncover a role for At1g07050 in cellular redox homeostasis controlling H2O2 levels, due to changes in enzymes, metabolites, and transcripts related to ROS detoxification. Therefore, we call this gene FITNESS. Additionally, several genes such as ACD6, PCC1, and ICS1 related to salicylic acid signalling and defence were found differentially expressed among the lines. Notably, FITNESS absence significantly improved seed yield suggesting an effective fine‐tuning trade‐off between reproductive success and defence responses. Adverse environmental conditions induce cell oxidative stress in plants due to the generation of reactive oxygen species. Plants trigger the early expression of abiotic stress responses genes and down‐regulate the expression of few genes most of them encoding proteins with unknown functions. Here, we report about the role of one of these uncharacterized genes At1g07050, encoding a protein with a single CCT domain. The results suggest that At1g07050 acts as a link between stress‐activated responses and developmental programs, suggesting an effective fine‐tuning between reproductive success and defence, and therefore we called this gene FITNESS.