Fluorescence in blue light (FLU) is involved in inactivation and localization of glutamyl‐tRNA reductase during light exposure

• DOI: 10.1111/tpj.14138
• Publication Date: 2018-10-26T11:50:23Z
• Authors: Zhiwei Hou; Yanyu Yang; Boris Hedtke; Bernhard Grimm
• Keywords: Chlorophyll; 0303 health sciences; Light; Arabidopsis Proteins; Arabidopsis; Aminolevulinic Acid; Intracellular Membranes; Plants, Genetically Modified; Aldehyde Oxidoreductases; Fluorescence; Plant Leaves; Protein Transport; 03 medical and health sciences; Gene Expression Regulation, Plant; Seedlings; Plastids

Summary Fluorescent in blue light (FLU) is a negative regulator involved dark repression of 5‐aminolevulinic acid (ALA) synthesis and interacts with glutamyl‐tRNA reductase (GluTR), the rate‐limiting enzyme tetrapyrrole biosynthesis. In this study, we investigated FLU‘s regulatory function light‐exposed FLU‐overexpressing (FLUOE) Arabidopsis lines under fluctuating intensities wild‐type (WT) flu seedlings. FLUOE suppress ALA light, resulting reduced chlorophyll content, but more strongly low high than medium growth light. This situation indicates that FLU's impact on biosynthesis depends intensity. FLU overexpressors contain increased amounts mainly membrane‐associated GluTR. These findings correlate FLU‐dependent localization GluTR to plastidic membranes concomitant inhibition, such only soluble fraction active. The overaccumulation binding enhances stability. Interestingly, leaves mutants less compared WT become necrotic. We propose basically required for fine‐tuned synthesis. not mediates synthesis, functions also control balanced variable ensure adequate supply chlorophyll.