PROGRAMMED CELL DEATH8 interacts with tetrapyrrole biosynthesis enzymes and ClpC1 to maintain homeostasis of tetrapyrrole metabolites in Arabidopsis

• DOI: 10.1111/nph.18906
• Publication Date: 2023-03-27T05:48:49Z
• Authors: Rudan Geng; Xiaoqing Pang; Xia Li; Shanshan Shi; Boris Hedtke; Bernhard Grimm; Ralph Bock; Jirong Huang; Wenbin Zhou
• Keywords: Tetrapyrrole; Retrograde signaling; Ferrochelatase; Genetic screen

Tetrapyrrole biosynthesis (TBS) is a dynamically and strictly regulated process. Disruptions in tetrapyrrole metabolism influence many aspects of plant physiology, including photosynthesis, programmed cell death (PCD), retrograde signaling, thus affecting growth development at multiple levels. However, the genetic molecular basis TBS not fully understood. We report here PCD8, newly identified thylakoid-localized protein encoded by an essential gene Arabidopsis. PCD8 knockdown causes necrotic phenotype due to excessive chloroplast damage. A burst singlet oxygen that results from overaccumulated intermediates upon illumination suggested be responsible for mutants. Genetic biochemical analyses revealed interacts with ClpC1 number enzymes, such as HEMC, CHLD, PORC TBS. Taken together, our findings uncover function chloroplast-localized provide new perspective elucidate mechanism how finely plants.