Chinese Bulletin of Botany ›› 2019, Vol. 54 ›› Issue (1): 119-132.DOI: 10.11983/CBB18047

• SPECIAL TOPICS • Previous Articles     Next Articles

Regulatory Mechanism of Thioredoxin (Trx) in Chloroplasts

Tong Qin1,2,Zhen Huang2,*(),Zhenhui Kang1,*()   

  1. 1 College of Bioengineering, Sichuan University of Science & Engineering, Zigong 643000, China;
    2 Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China
  • Received:2018-02-17 Accepted:2018-05-23 Online:2019-01-30 Published:2019-07-31
  • Contact: Zhen Huang,Zhenhui Kang

Abstract: Thioredoxins (Trx), a family of thiol-disulfide oxidoreductases, function as protein disulfide reductases to disulfide isomerases or to disulfide transferases to regulate the structure and function of intracellular proteins by modifying disulfide bonds between two cysteine residues in the side chain of the substrate proteins. The chloroplast Trx systems includes Trx and Trx-like proteins, ferredoxin (Fd)-dependent thioredoxin reductase (FTR) and reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent thioredoxin C (NADPH Trx reductase C, NTRC). In addition to regulating the activity of stromal enzymes and transportation of chloroplast proteins by the Trx system, the chloroplast contains a reduction potential transfer pathway across the thylakoid membrane. The reduction potential of the substrate Trx is mediated by the transmembrane transporter and finally to the thylakoid lumenal protein. FTR and NTRC coordinate to regulate chloroplast homeostasis. This paper summarizes the regulatory mechanism of the chloroplast thioredoxin system that highlights the significance of the chloroplast Trx system in maintaining photosynthetic efficiency in plants.

Key words: chloroplast, disulfide, photosynthetic efficiency, redox, thioredoxin