Redox Regulation of the NOR Transcription Factor Is Involved in the Regulation of Fruit Ripening in Tomato. Issue 2 (31st March 2020)

• Record Type: Journal Article
• Authors: Jiang, Guoxiang; Zeng, Jing; Li, Zhiwei; Song, Yunbo; Yan, Huiling; He, Junxian; Jiang, Yueming; Duan, Xuewu
• Is Part Of: Plant physiology. Volume 183:Issue 2(2020)
• Page Start: 671
• Page End: 685
• Publication Date: 2020-03-31
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.20.00070
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Sulfoxidation of NON-RIPENING transcription factor regulates tomato fruit ripening by decreasing its DNA binding capacity and transcriptional regulatory activity. Abstract: Transcription factors (TFs) are important regulators of plant growth and development and responses to stresses. TFs themselves are also prone to multiple posttranslational modifications (PTMs). However, redox-mediated PTM of TFs in plants remains poorly understood. Here, we established that NON-RIPENING (NOR), a master TF regulating tomato ( Solanum lycopersicum ) fruit ripening, is a target of the Met sulfoxide reductases A and B, namely E4 and SlMsrB2, respectively, in tomato. Met oxidation in NOR, i.e. sulfoxidation, or mimicking sulfoxidation by mutating Met-138 to Gln, reduces its DNA-binding capacity and transcriptional regulatory activity in vitro. E4 and SlMsrB2 partially repair oxidized NOR and restore its DNA-binding capacity. Transgenic complementation of the nor mutant with NOR partially rescues the ripening defects. However, transformation of nor with NOR-M138Q, containing mimicked Met sulfoxidation, inhibits restoration of the fruit ripening phenotype, and this is associated with the decreased DNA-binding and transcriptional activation of a number of ripening-related genes. Taken together, these observations reveal a PTM mechanism by which Msr-mediated redox modification of NOR regulates the expression of ripening-related genes, thereby influencing tomato fruit ripening. Our report describes how sulfoxidation of TFs regulates developmental processes in plants.