Virus induced PhFTRv gene silencing results in yellow-green leaves and reduced cold tolerance in petunia

Ferredoxin-thioredoxin reductase (FTR) is an iron-sulfur protein that supplies electrons from photochemically reduced ferredoxin (Fd) to thioredoxin (Trx) in the ferredoxin/thioredoxin system in chloroplasts. The FTR is a heterodimer with a variable subunit (FTRv) and a catalytic subunit (FTRc). The function of FTRv is not well known. In petunia (Petunia hybrida), FTRv is a single-copy gene, which is named PhFTRv. In this study, the spatio-temporal expression of PhFTRv in petunia was analyzed, and PhFTRv transcription was found to be high in leaves and stems. A tobacco rattle virus gene silencing was used in this study. Virus induced gene silencing-mediated PhFTRv silencing resulted in large yellow-green leaves, delayed flowering, and reduced cold tolerance in petunia plants. Additional key words: flowering, chloroplasts, chlorophyll, leaf development, Petunia hybrida, photosynthesis, temperature stress. Submitted 28 June 2020, last revision 27 September 2020, accepted 12 October 2020. Abbreviations: ci internal CO2 concentration; Fd ferredoxin; FTR ferredoxin-thioredoxin reductase; gs stomatal conductance; NTRC NADPH-dependent thioredoxin reductase C; PN net photosynthetic rate; TRV tobacco rattle virus; Trx thioredoxin; VIGS virus induced gene silencing. Acknowledgements: This research was supported by the National Natural Science Foundation of China (31770737, 31870692 and 31661143047) and the National Key Research and Development Plan (2018YFD100015). * Corresponding author; e-mail: juanxuliu@scau.edu.cn This is an open access article distributed under the terms of the Creative Commons BY-NC-ND Licence