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S1 domain‐containing STF modulates plastid transcription and chloroplast biogenesis in Nicotiana benthamiana
Author(s) -
Jeon Young,
Jung Hyun Ju,
Kang Hunseung,
Park YounIl,
Lee Soon Hee,
Pai HyunSook
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2011.03941.x
Subject(s) - biology , plastid , nicotiana benthamiana , transcription (linguistics) , microbiology and biotechnology , chloroplast , gene , genetics , linguistics , philosophy
Summary• In this study, we examined the biochemical and physiological functions of Nicotiana benthamiana S1 domain‐containing Transcription‐Stimulating Factor (STF) using virus‐induced gene silencing (VIGS), cosuppression, and overexpression strategies. • STF : green fluorescent protein (GFP) fusion protein colocalized with sulfite reductase (SiR), a chloroplast nucleoid‐associated protein also present in the stroma. Full‐length STF and its S1 domain preferentially bound to RNA, probably in a sequence‐nonspecific manner. • STF silencing by VIGS or cosuppression resulted in severe leaf yellowing caused by disrupted chloroplast development. STF deficiency significantly perturbed plastid‐encoded multimeric RNA polymerase (PEP)‐dependent transcript accumulation. Chloroplast transcription run‐on assays revealed that the transcription rate of PEP‐dependent plastid genes was reduced in the STF ‐silenced leaves. Conversely, the exogenously added recombinant STF protein increased the transcription rate, suggesting a direct role of STF in plastid transcription. Etiolated seedlings of STF cosuppression lines showed defects in the light‐triggered transition from etioplasts to chloroplasts, accompanied by reduced light‐induced expression of plastid‐encoded genes. • These results suggest that STF plays a critical role as an auxiliary factor of the PEP transcription complex in the regulation of plastid transcription and chloroplast biogenesis in higher plants.