Loss-of-function mutation in SCY1 triggers chloroplast-to-nucleus retrograde signaling in Arabidopsis thaliana

• DOI: 10.1007/s10535-015-0514-1
• Publication Date: 2015-04-28T18:14:16Z
• Authors: D. Liu; Z. M. Wu; L. Hou
• Keywords: Twin-arginine translocation pathway; Etiolation; Nuclear gene

The secretory (Sec) pathway is one of the most important systems for transporting proteins across thylakoid membrane into lumen. Two Arabidopsis genes encoding SecY translocon proteins, designated SCY1 and SCY2, were characterized in this study. Semi-quantitative RT-PCR histochemical staining β-glucuronidase (GUS) activity reveal that both SCY2 promoters active germinating seeds, etiolated cotyledons, flowers, but not roots. In particular, expression GUS gene driven by promoter was almost undetectable green leaves, whereas controlled clearly detected. Moreover, homozygous scy1-1 plants could grow heterotrophically appeared sensitive to radiation. Further studies show chloroplasts arrested early developmental stages with fewer membranes. Real-time quantitative reveals a number nuclear-encoded involved chlorophyll biosynthesis photosynthesis substantially down-regulated mutant. All these results indicate SCY1/2 regulated developmentally spatially, loss-of-function mutation triggered chloroplast-to-nucleus retrograde signaling thaliana.