tailieunhanh - báo cáo khoa học: " A var2 leaf variegation suppressor locus, SUPPRESSOR OF VARIEGATION3, encodes a putative chloroplast translation elongation factor that is important for chloroplast development in the cold"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: A var2 leaf variegation suppressor locus, SUPPRESSOR OF VARIEGATION3, encodes a putative chloroplast translation elongation factor that is important for chloroplast development in the cold | Liu et al. BMC Plant Biology 2010 10 287 http 1471-2229 10 287 BMC Plant Biology RESEARCH ARTICLE Open Access A var2 leaf variegation suppressor locus SUPPRESSOR OF VARIEGATION3 encodes a putative chloroplast translation elongation factor that is important for chloroplast development in the cold Xiayan Liu 1 Steve R Rodermel2 Fei Yu1 Abstract Background The Arabidopsis var2 mutant displays a unique green and white yellow leaf variegation phenotype and lacks VAR2 a chloroplast FtsH metalloprotease. We are characterizing second-site var2 genetic suppressors as means to better understand VAR2 function and to study the regulation of chloroplast biogenesis. Results In this report we show that the suppression of var2 variegation in suppressor line TAG-11 is due to the disruption of the SUPPRESSOR OF VARIEGATIONS SVR3 gene encoding a putative TypA-like translation elongation factor. SVR3 is targeted to the chloroplast and svrS single mutants have uniformly pale green leaves at 22 C. Consistent with this phenotype most chloroplast proteins and rRNA species in svrS have close to normal accumulation profiles with the notable exception of the Photosystem II reaction center D1 protein which is present at greatly reduced levels. When svrS is challenged with chilling temperature 8 C it develops a pronounced chlorosis that is accompanied by abnormal chloroplast rRNA processing and chloroplast protein accumulation. Double mutant analysis indicates a possible synergistic interaction between svrS and svr7 which is defective in a chloroplast pentatricopeptide repeat PPR protein. Conclusions Our findings on one hand reinforce the strong genetic link between VAR2 and chloroplast translation and on the other hand point to a critical role of SVR3 and possibly some aspects of chloroplast translation in the response of plants to chilling stress. Background The photosynthetic apparatus of photosynthetic eukaryotic cells is the product of two genetic systems - the .