tailieunhanh - báo cáo khoa học: " Small chloroplast-targeted DnaJ proteins are involved in optimization of photosynthetic reactions in Arabidopsis thaliana"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Small chloroplast-targeted DnaJ proteins are involved in optimization of photosynthetic reactions in Arabidopsis thaliana | Chen et al. BMC Plant Biology 2010 10 43 http 1471-2229 10 43 BMC Plant Biology RESEARCH ARTICLE Open Access Small chloroplast-targeted DnaJ proteins are involved in optimization of photosynthetic reactions in Arabidopsis thaliana 2 1 1 111 Kun-Ming Chen Maija Holmstrom Wuttinun Raksajit Marjaana Suorsa Mirva Piippo Eva-Mari Aro Abstract Background DnaJ proteins participate in many metabolic pathways through dynamic interactions with various components of these processes. The role of three small chloroplast-targeted DnaJ proteins AtJ8 At1 g80920 AtJ11 At4 g36040 and AtJ20 At4 g13830 was investigated here using knock-out mutants of Arabidopsis thaliana. Photochemical efficiency capacity of CO2 assimilation stabilization of Photosystem PS II dimers and supercomplexes under high light illumination energy distribution between PSI and PSII and phosphorylation of PSII-LHCII proteins global gene expression profiles and oxidative stress responses of these DnaJ mutants were analyzed. Results Knockout of one of these proteins caused a series of events including a decrease in photosynthetic efficiency destabilization of PSII complexes and loss of control for balancing the redox reactions in chloroplasts. Data obtained with DNA microarray analysis demonstrated that the lack of one of these DnaJ proteins triggers a global stress response and therefore confers the plants greater tolerance to oxidative stress induced by high light or methyl viologen treatments. Expression of a set of genes encoding enzymes that detoxify reactive oxygen species ROS as well as a number of stress-related transcription factors behaved in the mutants at growth light similarly to that when wild-type WT plants were transferred to high light. Also a set of genes related to redox regulation were upregulated in the mutants. On the other hand although the three DnaJ proteins reside in chloroplasts the expression of most genes encoding thylakoid membrane proteins was not changed in the