Regulation of protein import into chloroplast
Correct and efficient targeting and translocation of the precursor proteins synthesized in the nucleus is vital for the chloroplast function. Two-hybrid yeast system was employed to investigate the factors involved in the regulation of preSSU (precursor of small subunit of Ribisco) during its import processes from nucleus into chloroplast. Six kinds of candidate genes were found to be putative partners of preSSU. They are the candidate histidine protein kinase genes, the translocation protein genes and complex, the transcriptional and translocation related genes and proteins, plant defensin protein and EREB transcriptional factors and the photosynthesis related genes, respectively. The preSSU probably participates in different processes involved in plant response to stress and pathogen infection, and plays an important role in plant growth, ripening and senescence.