Disruption of the psbA gene by the copy correction mechanism reveals that the expression of plastid-encoded genes is regulated by photosynthesis activity
| Autor: | Waqar Hameed, Muhammad Sarwar Khan, Mikio Nozoe, Takashi Shiina |
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| Rok vydání: | 2007 |
| Předmět: |
Chloroplasts
Transcription Genetic Plant Science Biology Genes Plant Polymerase Chain Reaction Genome chemistry.chemical_compound RNA polymerase Tobacco Plastids Photosynthesis Plastid Gene DNA Primers Sequence Deletion Genetics fungi Photosystem II Protein Complex food and beverages Plants Genetically Modified Phenotype Reverse genetics Heteroplasmy Chloroplast chemistry Mutagenesis Gene Deletion Genome Plant |
| Zdroj: | Journal of Plant Research. 120:421-430 |
| ISSN: | 1618-0860 0918-9440 |
| DOI: | 10.1007/s10265-007-0082-3 |
| Popis: | The functional analysis of genes encoded by the chloroplast genome of tobacco by reverse genetics is routine. Nevertheless, for a small number of genes their deletion generates heteroplasmic genotypes, complicating their analysis. There is thus the need for additional strategies to develop deletion mutants for these genes. We have developed a homologous copy correction-based strategy for deleting/mutating genes encoded on the chloroplast genome. This system was used to produce psbA knockouts. The resulting plants are homoplasmic and lack photosystem II (PSII) activity. Further, the deletion mutants exhibit a distinct phenotype; young leaves are green, whereas older leaves are bleached, irrespective of light conditions. This suggests that senescence is promoted by the absence of psbA. Analysis of the transcript levels indicates that NEP (nuclear-encoded plastid RNA polymerase)-dependent plastid genes are up regulated in the psbA deletion mutants, whereas the bleached leaves retain plastid-encoded plastid RNA polymerase activity. Hence, the expression of NEP-dependent plastid genes may be regulated by photosynthesis, either directly or indirectly. |
| Databáze: | OpenAIRE |
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