Project description:In the present study we investigated at the system level the proteome obtained from seedlings of Arabidopsis thaliana wild-type Col-0 and gun1-101 and gun1-102 mutant plants treated or not with lincomycin (Lin), a chloroplast translation inhibitor widely used to inhibit chloroplast biogenesis and to trigger the plastid-to-nucleus retrograde communication. Specifically, we attempted a description of cellular responses to Lincomycin in wild-type genetic background and in retrograde signaling-defective mutant gun1. Hypotheses and key players emerged by our holistic view were validated at the experimental level. Our findings suggest that, in the presence of Lincomycin, cell responses rely on the plastid compartment in a GUN1-dependent manner, while in the gun1-mutant background, the activity of extra-plastid compartments prevails. Moreover, results obtained by complementary approaches depict the Oxygen Evolving Complex subunit PsbO as an atypical Photosynthesis-related protein by accumulating in non-photosynthetic plastids and having a superhub role in modulating chloroplast dismantling upon impairment of plastid functions.
Project description:The role of abscisic acid (ABA) signalling in the ascorbic acid (AA)-dependent control of plant growth and defence was determined using the vtc1 and vtc2 mutants, which have impaired ascorbic acid synthesis, and in the abi4 mutant that is impaired in ABA-signalling. ABA levels were increase in the mutants relative to the wild type (Col0). Like vtc1 the vtc2 mutants have a slow growth relative to Col0. However, the wild type phenotype is restored in the abi4vtc2 double mutant. Similarly, the sugar sensing phenotype of in the abi4 is reversed in the abi4vtc2 double mutant. The vtc1 and vtc2 leaf transcriptomes show up to 70 % homology with abi4. Of the transcripts that are altered in the mutants a relative to Col0, only a small number are reversed in the abi4vtc2 double mutants relative to either abi4 or vtc2. We conclude that AA controls growth via an ABA and abi4-dependent signalling pathway. The vtc and abi4 mutants have enhanced glutathione levels and common redox signalling pathways leading to similar gene expression patterns.
Project description:The role of abscisic acid (ABA) signalling in the ascorbic acid (AA)-dependent control of plant growth and defence was determined using the vtc1 and vtc2 mutants, which have impaired ascorbic acid synthesis, and in the abi4 mutant that is impaired in ABA-signalling. ABA levels were increase in the mutants relative to the wild type (Col0). Like vtc1 the vtc2 mutants have a slow growth relative to Col0. However, the wild type phenotype is restored in the abi4vtc2 double mutant. Similarly, the sugar sensing phenotype of in the abi4 is reversed in the abi4vtc2 double mutant. The vtc1 and vtc2 leaf transcriptomes show up to 70 % homology with abi4. Of the transcripts that are altered in the mutants a relative to Col0, only a small number are reversed in the abi4vtc2 double mutants relative to either abi4 or vtc2. We conclude that AA controls growth via an ABA and abi4-dependent signalling pathway. The vtc and abi4 mutants have enhanced glutathione levels and common redox signalling pathways leading to similar gene expression patterns.
Project description:This SuperSeries is composed of the following subset Series: GSE23329: Transcriptome analysis of vtc2, abi4-102 and the corresponding double mutant abi4 vtc2 GSE23330: Transcriptome analysis of vtc1, abi4-102 and wild type Col 0 Refer to individual Series
Project description:GUN1 proteins controls protein homeostasis in chloroplast development in cotyledons of the model plant Arabidopsis thaliana, via coordination of nuclear encoded polymerase (NEP)-dependent chloroplast genes expression with plastid encoded polymerase (PEP)-dependent chloroplast genes expression. Lack of GUN1 leads to development of abnormal plastids and, consequently, accumulation of nuclear-encoded chloroplast-targeted (NECT) proteins which in many cases have been found still in their precursor form. Data dependent acquisition (DDA) mass spectrometry analysis of cotyledons soluble fractions, as well as targeted proteomics analysis of specific FtsH protease forms recognized by FtsH antibodies in western blotting, have been performed to identify peptides from the chloroplast transit peptide (cTP) of NECT in cotyledons extracts of wild type and GUN1 knocked-out mutant plants. The aim was to compare the number of cTPs found in 6 days after sowing (DAS) seedlings grown on plates with or without the inhibitor of plastid translation lincomycin.
Project description:The role of abscisic acid (ABA) signalling in the ascorbic acid (AA)-dependent control of plant growth and defence was determined using the vtc1 and vtc2 mutants, which have impaired ascorbic acid synthesis, and in the abi4 mutant that is impaired in ABA-signalling. ABA levels were increase in the mutants relative to the wild type (Col0). Like vtc1 the vtc2 mutants have a slow growth relative to Col0. However, the wild type phenotype is restored in the abi4vtc2 double mutant. Similarly, the sugar sensing phenotype of in the abi4 is reversed in the abi4vtc2 double mutant. The vtc1 and vtc2 leaf transcriptomes show up to 70 % homology with abi4. Of the transcripts that are altered in the mutants a relative to Col0, only a small number are reversed in the abi4vtc2 double mutants relative to either abi4 or vtc2. We conclude that AA controls growth via an ABA and abi4-dependent signalling pathway. The vtc and abi4 mutants have enhanced glutathione levels and common redox signalling pathways leading to similar gene expression patterns. Rosettes of 42 days old plants were harvested and used to exctract RNA