Exogenous Sulfide Reverses the Alteration of Transcriptional Profiling of the des1-1 Mutant (Arabidopsis thaliana)

ABSTRACT: Arabidopsis thaliana cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes that catalyze the biosynthesis of cysteine. Recently, we have deeply investigated about one of the minor OASTL-like protein located in the cytosol, named DES1, highlighting some important clues about its metabolic function. We have demonstrated that DES1 catalyzes the desulfuration of L-cysteine to sulfide plus ammonia and pyruvate, instead of the biosynthesis of Cys, and thus, is a novel L-cysteine desulfhydrase (EC 4.4.1.1). The functionality of DES1 is being revealed by the phenotype of the T-DNA insertion mutants des1-1 and des1-2. We have performed a comparative transcriptomic analysis on leaves of the des1-1 and Col-0 wild type plants grown for 30 days under long-day conditions. The normalized data from the replicates showed differential expression of 1614 genes in the des1-1 mutant, with 701 genes down-regulated and 913 genes up-regulated by more than twofold, with a False Discovery Rate (FDR) of < 0.05 and an intensity signal restriction of lgSignal >7. This des1-1 transcriptional profile show a strong alteration when compared to a previous comparative transcriptomic analysis performed on leaves of the des1-1 and Col-0 wild type plants grown for 20 days under identical long-day conditions (GSE 19244). We have also performed a comparative transcriptomic analysis on leaves of the des1-1 and Col-0 wild type plants grown for 20 days and treated with sodium sulfide for 10 additional days. The comparison of the transcriptional profile of des1-1+Na2S versus Col-0+Na2S clearly shows that exogenous sulfide reversed the transcriptional level differences between the mutant and the wild type to reach similar transcriptional patterns as the array GSE19244. Our results suggest a role of sulfide as transcriptional regulator in the des1-1 mutant background. Using the Affymetrix ATH1 GeneChips, we performed two comparative transcriptomic analyses on leaves of the des1-1 and Col-0 wild type plants grown on soil under long-day conditions. One was performed on plants grown for 30 days and the other on plants grown for 20 days and treated for 10 additional days with 200 mM Na2S. Three biological replicates were performed for each sample and hybridized to the chips. We made the comparison of des1-1 versus wild-type and des1-1+Na2S versus wild-type+Na2S to classify the differently expressed genes in the mutant plant.

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Cecilia Gotor 

PROVIDER: E-GEOD-32566 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress