Project description:To further investigate how HID2 regulates translation during drought responses, we performed a comparative leaf proteome analysis using 24-day-old hid2 mutant and WT plants grown under well-watered and drought stress conditions.
Project description:Plants in temperate regions have evolved mechanisms to survive sudden temperature drops. Previous reports have indicated that the cold acclimation mechanism is light-dependent and does not fully operate under a low light intensity. In these studies, plants were grown under a long-day photoperiod and were more sensitive to freezing stress. However, winter annuals like Arabidopsis thaliana Col-0 germinate in the fall, overwinter as rosettes, and therefore must acclimate under short photoperiods and low irradiance. The role of light intensity was analysed in plants grown under a short-day photoperiod at the growth stage 1.14. Plants were acclimated at 4 °C for seven days under 100 and 20 μmol m-2s-1 PPFD for control and limited-light conditions, respectively. All cold acclimated plants accumulated molecular markers reportedly associated with acquired freezing tolerance, including proline, sucrose, CBFs, and COR gene protein products dehydrins and low-temperature-responsive proteins LTIs. Observed changes indicated that low PPFD did not inhibit the cold acclimation process, and the freezing stress experiment confirmed similar survival rates. The molecular analysis found distinct PPFD-specific adaptation mechanisms that were manifested in contrasting content of anthocyanins, cytokinin conjugates, abundances of proteins forming photosystems, and enzymes of protein, energy, and ROS metabolism pathways. Finally, this study led to the identification of putative proteins and metabolite markers correlating with susceptibility to freezing stress of non-acclimated plants grown under low PPFD. Our data show that Arabidopsis plants grown under short-day photoperiod can be fully cold-acclimated under limited light conditions, employing standard and PPFD-specific pathways.
Project description: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.
Project description:We compared the proteome of dry as well as germinating seeds of Arabidopsis thaliana wild type Col-0 with the respective proteomes from an umk2 (AT4G25280) frameshift mutant.
Germinating seeds were incubated for 48 hours in 1/2-MS medium in Petri dishes at 4 degree Celsius followed by 24 hours of a phytochamber under long-day conditions.
Protein extraction, digestion by SP3 workflow, and LC-IMS-MS/MS analysis as described in https://doi.org/10.1038/s41477-022-01308-6.
Project description:To further elucidate the translational roles of NCR1 involed in drought stress, we conducted a comparative leaf proteomic analysis of 24-day-old ncr1 mutant and WT plants under well-watered and drought stress conditions.
Project description:Tissue-specific translatome profiles in Arabidopsis thaliana grown under long-day conditions with or without supplemental far-red light
Project description:In bacteria, the biosynthesis of cysteine is accomplished by two enzymes that are encoged by the cysK and cysM genes. CysM is also able to incorporate thiosulfate to produce S-sulfocysteine. In plant cells, the biosynthesis of cysteine occurs in the cytosol, mitochondria and chloroplasts. Chloroplasts contain two O-acetylserine(thiol)lyase homologs, which are encoded by the OAS-B and CS26 genes. An in vitro enzymatic analysis of the recombinant CS26 protein demonstrated that this isoform possesses S-sulfocysteine synthase activity and lacks O-acetylserine(thiol)lyase activity. In vivo functional analysis of this enzyme in knockout mutants demonstrated that mutation of cs26 suppressed the S-sulfocysteine synthase activity that was detected in wild type; furthermore, the mutants exhibited a growth phenotype, but penetrance depended on the light regime. The cs26 mutant plants also had reductions in chlorophyll content and photosynthetic activity (neither of which were observed in oas-b mutants), as well as elevated glutathione levels. However, cs26 leaves were not able to properly detoxify ROS, which accumulated to high levels under long-day growth conditions. The transcriptional profile of the cs26 mutant revealed that the mutation had a pleiotropic effect on many cellular and metabolic processes. Our finding reveals that S-sulfocysteine and the activity of S-sulfocysteine synthase play an important role in chloroplast function and are essential for light-dependent redox regulation within the chloroplast. Using the Affymetrix ATH1 GeneChips, we performed a comparative transcriptomic analysis on leaves of the cs26 and wild type plants under two different photoperiod conditions. Wild type and cs26 mutant plants were grown on soil under a long-day photoperiod (LD) or under a short-day photoperiod (SD). Total RNA was extracted from the leaves of 3-week-old plants grown under identical LD conditions, and from the leaves of 5-week-old plants grown under identical SD conditions. Three biological replicates were performed for each sample and hybridized to the chips. We made two different comparisons to classify the differently expressed genes in the mutant plant: cs26 leaves under LD versus wild-type leaves under LD and cs26 leaves under SD versus wild-type leaves under SD.