Dataset Information

Glycosylated Sterols Enhance Cold Tolerance in Tomato via Membrane Stabilization and Jasmonate Signaling

ABSTRACT: Free and glycosylated sterols play a central role in maintaining the structural integrity and proper functioning of plasma membrane, which serves as the primary sensor of cold and initiates signaling cascades to mitigate chilling-induced damage. Here we characterize the cold response of tomato (Micro-Tom) mutants with opposite glycosylated to free sterol ratio resulting from the overexpression and silencing of the sterol glycosyltransferases SlSGT2 and SlSGT1. A high ratio in the SlSGT2 overexpressing mutants increases cold tolerance, membrane stability, and oxidative stress responses, while a low ratio in the SlSGT1-silenced mutants causes the opposite phenotypes. The different cold sensitivity in these mutants is due to the altered membrane sterol profiles, rather than to a different capacity to adjust sterol levels during cold exposure. Changes in the glycosylated to free sterol ratio also trigger distinct transcriptional programs that establish a preconditioned stress-responsive state under basal conditions and a more efficient response under cold exposure in the SlSGT2 overexpressing mutants and compromise the capacity to withstand the effects of cold stress in the SlSGT1-silenced mutants. The SlSGT2 overexpressing mutants accumulate higher basal levels of jasmonates and display enhanced biosynthetic capacity under cold stress compared to SlSGT1-silenced and control plants. The elevated glycosylated to free sterol ratio in SlSGT2 overexpressing mutants facilitates JA biosynthesis and signaling, leading to the activation of cold-responsive genes, including those of the CBF–COR pathway, antioxidant defenses and polyamine biosynthesis. Our findings provide key insights into the mechanisms by which glycosylated sterols improve cold tolerance in tomato.

ORGANISM(S): Solanum lycopersicum

PROVIDER: GSE292957 | GEO | 2025/09/30

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Liposomal amphotericin B is an important frontline drug for the treatment of visceral leishmaniasis, a neglected disease of poverty. The mechanism of action of amphotericin B (AmB) is thought to involve interaction with ergosterol and other ergostane sterols, resulting in disruption of the integrity and key functions of the plasma membrane. Emergence of clinically refractory isolates of L. donovani and L. infantum is an ongoing issue and knowledge of potential resistance mechanisms can help to alleviate this problem. Here we report the characterisation of four independently selected L. donovani clones that are resistant to AmB. Whole genome sequencing revealed that in three of the moderately resistant clones, resistance was due solely to the deletion of a gene encoding C24-sterol methyltransferase (SMT1). The fourth, hyper-resistant resistant clone (>60-fold) was found to have a 24 bp deletion in both alleles of a gene encoding a putative cytochrome P450 reductase (P450R1). Metabolic profiling indicated these parasites were virtually devoid of ergosterol (0.2% versus 18% of total sterols in wild-type) and had a marked accumulation of 14-methylfecosterol (75% versus 0.1% of total sterols in wild-type) and other 14-alpha methylcholestanes. These are substrates for sterol 14-alpha demethylase (CYP51) suggesting that this enzyme is a bona fide P450R specifically involved in electron transfer from NADPH to CYP51 during catalysis. Deletion of P450R1 in wild-type cells phenocopied the metabolic changes observed in our AmB hyper-resistant clone as well as in CYP51 nulls. Likewise, addition of a wild type P450R1 gene restored sterol profiles to wild type. Our studies indicate that P450R1 is essential for L. donovani amastigote viability, thus loss of this gene is unlikely to be a driver of clinical resistance. Nevertheless, investigating the mechanisms underpinning AmB resistance in these cells provided insights that refine our understanding of the L. donovani sterol biosynthetic pathway.

Project description:Fungal infections are a serious health problem in clinics especially in the immune-compromised patient. Disease ranges from widespread superficial infections like vulvovaginal infections to life-threatening systemic candidiasis. Especially for systemic mycoses only a limited arsenal of antifungals is available. The most commonly used classes of antifungal compounds used include azoles, polyenes and echinocandines. Due to emerging resistance to standard therapy and significant side effects and high costs for several antifungals.,there is a medical need for new antifungals in the clinic and general practice. In order to expand the arsenal of compounds with antifungal activities we previously screened a compound library, using a new type of activity-selectivity (AS) assay analysing both the antifungal activity and the compatibility with human cells at the same time. One compound, ((S)-2-(1-aminoisobutyl)-1-(3-chlorobenzyl) benzimidazole (EMC120B12)), showed high antifungal activity against several species of pathogenic yeasts including C. glabrata and C. krusei, species which are highly refractory to antifungals, especially to the commonly used azoles. Here we could show by transcriptional profiling and sterol analysis that the target of this new antifungal compound is the ergosterol pathway. The effects of EMC120B12 on sterol biosynthesis mimic those of fluconazole, strongly indicating that EMC120B12 also targets ERG11 like the azols. But not only the marker sterol 14 methylergosta 8,24(28) dien 3β,6α diol accumulated in C. krusei under EMC120B12 treatment, but also hitherto unknown related sterols. The novel sterols have a 3β,6α diol structure. Furthermore, this is the first time that a benzimidazole structure has been shown to result in a block of the sterol pathway by accumulating marker sterols connected to ERG11 inactivation. In total, three biological replicates were performed. All experiments were performed as dye swaps. Thus, in total 18 arrays have been hybridzed. Hybridization experiments included an untreated reference sample and a sample of cells treated with either ((1S)-1-[1-(3-chlorobenzyl)-1H-benzimidazol-2-yl]-2-methylpropyl-amine) (EMC120B12), Fluconazole or Nocodazole. The array included one technical replicate of each probe.

Dataset Information

Glycosylated Sterols Enhance Cold Tolerance in Tomato via Membrane Stabilization and Jasmonate Signaling

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets