Cardenolide Increase in Foxglove During Stresses Corresponds to Cholesterol and Phytosterol Biosynthesis

Cardenolides are a group of steroidal metabolites found in Digitalis lanata with potent cardioactive effects on animals. In plants, cardenolides are involved in various stress responses. However, the molecular mechanism of cardenolide increase during stresses is mostly unknown. Here we show that cardenolides were increased upon methyl jasmonate (MJ), sorbitol, potassium (KCl) chloride, and salicylic acid analog (BTH: 2,1,3-benzothiadiazole) treatments. However, the expression of three known genes for cardenolide biosynthesis did not correlate well with these increases. Specifically, the expression of progesterone-5β-reductases (P5βR and P5βR2) did not correlate with cardenolide increase. The expression of 3β-hydroxysteroid dehydrogenase (3βHSD) correlated with cardenolide levels only during the BTH treatment. Mining the D. lanata transcriptome identified genes involved in cholesterol and phytosterol biosynthesis: SSR1 (sterol sidechain reductase), SMO1, and SMO3 (sterol methyl oxidase). Surprisingly, the expression of all three genes correlated well with the cardenolide increase after BTH treatment. Phylogenetic analysis showed that SSR1 is likely involved in both cholesterol and phytosterol biosynthesis. In addition, SMO1 is likely specific to phytosterol biosynthesis, and SMO3 is specific to cholesterol biosynthesis. These results suggest that both cholesterol and phytosterol are involved in cardenolide biosynthesis. In summary, this work shows that cardenolides are important for stress responses in D. lanata and revealed a novel relationship between phytosterol and cardenolide biosynthesis.

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Expression Analysis of Defense-Related Genes in Cotton (Gossypium hirsutum) after Fusarium oxysporum f. sp. vasinfectum Infection and Following Chemical Elicitation using a Salicylic Acid Analog and Methyl Jasmonate

Plant Molecular Biology Reporter ◽

10.1007/s11105-011-0335-0 ◽

2011 ◽

Vol 30 (1) ◽

pp. 225-234 ◽

Cited By ~ 21

Author(s):

Antonios G. Zambounis ◽

Mairi S. Kalamaki ◽

Eleni E. Tani ◽

Epameinondas J. Paplomatas ◽

Athanasios S. Tsaftaris

Keyword(s):

Salicylic Acid ◽

Gossypium Hirsutum ◽

Methyl Jasmonate ◽

Fusarium Oxysporum ◽

Expression Analysis ◽

Acid Analog

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Cloning and Characterization of Promoters of the Fungal Immunomodulatory Protein Genes from Ganoderma spp. (Agaricomycetes) and Their Response to Methyl Jasmonate and Salicylic Acid

International Journal of Medicinal Mushrooms ◽

10.1615/intjmedmushrooms.2018025451 ◽

2018 ◽

Vol 20 (2) ◽

pp. 177-189 ◽

Cited By ~ 1

Author(s):

Qi-Zhang Li ◽

Yu-Zhou Chang ◽

Kai-Qi Su ◽

Xiao-Lei Wang ◽

Xiao-Hui Bai ◽

...

Keyword(s):

Salicylic Acid ◽

Methyl Jasmonate ◽

Fungal Immunomodulatory Protein ◽

Immunomodulatory Protein

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Effect of RIP Overexpression on Abiotic Stress Tolerance and Development of Rice

International Journal of Molecular Sciences ◽

10.3390/ijms22031434 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1434

Author(s):

Pieter Wytynck ◽

Jeroen Lambin ◽

Simin Chen ◽

Sinem Demirel Asci ◽

Isabel Verbeke ◽

...

Keyword(s):

Methyl Jasmonate ◽

Stress Responses ◽

Abiotic Stress Tolerance ◽

Protein Translation ◽

Ribosome Inactivating Proteins ◽

Close Proximity ◽

Inhibit Protein Translation ◽

Plant Ribosomes ◽

A Cell ◽

Type 3

Ribosome-inactivating proteins (RIPs) are a class of cytotoxic enzymes that can inhibit protein translation by depurinating rRNA. Most plant RIPs are synthesized with a leader sequence that sequesters the proteins to a cell compartment away from the host ribosomes. However, several rice RIPs lack these signal peptides suggesting they reside in the cytosol in close proximity to the plant ribosomes. This paper aims to elucidate the physiological function of two nucleocytoplasmic RIPs from rice, in particular, the type 1 RIP referred to as OsRIP1 and a presumed type 3 RIP called nuRIP. Transgenic rice lines overexpressing these RIPs were constructed and studied for developmental effects resulting from this overexpression under greenhouse conditions. In addition, the performance of transgenic seedlings in response to drought, salt, abscisic acid and methyl jasmonate treatment was investigated. Results suggest that both RIPs can affect methyl jasmonate mediated stress responses.

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The Arabidopsis mediator complex subunit 8 regulates oxidative stress responses

The Plant Cell ◽

10.1093/plcell/koab079 ◽

2021 ◽

Cited By ~ 1

Author(s):

Huaming He ◽

Jordi Denecker ◽

Katrien Van Der Kelen ◽

Patrick Willems ◽

Robin Pottie ◽

...

Keyword(s):

Oxidative Stress ◽

Gene Expression ◽

Salicylic Acid ◽

Jasmonic Acid ◽

Stress Responses ◽

Negative Regulator ◽

Mediator Complex ◽

Defense Gene Expression ◽

A Genome ◽

Oxidative Stress Responses

Abstract Signaling events triggered by hydrogen peroxide (H2O2) regulate plant growth and defense by orchestrating a genome-wide transcriptional reprogramming. However, the specific mechanisms that govern H2O2-dependent gene expression are still poorly understood. Here, we identify the Arabidopsis Mediator complex subunit MED8 as a regulator of H2O2 responses. The introduction of the med8 mutation in a constitutive oxidative stress genetic background (catalase-deficient, cat2) was associated with enhanced activation of the salicylic acid pathway and accelerated cell death. Interestingly, med8 seedlings were more tolerant to oxidative stress generated by the herbicide methyl viologen (MV) and exhibited transcriptional hyperactivation of defense signaling, in particular salicylic acid- and jasmonic acid-related pathways. The med8-triggered tolerance to MV was manipulated by the introduction of secondary mutations in salicylic acid and jasmonic acid pathways. In addition, analysis of the Mediator interactome revealed interactions with components involved in mRNA processing and microRNA biogenesis, hence expanding the role of Mediator beyond transcription. Notably, MED8 interacted with the transcriptional regulator NEGATIVE ON TATA-LESS, NOT2, to control the expression of H2O2-inducible genes and stress responses. Our work establishes MED8 as a component regulating oxidative stress responses and demonstrates that it acts as a negative regulator of H2O2-driven activation of defense gene expression.

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Salicylic acid ameliorates zinc and chromium-induced stress responses in wheat seedlings: a biochemical and computational analysis

Cereal Research Communications ◽

10.1007/s42976-021-00201-w ◽

2021 ◽

Author(s):

Muhammed Khairujjaman Mazumder ◽

Parul Sharma ◽

Debojyoti Moulick ◽

Sandeep Kumar Tata ◽

Shuvasish Choudhury

Keyword(s):

Salicylic Acid ◽

Stress Responses ◽

Computational Analysis ◽

Wheat Seedlings ◽

Induced Stress

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Epac1 regulates cellular SUMOylation by promoting the formation of SUMO-activating nuclear condensates

10.1101/2022.01.12.476066 ◽

2022 ◽

Author(s):

Wenli Yang ◽

William G Robichaux ◽

Fang C Mei ◽

Wel Lin ◽

Li Li ◽

...

Keyword(s):

Molecular Mechanism ◽

Stress Responses ◽

Foam Cell ◽

Low Density Lipoprotein ◽

Cellular Stress ◽

Cell Formation ◽

Density Lipoprotein ◽

Foam Cell Formation ◽

Intracellular Camp ◽

Protein Sumoylation

Protein SUMOylation plays an essential role in maintaining cellular homeostasis when cells are under stress. However, precisely how SUMOylation is regulated, and a molecular mechanism linking cellular stress to SUMOylation remains elusive. Herein, we report that cAMP, a major stress-response second messenger, acts through Epac1 as a regulator of cellular SUMOylation. The Epac1-associated proteome is highly enriched with components of the SUMOylation pathway. Activation of Epac1 by intracellular cAMP triggers phase separation and the formation of nuclear condensates containing Epac1 and general components of the SUMOylation machinery to promote cellular SUMOylation. Furthermore, genetic knockout of Epac1 obliterates oxidized low-density lipoprotein induced cellular SUMOylation in macrophages, leading to suppression of foam cell formation. These results provide a direct nexus connecting two major cellular stress responses to define a molecular mechanism in which cAMP regulates the dynamics of cellular condensates to modulate protein SUMOylation.

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