Multifaceted Role of Salicylic Acid in Combating Cold Stress in Plants: A Review

Salicylic acid (SA) is well known hormonal molecule involved in cell death regulation. In response to a broad range of environmental factors (e.g., high light, UV, pathogens attack), plants accumulate SA, which participates in cell death induction and spread in some foliar cells. LESION SIMULATING DISEASE 1 (LSD1) is one of the best-known cell death regulators in Arabidopsis thaliana. The lsd1 mutant, lacking functional LSD1 protein, accumulates SA and is conditionally susceptible to many biotic and abiotic stresses. In order to get more insight into the role of LSD1-dependent regulation of SA accumulation during cell death, we crossed the lsd1 with the sid2 mutant, caring mutation in ISOCHORISMATE SYNTHASE 1(ICS1) gene and having deregulated SA synthesis, and with plants expressing the bacterial nahG gene and thus decomposing SA to catechol. In response to UV A+B irradiation, the lsd1 mutant exhibited clear cell death phenotype, which was reversed in lsd1/sid2 and lsd1/NahG plants. The expression of PR-genes and the H2O2 content in UV-treated lsd1 were significantly higher when compared with the wild type. In contrast, lsd1/sid2 and lsd1/NahG plants demonstrated comparability with the wild-type level of PR-genes expression and H2O2. Our results demonstrate that SA accumulation is crucial for triggering cell death in lsd1, while the reduction of excessive SA accumulation may lead to a greater tolerance toward abiotic stress.

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Arabidopsis Disulfide Reductase, Trx-h2, Functions as an RNA Chaperone under Cold Stress

Applied Sciences ◽

10.3390/app11156865 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6865

Author(s):

Eun Seon Lee ◽

Joung Hun Park ◽

Seong Dong Wi ◽

Ho Byoung Chae ◽

Seol Ki Paeng ◽

...

Keyword(s):

Cold Stress ◽

Wild Type ◽

Rna Chaperone ◽

E Coli ◽

Cold Sensitive ◽

Thioredoxin H ◽

Functional Rnas

The thioredoxin-h (Trx-h) family of Arabidopsis thaliana comprises cytosolic disulfide reductases. However, the physiological function of Trx-h2, which contains an additional 19 amino acids at its N-terminus, remains unclear. In this study, we investigated the molecular function of Trx-h2 both in vitro and in vivo and found that Arabidopsis Trx-h2 overexpression (Trx-h2OE) lines showed significantly longer roots than wild-type plants under cold stress. Therefore, we further investigated the role of Trx-h2 under cold stress. Our results revealed that Trx-h2 functions as an RNA chaperone by melting misfolded and non-functional RNAs, and by facilitating their correct folding into active forms with native conformation. We showed that Trx-h2 binds to and efficiently melts nucleic acids (ssDNA, dsDNA, and RNA), and facilitates the export of mRNAs from the nucleus to the cytoplasm under cold stress. Moreover, overexpression of Trx-h2 increased the survival rate of the cold-sensitive E. coli BX04 cells under low temperature. Thus, our data show that Trx-h2 performs function as an RNA chaperone under cold stress, thus increasing plant cold tolerance.

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Halloysite nanotubes filled with salicylic acid and sodium diclofenac: effects of vacuum pumping on loading and release properties

Journal of Nanostructure in Chemistry ◽

10.1007/s40097-021-00391-z ◽

2021 ◽

Author(s):

Lorenzo Lisuzzo ◽

Giuseppe Cavallaro ◽

Stefana Milioto ◽

Giuseppe Lazzara

Keyword(s):

Salicylic Acid ◽

Release Kinetics ◽

Halloysite Nanotubes ◽

Drug Molecules ◽

Sodium Diclofenac ◽

Tunable Release ◽

Feature Based ◽

Kinetics Of ◽

Filling Mechanism

AbstractIn this work, we investigated the effects of the vacuum pumping on both the loading efficiencies and the release kinetics of halloysite nanotubes filled with drug molecules dissolved in ethanol. As model drugs, salicylic acid and sodium diclofenac were selected. For comparison, the loading of the drug molecules was conducted on platy kaolinite to explore the key role of the hollow tubular morphology on the filling mechanism of halloysite. The effects of the pressure conditions used in the loading protocol were interpreted and discussed on the basis of the thermodynamic results provided by Knudsen thermogravimetry, which demonstrated the ethanol confinement inside the halloysite cavity. Several techniques (TEM, FTIR spectroscopy, DLS and $$\zeta$$ ζ -potential experiments) were employed to characterize the drug filled nanoclays. Besides, release kinetics of the drugs were studied and interpreted according to the loading mechanism. This work represents a further step for the development of nanotubular carriers with tunable release feature based on the loading protocol and drug localization into the carrier. Graphic abstract The filling efficiency of halloysite nanotubes is enhanced by the reduction of the pressure conditions used in the loading protocol.

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The AaCBF4-AaBAM3.1 module enhances freezing tolerance of kiwifruit (Actinidia arguta)

Horticulture Research ◽

10.1038/s41438-021-00530-1 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Shihang Sun ◽

Chungen Hu ◽

Xiujuan Qi ◽

Jinyong Chen ◽

Yunpeng Zhong ◽

...

Keyword(s):

Cold Stress ◽

Freezing Tolerance ◽

Luciferase Reporter ◽

Dna Interactions ◽

Functional Protein ◽

Actinidia Arguta ◽

Protein Dna Interactions ◽

Similar Phenotype ◽

Reporter Assays

AbstractBeta-amylase (BAM) plays an important role in plant resistance to cold stress. However, the specific role of the BAM gene in freezing tolerance is poorly understood. In this study, we demonstrated that a cold-responsive gene module was involved in the freezing tolerance of kiwifruit. In this module, the expression of AaBAM3.1, which encodes a functional protein, was induced by cold stress. AaBAM3.1-overexpressing kiwifruit lines showed increased freezing tolerance, and the heterologous overexpression of AaBAM3.1 in Arabidopsis thaliana resulted in a similar phenotype. The results of promoter GUS activity and cis-element analyses predicted AaCBF4 to be an upstream transcription factor that could regulate AaBAM3.1 expression. Further investigation of protein-DNA interactions by using yeast one-hybrid, GUS coexpression, and dual luciferase reporter assays confirmed that AaCBF4 directly regulated AaBAM3.1 expression. In addition, the expression of both AaBAM3.1 and AaCBF4 in kiwifruit responded positively to cold stress. Hence, we conclude that the AaCBF-AaBAM module is involved in the positive regulation of the freezing tolerance of kiwifruit.

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GRAS-domain transcription factor PAT1 regulates jasmonic acid biosynthesis in grape cold stress response

Plant Physiology ◽

10.1093/plphys/kiab142 ◽

2021 ◽

Author(s):

Zemin Wang ◽

Darren Chern Jan Wong ◽

Yi Wang ◽

Guangzhao Xu ◽

Chong Ren ◽

...

Keyword(s):

Stress Response ◽

Cold Stress ◽

Cold Tolerance ◽

Cold Treatment ◽

Ectopic Expression ◽

Bimolecular Fluorescence Complementation ◽

Luciferase Reporter ◽

Vitis Amurensis ◽

Mobility Shift

Abstract Cultivated grapevine (Vitis) is a highly valued horticultural crop, and cold stress affects its growth and productivity. Wild Amur grape (Vitis amurensis) PAT1 (Phytochrome A signal transduction 1, VaPAT1) is induced by low temperature, and ectopic expression of VaPAT1 enhances cold tolerance in Arabidopsis (Arabidopsis thaliana). However, little is known about the molecular mechanism of VaPAT1 during the cold stress response in grapevine. Here, we confirmed the overexpression of VaPAT1 in transformed grape calli enhanced cold tolerance. Yeast two-hybrid and bimolecular fluorescence complementation assays highlighted an interaction between VaPAT1 with INDETERMINATE-DOMAIN 3 (VaIDD3). A role of VaIDD3 in cold tolerance was also indicated. Transcriptome analysis revealed VaPAT1 and VaIDD3 overexpression and cold treatment coordinately modulate the expression of stress-related genes including lipoxygenase 3 (LOX3), a gene encoding a key jasmonate biosynthesis enzyme. Co-expression network analysis indicated LOX3 might be a downstream target of VaPAT1. Both electrophoretic mobility shift and dual luciferase reporter assays showed the VaPAT1-IDD3 complex binds to the IDD-box (AGACAAA) in the VaLOX3 promoter to activate its expression. Overexpression of both VaPAT1 and VaIDD3 increased the transcription of VaLOX3 and JA levels in transgenic grape calli. Conversely, VaPAT1-SRDX (dominant repression) and CRISPR/Cas9-mediated mutagenesis of PAT1-ED causing the loss of the C-terminus in grape calli dramatically prohibited the accumulation of VaLOX3 and JA levels during cold treatment. Together, these findings point to a pivotal role of VaPAT1 in the cold stress response in grape by regulating JA biosynthesis.

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Mechanisms of Colorectal Cancer Prevention by Aspirin—A Literature Review and Perspective on the Role of COX-Dependent and -Independent Pathways

International Journal of Molecular Sciences ◽

10.3390/ijms21239018 ◽

2020 ◽

Vol 21 (23) ◽

pp. 9018

Author(s):

Ranjini Sankaranarayanan ◽

D. Ramesh Kumar ◽

Meric A. Altinoz ◽

G. Jayarama Bhat

Keyword(s):

Salicylic Acid ◽

Cancer Prevention ◽

Protective Actions ◽

Direct Exposure ◽

Anti Cancer ◽

Chemopreventive Effect ◽

Colorectal Cancer Prevention ◽

Preclinical And Clinical Studies ◽

Shed Light

Aspirin, synthesized and marketed in 1897 by Bayer, is one of the most widely used drugs in the world. It has a well-recognized role in decreasing inflammation, pain and fever, and in the prevention of thrombotic cardiovascular diseases. Its anti-inflammatory and cardio-protective actions have been well studied and occur through inhibition of cyclooxygenases (COX). Interestingly, a vast amount of epidemiological, preclinical and clinical studies have revealed aspirin as a promising chemopreventive agent, particularly against colorectal cancers (CRC); however, the primary mechanism by which it decreases the occurrences of CRC has still not been established. Numerous mechanisms have been proposed for aspirin’s chemopreventive properties among which the inhibition of COX enzymes has been widely discussed. Despite the wide attention COX-inhibition has received as the most probable mechanism of cancer prevention by aspirin, it is clear that aspirin targets many other proteins and pathways, suggesting that these extra-COX targets may also be equally important in preventing CRC. In this review, we discuss the COX-dependent and -independent pathways described in literature for aspirin’s anti-cancer effects and highlight the strengths and limitations of the proposed mechanisms. Additionally, we emphasize the potential role of the metabolites of aspirin and salicylic acid (generated in the gut through microbial biotransformation) in contributing to aspirin’s chemopreventive actions. We suggest that the preferential chemopreventive effect of aspirin against CRC may be related to direct exposure of aspirin/salicylic acid or its metabolites to the colorectal tissues. Future investigations should shed light on the role of aspirin, its metabolites and the role of the gut microbiota in cancer prevention against CRC.

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