Role of salicylic acid in alleviating the inhibition of root elongation by suppressing ethylene emission in rice under Al toxicity conditions

2019 ◽  
Vol 90 (3) ◽  
pp. 475-487 ◽  
Author(s):  
Chun Quan Zhu ◽  
Wen Jun Hu ◽  
Xiao Chuang Cao ◽  
Lian Feng Zhu ◽  
Zhi Gang Bai ◽  
...  
Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 962
Author(s):  
Maciej Jerzy Bernacki ◽  
Anna Rusaczonek ◽  
Weronika Czarnocka ◽  
Stanisław Karpiński

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.


Author(s):  
Lorenzo Lisuzzo ◽  
Giuseppe Cavallaro ◽  
Stefana Milioto ◽  
Giuseppe Lazzara

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.


2020 ◽  
Vol 21 (23) ◽  
pp. 9018
Author(s):  
Ranjini Sankaranarayanan ◽  
D. Ramesh Kumar ◽  
Meric A. Altinoz ◽  
G. Jayarama Bhat

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.


2013 ◽  
Vol 61 (2) ◽  
pp. 161-172 ◽  
Author(s):  
M. Pál ◽  
O. Gondor ◽  
T. Janda

Low temperature is one of the most important limiting factors for plant growth throughout the world. Exposure to low temperature may cause various phenotypic and physiological symptoms, and may result in oxidative stress, leading to loss of membrane integrity and to the impairment of photosynthesis and general metabolic processes. Salicylic acid (SA), a phenolic compound produced by a wide range of plant species, may participate in many physiological and metabolic reactions in plants. It has been shown that exogenous SA may provide protection against low temperature injury in various plant species, while various stress factors may also modify the synthesis and metabolism of SA. In the present review, recent results on the effects of SA and related compounds in processes leading to acclimation to low temperatures will be discussed.


2003 ◽  
Vol 16 (11) ◽  
pp. 1022-1029 ◽  
Author(s):  
Pradeep Kachroo ◽  
Aardra Kachroo ◽  
Ludmila Lapchyk ◽  
David Hildebrand ◽  
Daniel F. Klessig

The Arabidopsis mutants ssi2 and fab2 are defective in stearoyl ACP desaturase, which causes altered salicylic acid (SA)- and jasmonic acid (JA)-mediated defense signaling. Both ssi2 and fab2 plants show spontaneous cell death, express PR genes constitutively, accumulate high levels of SA, and exhibit enhanced resistance to bacterial and oomycete pathogens. In contrast to constitutive activation of the SA pathway, ssi2 and fab2 plants are repressed in JA-mediated induction of the PDF1.2 gene, which suggests that the SSI2-mediated signaling pathway modulates cross talk between the SA and JA pathways. In this study, we have characterized two recessive nonallelic mutants in the ssi2 background, designated as rdc (restorer of defective cross talk) 2 and rdc8. Both ssi2 rdc mutants are suppressed in constitutive SA signaling, show basal level expression of PR-1 gene, and induce high levels of PDF1.2 in response to exogenous application of JA. Interestingly, while the rdc8 mutation completely abolishes spontaneous cell death in ssi2 rdc8 plants, the ssi2 rdc2 plants continue to show some albeit reduced cell death. Fatty acid (FA) analysis showed a reduction in 16:3 levels in ssi2 rdc8 plants, which suggests that this mutation may limit the flux of FAs into the pro-karyotic pathway of glycerolipid biosynthesis. Both rdc2 and rdc8 continue to accumulate high levels of 18:0, which suggests that 18:0 levels were responsible for neither constitutive SA signaling nor repression of JA-induced expression of the PDF1.2 gene in ssi2 plants. We also analyzed SA and JA responses of the fab2-derived shs1 mutant, which accumulates levels of 18:0 over 50% lower than those in the fab2 plants. Even though fab2 shs1 plants were morphologically bigger than fab2 plants, they expressed PR genes constitutively, showed HR-like cell death, and accumulated elevated levels of SA. However, unlike the ssi2 rdc plants, fab2 shs1 plants were unable to induce high levels of PDF1.2 expression in response to exogenous application of JA. Together, these results show that defective cross talk in ssi2 can be restored by second site mutations and is independent of morphological size of the plants, cell death, and elevated levels of 18:0.


Author(s):  
José A. Hernández ◽  
Pedro Diaz-Vivancos ◽  
Gregorio Barba-Espín ◽  
María José Clemente-Moreno

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