Elucidating the role of ascorbic acid in flowering and pathogen defense in Arabidopsis thaliana

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.

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Role of melatonin in UV‐B signaling pathway and UV‐B stress resistance in Arabidopsis thaliana

Plant Cell & Environment ◽

10.1111/pce.13879 ◽

2020 ◽

Vol 44 (1) ◽

pp. 114-129

Author(s):

Jing‐Wen Yao ◽

Zheng Ma ◽

Yan‐Qin Ma ◽

Ying Zhu ◽

Meng‐Qi Lei ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Signaling Pathway ◽

Stress Resistance

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Ambivalent role of ascorbic acid in the metal-catalyzed oxidation of oligopeptides

Journal of Inorganic Biochemistry ◽

10.1016/j.jinorgbio.2021.111510 ◽

2021 ◽

pp. 111510

Author(s):

Nikolett Bodnár ◽

Katalin Várnagy ◽

Lajos Nagy ◽

Gizella Csire ◽

Csilla Kállay

Keyword(s):

Ascorbic Acid ◽

Metal Catalyzed Oxidation ◽

Metal Catalyzed ◽

Catalyzed Oxidation

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Seed Gamma Irradiation of Arabidopsis thaliana ABA-Mutant Lines Alters Germination and Does Not Inhibit the Photosynthetic Efficiency of Juvenile Plants

Dose-Response ◽

10.1177/1559325820979249 ◽

2020 ◽

Vol 18 (4) ◽

pp. 155932582097924

Author(s):

Darya Babina ◽

Marina Podobed ◽

Ekaterina Bondarenko ◽

Elizaveta Kazakova ◽

Sofia Bitarishvili ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Growth Response ◽

Dose Range ◽

Fine Tuning ◽

Plant Tolerance ◽

Inhibitory Effects ◽

Γ Irradiation ◽

Photosynthetic Responses ◽

Mutant Lines

Plant growth response to γ-irradiation includes stimulating or inhibitory effects depending on plant species, dose applied, stage of ontogeny and other factors. Previous studies showed that responses to irradiation could depend on ABA accumulation and signaling. To elucidate the role of ABA in growth and photosynthetic responses to irradiation, lines Col-8, abi3-8 and aba3 -1 of Arabidopsis thaliana were used. Seeds were γ-irradiated using 60Co in the dose range 50-150 Gy. It was revealed that the dose of 150 Gy affected germination parameters of aba3 -1 and Col-8 lines, while abi3-8 line was the most resistant to the studied doses and even showed faster germination at early hours after γ-irradiation at 50 Gy. These results suggest that susceptibility to ABA is probably more important for growth response to γ-irradiation than ABA synthesis. The photosynthetic functioning of 16-day-old plants mainly was not disturbed by γ-irradiation of seeds, and no indication of photosystem II photoinhibition was noticed, revealing the robustness of the photosynthetic system of A. thaliana. Glutathione peroxidase activity and ABA concentrations in plant tissues were not affected in the studied dose range. These results contribute to the understanding of germination and photosynthesis fine-tuning and of mechanisms of plant tolerance to ionizing radiation.

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