Singlet Oxygen Plays an Essential Role in the Root's Response to Osmotic Stress.
Plant Physiol
; 177(4): 1717-1727, 2018 08.
Article
em En
| MEDLINE
| ID: mdl-29954869
ABSTRACT
The high osmotic potentials in plants subjected to drought stress can be mimicked by the application of high molecular weight polyethylene glycol. Here, we quantified the effects of exposure to polyethylene glycol on the growth of the main and lateral roots of Arabidopsis (Arabidopsis thaliana) seedlings. The effects on root growth were highly correlated with the appearance of singlet oxygen, as visualized using the singlet oxygen-specific probe singlet oxygen sensor green. The production of singlet oxygen was followed by cell death, as indicated by the intracellular accumulation of propidium iodide due to the loss of membrane integrity. Cell death began in the epidermal region of the root tip and spread in a dynamic manner to meristematic sections. In parallel, gene expression changes specific to the presence of singlet oxygen were observed. The accumulation of other reactive oxygen species, namely hydrogen, peroxide, nitric oxide, and superoxide, did not correlate with cell death. In addition, both the singlet oxygen scavenger His and the lipoxygenase inhibitor salicylhydroxamic acid specifically inhibited singlet oxygen accumulation and cell death. These results suggest a light-independent, type-I source of singlet oxygen production. Serpin-protease interactions were used as a model to assess the possibility of vacuolar-type cell death. Osmotic stress induced the accumulation of complexes between the cytoplasmic serpin AtSERPIN1 and its cognate vacuolar proteases, indicating that vacuolar integrity was compromised. These findings imply that singlet oxygen plays an essential role in conveying the root response to osmotic stress.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Pressão Osmótica
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Arabidopsis
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Raízes de Plantas
/
Oxigênio Singlete
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant Physiol
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Israel