English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In the genus  Azolla  rapid abscission of roots from floating fronds occurs within minutes in response to a variety of stresses, including exposure to nitrite. We found that hydrogen peroxide, though itself not an inducer of root abscission, modulates nitrite-induced root abscission by  Azolla pinnata  in a dose-dependent manner, with 2 mM H 2 O 2  significantly diminishing the responsiveness to 2 mM NaNO 2 , and 10 mM H 2 O 2  slightly enhancing it. Hypoxia, which has been found in other plants to result in autogenic production of H 2 O 2 , dramatically stimulated root abscission of  A. pinnata  in response to nitrite, especially for plants previously cultivated in medium containing 5 mM KNO 3  compared to plants cultivated under N 2 -fixing conditions without combined nitrogen. Plants, including  Azolla , produce the small signaling molecule nitric oxide (NO) from nitrite using nitrate reductase. We found  Azolla  plants to display dose-dependent root abscission in response to the NO donor spermine NONOate. Treatment of plants with the thiol-modifying agents  S -methyl methanethiosulfonate or glutathione inhibited the nitrite-induced root abscission response. Synchrotron radiation-based Fourier transform infrared spectromicroscopy revealed higher levels of carbonylation in the abscission zone of dropped roots, indicative of reaction products of polysaccharides with potent free radical oxidants. We hypothesize that metabolic products of nitrite and NO react with H 2 O 2  in the apoplast leading to free-radical-mediated cleavage of structural polysaccharides and consequent rapid root abscission.

Bimodal effect of hydrogen peroxide and oxidative events in nitrite-induced rapid root abscission by the water fern Azolla pinnata