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Oxidative stress and NO signalling in the root apex as an early response to changes in gravity conditions.

Mugnai S, Pandolfi C, Masi E, Azzarello E, Monetti E, Comparini D, Voigt B, Volkmann D, Mancuso S - Biomed Res Int (2014)

Bottom Line: The same results were obtained by ROS measurement.The detrimental effect of D'orenone, disrupting the polarised auxin transport, on the onset of the oxygen peaks during the microgravity period was also evaluated.Results indicates an active role of NO and ROS as messengers during the gravitropic response, with probable implications in the auxin redistribution.

View Article: PubMed Central - PubMed

Affiliation: DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy ; HSO-USB, ESTEC, European Space Agency, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands.

ABSTRACT
Oxygen influx showed an asymmetry in the transition zone of the root apex when roots were placed horizontally on ground. The influx increased only in the upper side, while no changes were detected in the division and in the elongation zone. Nitric oxide (NO) was also monitored after gravistimulation, revealing a sudden burst only in the transition zone. In order to confirm these results in real microgravity conditions, experiments have been set up by using parabolic flights and drop tower. The production of reactive oxygen species (ROS) was also monitored. Oxygen, NO, and ROS were continuously monitored during normal and hyper- and microgravity conditions in roots of maize seedlings. A distinct signal in oxygen and NO fluxes was clearly detected only in the apex zone during microgravity, with no significant changes in normal and in hypergravity conditions. The same results were obtained by ROS measurement. The detrimental effect of D'orenone, disrupting the polarised auxin transport, on the onset of the oxygen peaks during the microgravity period was also evaluated. Results indicates an active role of NO and ROS as messengers during the gravitropic response, with probable implications in the auxin redistribution.

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Related in: MedlinePlus

Oxygen concentration in the solution measured at two different levels, close to (distance < 1 mm) the root apex and to the root mature zone during three different parabolas: one parabola at the beginning (a), one in the middle (b), and one at the end of the experiment (c). Control experiment with no roots inside the Eppendorf vial is shown in (d).
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fig4: Oxygen concentration in the solution measured at two different levels, close to (distance < 1 mm) the root apex and to the root mature zone during three different parabolas: one parabola at the beginning (a), one in the middle (b), and one at the end of the experiment (c). Control experiment with no roots inside the Eppendorf vial is shown in (d).

Mentions: A typical parabola is shown in Figure 4, with a period of microgravity (<0.05 g, 20–22 secs) inserted between two periods of hypergravity (1.8 g, 20 secs). Oxygen concentrations in the solution measured at two different root levels (root apex and mature zone) are also reported for three different parabolas. Bursts and peaks of oxygen concentration are clearly evident at root apex level during the microgravity periods, with significant detection during the entire flight. Interestingly, no peaks were detected in the mature zone and during hypergravity periods in the root apex. Control without seedlings showed no activity, demonstrating that the results previously shown were not related to a background noise of the microelectrodes during microgravity.


Oxidative stress and NO signalling in the root apex as an early response to changes in gravity conditions.

Mugnai S, Pandolfi C, Masi E, Azzarello E, Monetti E, Comparini D, Voigt B, Volkmann D, Mancuso S - Biomed Res Int (2014)

Oxygen concentration in the solution measured at two different levels, close to (distance < 1 mm) the root apex and to the root mature zone during three different parabolas: one parabola at the beginning (a), one in the middle (b), and one at the end of the experiment (c). Control experiment with no roots inside the Eppendorf vial is shown in (d).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150467&req=5

fig4: Oxygen concentration in the solution measured at two different levels, close to (distance < 1 mm) the root apex and to the root mature zone during three different parabolas: one parabola at the beginning (a), one in the middle (b), and one at the end of the experiment (c). Control experiment with no roots inside the Eppendorf vial is shown in (d).
Mentions: A typical parabola is shown in Figure 4, with a period of microgravity (<0.05 g, 20–22 secs) inserted between two periods of hypergravity (1.8 g, 20 secs). Oxygen concentrations in the solution measured at two different root levels (root apex and mature zone) are also reported for three different parabolas. Bursts and peaks of oxygen concentration are clearly evident at root apex level during the microgravity periods, with significant detection during the entire flight. Interestingly, no peaks were detected in the mature zone and during hypergravity periods in the root apex. Control without seedlings showed no activity, demonstrating that the results previously shown were not related to a background noise of the microelectrodes during microgravity.

Bottom Line: The same results were obtained by ROS measurement.The detrimental effect of D'orenone, disrupting the polarised auxin transport, on the onset of the oxygen peaks during the microgravity period was also evaluated.Results indicates an active role of NO and ROS as messengers during the gravitropic response, with probable implications in the auxin redistribution.

View Article: PubMed Central - PubMed

Affiliation: DISPAA, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino, Italy ; HSO-USB, ESTEC, European Space Agency, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands.

ABSTRACT
Oxygen influx showed an asymmetry in the transition zone of the root apex when roots were placed horizontally on ground. The influx increased only in the upper side, while no changes were detected in the division and in the elongation zone. Nitric oxide (NO) was also monitored after gravistimulation, revealing a sudden burst only in the transition zone. In order to confirm these results in real microgravity conditions, experiments have been set up by using parabolic flights and drop tower. The production of reactive oxygen species (ROS) was also monitored. Oxygen, NO, and ROS were continuously monitored during normal and hyper- and microgravity conditions in roots of maize seedlings. A distinct signal in oxygen and NO fluxes was clearly detected only in the apex zone during microgravity, with no significant changes in normal and in hypergravity conditions. The same results were obtained by ROS measurement. The detrimental effect of D'orenone, disrupting the polarised auxin transport, on the onset of the oxygen peaks during the microgravity period was also evaluated. Results indicates an active role of NO and ROS as messengers during the gravitropic response, with probable implications in the auxin redistribution.

Show MeSH
Related in: MedlinePlus