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Production of reactive oxygen species and wound-induced resistance in Arabidopsis thaliana against Botrytis cinerea are preceded and depend on a burst of calcium.

Beneloujaephajri E, Costa A, L'Haridon F, Métraux JP, Binda M - BMC Plant Biol. (2013)

Bottom Line: The results of this study show that leaves treated with calcium channels inhibitors (verapamil) or calcium chelators (oxalate and EGTA) are impaired in ROS production.These data further extend our knowledge on the connection between wounding, calcium influx and ROS production.Moreover they provide for the first time the evidence that, following wounding, calcium changes precede a burst in ROS in the same location.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of biology, University of Fribourg, Ch, du Musée 10, 1700 Fribourg, Switzerland. matteo.binda@unifr.ch.

ABSTRACT

Background: Wounded leaves of Arabidopsis thaliana produce reactive oxygen species (ROS) within minutes after wounding and become resistant to the pathogenic fungus Botrytis cinerea at a local level. This fast response of the plants to the wound is called wound-induced resistance (WIR). However the molecular mechanisms of this response and the signal cascade between the wound and ROS production are still largely unknown. Calcium is a conserved signal and it is involved in many abiotic stress responses in plants, furthermore, calcium pathways act very fast.

Results: The results of this study show that leaves treated with calcium channels inhibitors (verapamil) or calcium chelators (oxalate and EGTA) are impaired in ROS production. Moreover, leaves treated with verapamil, EGTA or oxalate were more susceptible to B. cinerea after wounding. The intracellular measurements of calcium changes indicated quick but transient calcium dynamics taking place few seconds after wounding in cells neighbouring the wound site. This change in the cytosolic calcium was followed in the same region by a more stable ROS burst.

Conclusions: These data further extend our knowledge on the connection between wounding, calcium influx and ROS production. Moreover they provide for the first time the evidence that, following wounding, calcium changes precede a burst in ROS in the same location.

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Related in: MedlinePlus

Calcium is accumulated in the cytosol after wounding. Leaves that constitutively express cytosolic aequorin are incubated over-night in 10 μM CTZ, placed into a luminometer and then wounded. Luminescence was measured and depended on the amount of calcium that binds to aequorin and thus reflects cytosolic calcium influx. In the control, leaves were infiltrated with water, otherwise with the mentioned concentrations of calcium inhibitors.
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Figure 3: Calcium is accumulated in the cytosol after wounding. Leaves that constitutively express cytosolic aequorin are incubated over-night in 10 μM CTZ, placed into a luminometer and then wounded. Luminescence was measured and depended on the amount of calcium that binds to aequorin and thus reflects cytosolic calcium influx. In the control, leaves were infiltrated with water, otherwise with the mentioned concentrations of calcium inhibitors.

Mentions: To further examine if calcium signalling is involved in ROS accumulation upon wounding, we tested if wounding induces changes in the cytosolic calcium concentrations using transgenic A. thaliana plants expressing the photoprotein aequorin [8]. Basal level and stability of the luminescence signal before wounding were then assessed by introducing the leaves in a luminometer where luminescence was immediately scored every 3 seconds for one minute. After this time, leaves were wounded directly in the luminometer and readings were carried out for three more minutes. In water-infiltrated leaves, wounding resulted in reproducible kinetics composed of a strong and transient signal between 0 and 6s that was coincident with the wounding event (Figure 3). This first peak was followed by a second transient increase of lesser amplitude, taking place after around 25–30 seconds. This second peak of luminescence was abolished in inhibitor-treated leaves compared to controls.


Production of reactive oxygen species and wound-induced resistance in Arabidopsis thaliana against Botrytis cinerea are preceded and depend on a burst of calcium.

Beneloujaephajri E, Costa A, L'Haridon F, Métraux JP, Binda M - BMC Plant Biol. (2013)

Calcium is accumulated in the cytosol after wounding. Leaves that constitutively express cytosolic aequorin are incubated over-night in 10 μM CTZ, placed into a luminometer and then wounded. Luminescence was measured and depended on the amount of calcium that binds to aequorin and thus reflects cytosolic calcium influx. In the control, leaves were infiltrated with water, otherwise with the mentioned concentrations of calcium inhibitors.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4016300&req=5

Figure 3: Calcium is accumulated in the cytosol after wounding. Leaves that constitutively express cytosolic aequorin are incubated over-night in 10 μM CTZ, placed into a luminometer and then wounded. Luminescence was measured and depended on the amount of calcium that binds to aequorin and thus reflects cytosolic calcium influx. In the control, leaves were infiltrated with water, otherwise with the mentioned concentrations of calcium inhibitors.
Mentions: To further examine if calcium signalling is involved in ROS accumulation upon wounding, we tested if wounding induces changes in the cytosolic calcium concentrations using transgenic A. thaliana plants expressing the photoprotein aequorin [8]. Basal level and stability of the luminescence signal before wounding were then assessed by introducing the leaves in a luminometer where luminescence was immediately scored every 3 seconds for one minute. After this time, leaves were wounded directly in the luminometer and readings were carried out for three more minutes. In water-infiltrated leaves, wounding resulted in reproducible kinetics composed of a strong and transient signal between 0 and 6s that was coincident with the wounding event (Figure 3). This first peak was followed by a second transient increase of lesser amplitude, taking place after around 25–30 seconds. This second peak of luminescence was abolished in inhibitor-treated leaves compared to controls.

Bottom Line: The results of this study show that leaves treated with calcium channels inhibitors (verapamil) or calcium chelators (oxalate and EGTA) are impaired in ROS production.These data further extend our knowledge on the connection between wounding, calcium influx and ROS production.Moreover they provide for the first time the evidence that, following wounding, calcium changes precede a burst in ROS in the same location.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of biology, University of Fribourg, Ch, du Musée 10, 1700 Fribourg, Switzerland. matteo.binda@unifr.ch.

ABSTRACT

Background: Wounded leaves of Arabidopsis thaliana produce reactive oxygen species (ROS) within minutes after wounding and become resistant to the pathogenic fungus Botrytis cinerea at a local level. This fast response of the plants to the wound is called wound-induced resistance (WIR). However the molecular mechanisms of this response and the signal cascade between the wound and ROS production are still largely unknown. Calcium is a conserved signal and it is involved in many abiotic stress responses in plants, furthermore, calcium pathways act very fast.

Results: The results of this study show that leaves treated with calcium channels inhibitors (verapamil) or calcium chelators (oxalate and EGTA) are impaired in ROS production. Moreover, leaves treated with verapamil, EGTA or oxalate were more susceptible to B. cinerea after wounding. The intracellular measurements of calcium changes indicated quick but transient calcium dynamics taking place few seconds after wounding in cells neighbouring the wound site. This change in the cytosolic calcium was followed in the same region by a more stable ROS burst.

Conclusions: These data further extend our knowledge on the connection between wounding, calcium influx and ROS production. Moreover they provide for the first time the evidence that, following wounding, calcium changes precede a burst in ROS in the same location.

Show MeSH
Related in: MedlinePlus