Identification of cyclic GMP-activated nonselective Ca2+-permeable cation channels and associated CNGC5 and CNGC6 genes in Arabidopsis guard cells.

Cytosolic Ca(2+) in guard cells plays an important role in stomatal movement responses to environmental stimuli. These cytosolic Ca(2+) increases result from Ca(2+) influx through Ca(2+)-permeable channels in the plasma membrane and Ca(2+) release from intracellular organelles in guard cells. However, the genes encoding defined plasma membrane Ca(2+)-permeable channel activity remain unknown in guard cells and, with some exceptions, largely unknown in higher plant cells.

ERD15--an attenuator of plant ABA responses and stomatal aperture.

Plants are continuously challenged by abiotic and biotic stress factors and need to mount appropriate responses to ensure optimal growth and survival. We have identified ERD15 as a central component in several stress responses in Arabidopsis thaliana. Comparative genomics demonstrates that ERD15 is a member of a small but highly conserved protein family ubiquitous but specific to the plant kingdom.

Ozone-triggered rapid stomatal response involves the production of reactive oxygen species, and is controlled by SLAC1 and OST1.

The air pollutant ozone can be used as a tool to unravel in planta processes induced by reactive oxygen species (ROS). Here, we have utilized ozone to study ROS-dependent stomatal signaling. We show that the ozone-triggered rapid transient decrease (RTD) in stomatal conductance coincided with a burst of ROS in guard cells.

Natural variation in ozone sensitivity among Arabidopsis thaliana accessions and its relation to stomatal conductance.

Genetic variation between naturally occurring populations provides a unique source to unravel the complex mechanisms of stress tolerance. Here, we have analysed O(3) sensitivity of 93 natural Arabidopsis thaliana accessions together with five O(3)-sensitive mutants to acute O(3) exposure. The variation in O(3) sensitivity among the natural accessions was much higher than among the O(3)-sensitive mutants and corresponding wild types.