Dissection of the ozone‐induced calcium signature

Reactive Oxygen Species in the Regulation of Stomatal Movements

“…H 2 O 2 inhibited both inward-and outward-rectifying K + channels in V. faba guard cells (Zhang et al, 2001a;Köhler et al, 2003) and activated Ca 2+ -permeable cation channels in Arabidopsis guard cells (Pei et al, 2000). Analogously, O 3 induced a biphasic cytosolic Ca 2+ elevation within seconds of exposure (Clayton et al, 1999;Evans et al, 2005), and a recovery period was needed before the Ca 2+ elevation could be elicited again (Evans et al, 2005). Furthermore, Arabidopsis seedlings distinguished H 2 O 2 from ozone; plants still produced the Ca 2+ signal in response to ozone after becoming refractory to H 2 O 2 , and vice versa, suggesting specificity to different forms of ROS (Evans et al, 2005).…”

Double Jeopardy

“…On the other hand, ozone-induced expression of GST , a general cellular protectant, was suppressed strongly in the OX line, but its expression was delayed markedly in the RI line. In Arabidopsis, both hydrogen peroxide and ozone induce GST expression (Clayton et al, 1999;Grant et al, 2000), and this expression has been demonstrated to require the activity of an unidentified 48-kD MAPK and calcium ion influx. Calcium channel activity also is essential for the ROS activation of SIPK in tobacco (Samuel et al, 2000).…”

Transcriptomic Analysis Reveals Calcium Regulation of Specific Promoter Motifs inArabidopsis

“…Calcium has been shown to be necessary as well as sufficient for expression of some plant genes, such as GST1 in response to ozone (Clayton et al, 1999) and KIN1 and KIN2 in response to cold in Arabidopsis (Knight et al, 1996;Tä htiharju et al, 1997). In a previous study, we broadened the scope of this method of inquiry by testing the expression of 6120 genes in response to a chemical calcium agonist.…”