Send to

Choose Destination
New Phytol. 2015 Dec;208(4):1126-37. doi: 10.1111/nph.13566. Epub 2015 Jul 20.

The HT1 protein kinase is essential for red light-induced stomatal opening and genetically interacts with OST1 in red light and CO2 -induced stomatal movement responses.

Author information

Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden.
Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, 812-8581, Japan.
Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, CA, 92093-0116, USA.


The question of whether red light-induced stomatal opening is mediated by a photosynthesis-derived reduction in intercellular [CO2 ] (Ci ) remains controversial and genetic analyses are needed. The Arabidopsis thaliana protein kinase HIGH TEMPERATURE 1 (HT1) is a negative regulator of [CO2 ]-induced stomatal closing and ht1-2 mutant plants do not show stomatal opening to low [CO2 ]. The protein kinase mutant ost1-3 exhibits slowed stomatal responses to CO2 . The functions of HT1 and OPEN STOMATA 1 (OST1) to changes in red, blue light or [CO2 ] were analyzed. For comparison we assayed recessive ca1ca4 carbonic anhydrase double mutant plants, based on their slowed stomatal response to CO2 . Here, we report a strong impairment in ht1 in red light-induced stomatal opening whereas blue light was able to induce stomatal opening. The effects on photosynthetic performance in ht1 were restored when stomatal limitation of CO2 uptake, by control of [Ci ], was eliminated. HT1 was found to interact genetically with OST1 both during red light- and low [CO2 ]-induced stomatal opening. Analyses of ca1ca4 plants suggest that more than a low [Ci ]-dependent pathway may function in red light-induced stomatal opening. These results demonstrate that HT1 is essential for red light-induced stomatal opening and interacts genetically with OST1 during stomatal responses to red light and altered [CO2 ].


Arabidopsis thaliana; HIGH TEMPERATURE 1 (HT1); OPEN STOMATA 1 (OST1); low [CO2]; photosynthesis; red light; stomata

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center