title: Stomatal Blue Light Response Is Present in Early Vascular Plants.
abstract: Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K(+) accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum.
authors: Faculty of Art and Science, Kyushu University, Fukuoka 819-0395, Japan (M.D.); andDepartment of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan (Y.K., K.S.).
authors: Michio
authors: http://orcid.org/0000-0002-0537-7304
authors: M
authors: Doi
authors: Faculty of Art and Science, Kyushu University, Fukuoka 819-0395, Japan (M.D.); andDepartment of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan (Y.K., K.S.).
authors: Yuki
authors: Y
authors: Kitagawa
authors: Faculty of Art and Science, Kyushu University, Fukuoka 819-0395, Japan (M.D.); andDepartment of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan (Y.K., K.S.) kenrcb@kyushu-u.org.
authors: Ken-ichiro
authors: http://orcid.org/0000-0001-6450-8506
authors: K
authors: Shimazaki
mesh_terms: D017360:Arabidopsis / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D032462:Cycadopsida / Q000502:physiology*; D029624:Ferns / Q000502:physiology; D008027:Light; D019684:Magnoliopsida / Q000502:physiology*; D054046:Plant Stomata / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D006180:Proton-Translocating ATPases; D011188:Potassium