Daily changes in VPD during leaf development in high air humidity increase the stomatal responsiveness to darkness and dry air.
Previous studies have shown that plants developed under high relative air humidity (RH>85%) develop malfunctioning stomata and therefor have increased transpiration and reduced desiccation tolerance when transferred to lower RH conditions and darkness. In this study, plants developed at high RH were exposed to daily VPD fluctuations created by changes in temperature and/or RH to evaluate the potential improvements in stomatal functioning. Daily periods with an 11°C temperature increase and consequently a VPD increase (vpd: 0.36-2.37KPa) reduced the stomatal apertures and improved the stomatal functionality and desiccation tolerance of the rosette plant Arabidopsis thaliana. A similar experiment was performed with only a 4°C temperature increase and/or a RH decrease on tomato. The results showed that a daily change in VPD (vpd: 0.36-1.43KPa) also resulted in improved stomatal responsiveness and decreased water usage during growth. In tomato, the most effective treatment to increase the stomatal responsiveness to darkness as a signal for closure was daily changes in RH without a temperature increase.
Norwegian University of Life Sciences, Department of Plant Sciences, P.O. Box 5003, 1432 Aas, Norway. Electronic address: louiar@nmbu.no.
Louise E
LE
Arve
Norwegian University of Life Sciences, Department of Mathematical Sciences and Technology, P.O. Box 5003, 1432 Aas, Norway. Electronic address: ole.kruse@nmbu.no.
Ole Mathis Opstad
OM
Kruse
University of Saskatchewan, Department of Plant Sciences, Saskatoon, SK S7N 5A8, Canada. Electronic address: karen.tanino@usask.ca.
Karen K
KK
Tanino
Norwegian University of Life Sciences, Department of Plant Sciences, P.O. Box 5003, 1432 Aas, Norway. Electronic address: jorunn.olsen@nmbu.no.
Jorunn E
JE
Olsen
Norwegian University of Life Sciences, Department of Mathematical Sciences and Technology, P.O. Box 5003, 1432 Aas, Norway. Electronic address: cecilia.futsaether@nmbu.no.
Cecilia
C
Futsæther
Norwegian University of Life Sciences, Department of Plant Sciences, P.O. Box 5003, 1432 Aas, Norway. Electronic address: sissel.torre@nmbu.no.
Sissel
S
Torre
D000388:Air; D017360:Arabidopsis / Q000502:physiology*; D003624:Darkness; D003890:Desiccation; D006813:Humidity; D018551:Solanum lycopersicum / Q000502:physiology*; D054046:Plant Stomata / Q000502:physiology*; D013696:Temperature; D055548:Vapor Pressure; D014867:Water
D014867:Water
Air humidity; Arabidopsis thaliana; Desiccation tolerance; Stomata; Tomato; VPD