Meristem temperature differs from air temperatureCrop Ecology 20135-4-2013, Andreas Savvides
Temperatures Tair= 22oC HumanHomeotherm: Able tomaintain constant bodytemperature throughmetabolism.Cucumber plant Poikilotherm: Unable to maintain constant body temperature through metabolism.
Temperature & Plant LifeTemperature influences: Which• Plant metabolism: temperature? Photosynthesis Dark Respiration The temperature• Plant growth experienced by the• Plant development plant!!!
Temperature & Plant lifeThe fact that poikilotherms cannot maintain constanttemperature does not necessarily imply that their bodytemperature will always beequal to air temperature...
Meristem function and temperature TemperaturePerception ResponseMeristem Function Organogenesis
Meristem temperature differs from air temperature:depending on radiation and species 5 25 23 3 Tmeristem (oC) 21 1 19 -1 Day Night (a) 17 -3 (b) Cucumber 23 3 Tomato 15 Tmeristem (oC) -5 -100 0 100 200 300 21 1 Rnet (W m-2) -1 19
Meristem temperature differs from air temperature:depending on vapour pressure deficit and species Day Night (a) (b) Cucumber 23 3 Tomato Tmeristem (oC) 21 1 -1 19 17 -3 0.2 0.5 0.8 1.1 0.2 0.5 0.8 1.1 VPD (kPa) VPD (kPa)
Conclusions• Meristem temperature differs substantially from airtemperature depending on other environmental factors• Meristem temperature differs between species• If we are to properly estimate/model the effects of theenvironment (e.g. climate change impacts) on plantdevelopment, meristem temperatures should be quantifiedinstead of air temperature