scholarly journals Stomatal Response to Evaporative Demand Depending on Air Humidity and Wind

2004 ◽  
Vol 42 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Daisuke YASUTAKE ◽  
Masaharu KITANO ◽  
Michio HAMAKOGA ◽  
Kota HIDAKA ◽  
Toshio KAWANO ◽  
...  
Keyword(s):  
Stomatal Response ◽  
Air Humidity ◽  
Evaporative Demand

scholarly journals The contribution of PIP2-type aquaporins to photosynthetic response to increased vapour pressure deficit

2021 ◽  
Author(s):  
D Israel ◽  
S Khan ◽  
C R Warren ◽  
J J Zwiazek ◽  
T M Robson
Keyword(s):  
Vapour Pressure Deficit ◽  
Air Humidity ◽  
Wild Type ◽  
Knockout Mutant ◽  
Evaporative Demand ◽  
Co2 Transport ◽  
Whole Plant ◽  
Knockout Mutants ◽  
Leaf Level ◽  
Low Humidity

Abstract The roles of different plasma membrane aquaporins (PIPs) in leaf-level gas exchange of Arabidopsis thaliana were examined using knockout mutants. Since multiple Arabidopsis PIPs are implicated in CO2 transport across cell membranes, we focused on identifying the effects of the knockout mutations on photosynthesis, and whether they are mediated through the control of stomatal conductance of water vapour (gs), mesophyll conductance of CO2 (gm) or both. We grew Arabidopsis plants in low and high humidity environments and found that the contribution of PIPs to gs was larger under low air humidity when the evaporative demand was high, whereas any effect of lacking PIP function was minimal under higher humidity. The pip2;4 knockout mutant had 44% higher gs than the wild type plants under low humidity, which in turn resulted in an increased net photosynthetic rate (Anet). We also observed a 23% increase in whole-plant transpiration (E) for this knockout mutant. The lack of functional AtPIP2;5 did not affect gs or E, but resulted in homeostasis of gm despite changes of humidity, indicating a possible role in regulating CO2 membrane permeability. CO2 transport measurements in yeast expressing AtPIP2;5 confirmed that this aquaporin is indeed permeable to CO2.

A reflexion on the environmental effect on the transmission of COVID-19

2021 ◽  
Author(s):  
Victor L Barradas ◽  
Monica Ballinas
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Low Temperatures ◽  
Minimum Distance ◽  
Vapor Pressure Deficit ◽  
Environmental Parameters ◽  
Air Humidity ◽  
Evaporative Demand ◽  
Small Water ◽  
The Hours

<p>This research is a general reflection of the possible transmission not only of COVID-19 but of any influenza disease depending on environmental parameters such as solar radiation, air humidity and air temperature (vapor pressure deficit), evoking the Penman-Monteith model regarding the evaporation of the water that constitutes the small water droplets (aerosols) that carry the virus. In this case the evapotranspiration demand of the atmosphere with which it can be deduced that the spread of the disease will be higher in those places with less evaporative demand, that is, high air humidity and / or low temperatures, and / or low radiation intensities, and vice versa. It can also be deduced that the hours of greatest potential contagion are the night hours, while those with the lowest risk are between 2:00 p.m. and 4:00 p.m. On the other hand, in those rooms with low temperatures the contagion would be more effective. So, considering that the drops produced by a sneeze, by speaking or breathing can go beyond two meters away, it is roughly explained that the use of face masks and keeping a safe minimum distance of two meters can limit transmission of viruses and / or infections. However, this practice is not entirely safe as the environment can play an important role. What is recommended to reduce the spread of these pathogens is to produce high evaporative demands: increasing solar radiation, and increasing air temperature and reducing air humidity, which is practice that can be effective in closed rooms.</p>

Spatial heterogeneity in stomatal features during leaf elongation: an analysis using Rosa hybrida

2015 ◽  
Vol 42 (8) ◽  
pp. 737 ◽  
Author(s):  
Dimitrios Fanourakis ◽  
Ep Heuvelink ◽  
Susana M. P. Carvalho
Keyword(s):  
Stomatal Density ◽  
Rosa Hybrida ◽  
Air Humidity ◽  
Leaf Elongation ◽  
Evaporative Demand ◽  
Mature Leaves ◽  
Relative Air Humidity ◽  
Promotive Effect ◽  
Leaf Variation ◽  
Final Length

Within-leaf heterogeneity in stomatal traits poses a key uncertainty in determining a representative value for the whole leaf. Accounting for this heterogeneity, we studied stomatal initiation on expanding leaves and estimated stomatal conductance (gs) of mature leaves. The entire lamina was evaluated at four percentages of full leaflet elongation (FLE; leaflet length relative to its final length) in Rosa hybrida L. plants grown at 60% relative air humidity (RH), and at 100% FLE following cultivation at elevated (95%) RH. Over 80% of the stomata were initiated between 33 and 67% FLE, whereas stomatal growth mostly occurred afterwards. At 100% FLE, the heterogeneity in stomatal density was the result of uneven stomatal differentiation, while an uneven differentiation of epidermal cells contributed to this variation only at elevated RH. Noticeable within-leaf differences (up to 40%) in gs were calculated at 100% FLE. Avoiding leaflet periphery decreased this heterogeneity. Despite the large promotive effect of elevated RH on stomatal and pore dimensions, the within-leaf variation remained unaffected in all characters, besides pore aperture (and, thus, gs). The noted level of within-leaf variation in stomatal features demands a sampling scheme tailored to the leaf developmental stage, the feature per se and the evaporative demand during growth.

scholarly journals Stomatal response of an anisohydric grapevine cultivar to evaporative demand, available soil moisture and abscisic acid

2011 ◽  
Vol 32 (3) ◽  
pp. 249-261 ◽  
Author(s):  
S. Y. Rogiers ◽  
D. H. Greer ◽  
J. M. Hatfield ◽  
R. J. Hutton ◽  
S. J. Clarke ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Soil Moisture ◽  
Stomatal Response ◽  
Evaporative Demand ◽  
Grapevine Cultivar ◽  
Available Soil Moisture

Stomatal response to air humidity and its relation to stomatal density in a wide range of warm climate species

1985 ◽  
Vol 7 (2) ◽  
pp. 137-149 ◽  
Author(s):  
Mabrouk A. El-Sharkawy ◽  
James H. Cock ◽  
Ana Del Pilar Hernandez
Keyword(s):  
Stomatal Density ◽  
Stomatal Response ◽  
Air Humidity ◽  
Warm Climate ◽  
Wide Range
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