Theoretical analysis of the CO(2) assimilation and water loss by single leaves suggests that the water use efficiency of C(4) species decreases as stomatal resistance increases. To confirm this hypothesis for a complete maize crop, results from computer simulations and a field experiment were compiled for varying stomatal resistances. A soil-plant-atmosphere model allowed simulations of the man...

Oscillations in stomatal resistance to viscous air flow have been recorded in the juvenile and adult sclerophylls of Eucalyptus umbra R. T. Baker, in both controlled and natural environments. Under constant illumination, temperature, and humidity, irregular oscillations in stomatal resistance with a periodicity of approximately 20 to 30 minutes occurred spontaneously, when the soil water potent...

BACKGROUND AND AIMS Micro-morphological characteristics can influence fungal infectivity. We sought links between micro-morphology and resistance to powdery mildew in mulberry with the intention of assisting selection of disease-resistant lines. METHODOLOGY Over 3 years and under field conditions, we evaluated 30 lines of mulberry with contrasting susceptibilities to powdery mildew (15 resist...

A parameterization scheme for calculating gaseous dry deposition velocities in air-quality models is revised based on recent study results on non-stomatal uptake of O3 and SO2 over 5 different vegetation types. Non-stomatal resistance, which includes in-canopy aerodynamic, soil and cuticle resistances, for SO2 and O3 is parameterized as a function of friction velocity, relative humidity, leaf a...

Stomata play an important role in plant innate immunity by limiting pathogen entry into leaves but molecular mechanisms regulating stomatal closure upon pathogen perception are not well understood. Here we show that the Arabidopsis thaliana L-type lectin receptor kinase-V.5 (LecRK-V.5) negatively regulates stomatal immunity. Loss of LecRK-V.5 function increased resistance to surface inoculation...

In the past, relations of diffusive resistance to stomatal geometry have concerned circular pores or pores that are replaced by equivalent circles of the same area. We calculated the resistance for general shapes that include the realistic slit. The resistance comprises two terms. The first is an outer resistance that depends only on ventilation and leaf geometry and is independent of stomata. ...

Stomatal dysfunction known as "locking" has been linked to the elicitation of a hypersensitive response (HR) following attack of fungal pathogens in cereals. We here assess how spatial and temporal patterns of different resistance mechanisms, such as HR and penetration resistance influence stomatal and photosynthetic parameters in oat (Avena sativa) and the possible involvement of hydrogen pero...

Cycloheximide was shown to block abscisic acid (ABA) biosynthesis in nonstressed as well as in stressed Phaseolus vulgaris leaves. Leaf wilting caused by cycloheximide resulted from increased stomatal opening as judged by a decreased stomatal diffusion resistance. The inhibition of ABA biosynthesis by cycloheximide was at least partially responsible for the increase in stomatal opening as sugge...

Advanced lines of Pima cotton {Gossypium barbadense L.) bred for higher yield potential and heat resistance have higher stomatal conductance and smaller leaf areas than those of obsolete !ines. In controlled experiments, five commercial lines of Pima cotton having increasing lint yield and heat resistance showed a gradient of increasing stomatal conductance and decreasing leaf size. In field ex...

abstract low water holding capacity of soilless substrates increases water stress and waste of nutrient solution. irrigation time management can reduce such problems. in this research, responses of hydroponically cultured greenhouse strawberries were evaluated under different irrigation schedules. in first step, plant daily water need was estimated and then delivered to plants through two metho...