Short-term dynamics of stomatal response to sudden increase in CO₂ concentration in maize supplied with different amounts of water

Abstract

Environmental factors that influence stomatal conductance (g s ) interact through a complex network of signal transduction and have therefore highly interdependent effect.In the present study we examined how plant water status affects stomatal sensitivity to the change of CO 2 concentration ([CO 2 ]). We investigated the short-term dynamic of stomatal response to a sudden [CO 2 ] increase (from 400 to 700 µmol(CO 2 ) mol -1 ) in maize supplied with different amounts of water (resulting ψ w = -0.35, -0.52 and -0.75 MPa). Gas exchange measurements were performed in short logging intervals and the response was monitored under two different levels of water vapour pressure deficit (VPD) of 1 and 2 kPa in order to observe the impact of air humidity. Generalized logistic curves were fitted to standardized stomatal response data, which enabled us to objectively estimate the level (relative decrease of g s ) and the dynamics of the response.Soil water stress and high VPD significantly decreased relative stomatal closure in response to [CO 2 ] rise, but simultaneously accelerated stomatal response to [CO 2 ], as revealed by shorter half life (t 1/2 ). VPD significantly affected the response of well-watered plants. In contrast, a fast stomatal reaction of water-deprived plants was predetermined by a low xylem water potential (ψ w ) of the leaf and the influence of air humidity was minor.

Physiological responses to salinity in Silver buffaloberry (Shepherdia argentea) introduced to Qinghai high-cold and saline area, China

“…In addition, salinity resulted in dehydration at the cellular level, and thus significantly reduced the RWC in the leaves of S. argentea (Table 2). Hladnik et al (2009) reported that a fast stomatal reaction of water-deprived plants is predetermined by a low xylem water potential of the leaf. According to our results, the salinity-level increase progressively decreased g s in the leaves of S. argentea seedlings (Fig.…”

Analysis of dominant factors influencing moisture change of broad-ovate leaves of Populus euphratica Oliv. in extremely arid region

“…Leaf stomata control the exchange of water vapour and environmental CO 2 . Stomatal conductance (g s ) is an important parameter to describe the flux exchange between vegetation and atmosphere (Nicolás and Philippe 2009, Hladnik et al 2009, James 2004. The level of plant transpiration rate (E) can reflect plants' adaptive ability to the environment (Fung et al 1998).…”