this study was carried out in order to determine the leave characteristics of some chestnut genotypes in the central black sea region of turkey and also to determine whether the leaf morphometric characteristics could be used for differentiation of genotypes. in this study, seven chestnut (castanea sativa mill.) genotypes (sa5-1, se 3-12, se 21-2, se 21-9, 552-8, 556-7 and 556-8) and one cultiv...

ROP small G proteins function as molecular switches in diverse signaling processes. Here, we investigated signals that activate ROP2 in guard cells. In guard cells of Vicia faba expressing Arabidopsis thaliana constitutively active (CA) ROP2 fused to red fluorescent protein (RFP-CA-ROP2), fluorescence localized exclusively at the plasma membrane, whereas a dominant negative version of RFP-ROP2 ...

In plants, drought stress is a major growth limiting factor causing cell water loss through open stomata. In this study, guard cell-specific transcripts from drought-stressed Arabidopsis plants were analysed and a down-regulation of β-amylase 1 (BAM1) was found. In previous studies, BAM1 was shown to be involved in stomatal starch degradation under ambient conditions. Impaired starch breakdown ...

Cercospora zeae-maydis causes gray leaf spot of maize, which has become one of the most widespread and destructive diseases of maize in the world. C. zeae-maydis infects leaves through stomata, which is predicated on the ability of the pathogen to perceive stomata and reorient growth accordingly. In this study, the discovery that light was required for C. zeae-maydis to perceive stomata and inf...

Stomata are crucial in land plant productivity and survival. In general, with lower irradiance, stomatal and epidermal cell frequency per unit leaf area decreases, whereas guard-cell length or width increases. Nevertheless, the stomatal index is accepted as remaining constant. The aim of this paper to study the influence of ordinary epidermal cells and stomata on leaf plasticity and the influen...

Lotus, Nelumbo nucifera, posses a specialised efflux organ in the centre of their leaves, which connects the gas canals in the leaves and stems with the atmosphere through the apertures of large stomata. The role of these large central plate stomata in regulating air flow through the gas canals were examined on excised leaves and on intact plants in situ. The stomata show a diurnal cycle, closi...

Stomata, flanked by pairs of guard cells, are small pores on the leaf surfaces of plants and they function to control gas exchange between plants and the atmosphere. Stomata will open when water is available to allow for the uptake of carbon dioxide for photosynthesis. During periods of drought, stomata will close to reduce desiccation stress. As such, optimal functioning of stomata will impact...

Stomatal guard cells regulate plant photosynthesis and transpiration. Central to the control of seed plant stomatal movement is the phytohormone abscisic acid (ABA); however, differences in the sensitivity of guard cells to this ubiquitous chemical have been reported across land plant lineages. Using a phylogenetic approach to investigate guard cell control, we examined the diversity of stomata...

Photosynthesis is often limited by the rate of CO(2) diffusion from the atmosphere to the chloroplast. The primary resistances for CO(2) diffusion are thought to be at the stomata and at photosynthesizing cells via a combination resulting from resistances of aqueous solution as well as the plasma membrane and both outer and inner chloroplast membranes. In contrast with stomatal resistance, the ...

Williams (6, 7) was the first to observe that epidermal strips taken from the area of leaf enclosed by an unswept porometer cup show much wider stomatal pores than elsewhere. Heath's experiments with Pelargonium and wheat (4, 5) showed that sweeping the porometer cup with dry or humid air caused considerable closure of the stomata as compared with the areas in still air. In a repetition of Knig...