Graham D. Farquhar, M. H. O'leary, Joseph A. Berry
Theory is developed to explain the carbon isotopic composition of plants. It is shown how diffusion of gaseous CO2 can significantly affect carbon isotopic discrimination. The effects on discrimination by diffusion and carboxylation are integrated, yielding a simple relationship between discrimination and the ratio of the intercellular and atmospheric partial pressures of CO2. The effects ...... hiện toàn bộ
In the last decade, our understanding of the processes underlying plant response to drought, at the molecular and whole-plant levels, has rapidly progressed. Here, we review that progress. We draw attention to the perception and signalling processes (chemical and hydraulic) of water deficits. Knowledge of these processes is essential for a holistic understanding of plant resistance to stre...... hiện toàn bộ
The allocation of biomass to different plant
organs depends on species, ontogeny and on the environment experienced by the
plant. In this paper we first discuss some methodological tools to describe
and analyse the allocation of biomass. Rather than the use of shoot:root
ratios, we plead strongly for a subdivision of biomass into at least three
compartments: leaves, stems and roots. Attent...... hiện toàn bộ
Fruit softening during ripening involves a coordinated series of modifications to the polysaccharide components of the primary cell wall and middle lamella, resulting in a weakening of the structure. Degradation of polysaccharides and alterations in the bonding between polymers cause an increase in cell separation and a softening and swelling of the wall, which, combined with alterations i...... hiện toàn bộ
Jaume Flexas, Josefina Bota, José M. Escalona, Bartolomé Sampol, H. Medrano
The effect of diffusional and photochemical limitations to photosynthesis was
assessed in field-grown water-stressed grapevines
(Vitis vinifera L.) by combined measurements of gas
exchange and chlorophyll fluorescence. Drought was slowly induced, and the
progressive decline of photosynthesis was examined in different grapevine
cultivars along a continuous gradient of maximum mid-morning v...... hiện toàn bộ
An empirical model of stomatal conductance is presented. The predictions of conductance correlate with experimental determinations of the responses to several kinds of short-term and long-term perturbations, including irradiance, temperature, CO2 and O2 partial pressures, and leaf age and nitrogen nutrition. The model is not mechanistic and cannot account for the observed functioning of st...... hiện toàn bộ
The photosynthetic apparatus of plants responds to changing light quantity and quality with coordinated changes in both the light-harvesting antennae of the photosystems and the amounts of electron transport components and ATP synthase. These compositional modulations are accompanied by changes in thylakoid membrane organisation and photosynthetic capacity. It is now clear that there is a ...... hiện toàn bộ
Stomatal conductances, CO2 assimilation, transpiration and intercellular CO2 mol fractions of Eucalyptus grandis leaves were measured in the field using a portable, controlled environment cuvette. Test leaves were subjected to a range of temperatures, humidities, photon irradiances and external CO2 mol fractions. An empiral function, gsw = g0 + g1 Ahs/(cs-I'), was able to account for stead...... hiện toàn bộ
Wheat seedlings were grown in soil of various strengths, obtained by changing the bulk density or the water content of the soil. Leaf expansion and transpiration rate were monitored from emergence until the main stem had 5-7 leaves. Leaf area, and shoot and root dry weights, were negatively correlated with soil strength as measured by penetrometer resistance. The growth of roots was less a...... hiện toàn bộ