It has beeni recogniized for a lolng tiiiie that the rate of absorption of CO2 by a greein plant shoot or leaf enclosed in a vessel is affected by the rate at whieh air is supplied. Much attention has been given to the problem of miaintaining a "normal" air supply; that is, a CO2 supply comiiparable to that foundl under natural conditions. The early literature was reviewed and discussed by HEIN...

It is believed that high levels of mesophyll conductance (gm) largely contribute to the high rates of photosynthesis in herbaceous C3 plants. However, some sclerophyllous C3 plants that display low levels of gm have high rates of photosynthesis, and the underlying mechanisms responsible for high photosynthetic rates in sclerophyllous C3 plants are unclear. In the present study, we examined phot...

Ribulose-1,5-bisphosphate carboxylase (Rubisco) efficiency for CO2-saturated photosynthesis was examined in leaves of rice (Oryza sativa L.). The amount of Rubisco in a leaf was calculated to be 30-55% in excess for the light-saturated rate of photosynthesis at 100 Pa CO2. Long-term exposure to CO2 enrichment decreased the amount of Rubisco protein. However, N was not reallocated from decreased...

in this study the response of 9 rapeseed genotypes were evaluated at the seedling stage using different irrigation levels (50, 70 and 100% fc). a factorial experiment based on rcbd was conducted in the research greenhouses of urmia university with four replications during summer of 2013. some physiological traits such as relative water content, stomatal conductance, transpiration, photosynthesi...

Ecophysiological characteristics of "Ahmadaghaii" "Ohadi" "Kallehghuchi" cultivars (as scions) on four pistachio rootstocks (Pistacia vera Cv. Badami riz, P. vera Cv. Sarakhs, P. atlantica sub sp. Mutica, P. atlantica sub sp. Atlantica) were evaluated during the spring and summer seasons of 2005 in the Iran's Pistachio Research Institute (IPRI). Ecophysiological characteristics such as photosyn...

Changes in photosynthesis, carbon partitioning, and growth following resupply of orthophosphate (Pi) to moderately P-deficient plants (low-P) were determined for sugar beets (Beta vulgaris L. cv F58-554H1) cultured hydroponically in growth chambers. One set of plants was supplied with 1.0 mM Pi in half-strength Hoagland solution (control plants), and a second set (low-P plants) was supplied wit...

Arabidopsis thaliana shows hybrid vigor (heterosis) in progeny of crosses between Columbia-0 and C24 accessions. Hybrid vigor was evident as early as mature seeds and in seedlings 3 d after sowing (DAS). At 3 DAS, genes encoding chloroplast-located proteins were significantly overrepresented (187) among the 724 genes that have greater than midparent values of expression in the hybrid. Many of t...

The effect of 3,3-dichloro-2-(dihydroxyphosphinoylmethyl)propenoate (DCDP), an analog of phosphoenolpyruvate (PEP), on PEP carboxylase activity in crude leaf extracts and on photosynthesis of excised leaves was examined. DCDP is an effective inhibitor of PEP carboxylase from Zea mays or Pancum miliaceum; 50% inhibition was obtained at 70 or 350 micromolar, respectively, in the presence of I mil...