Leaf metabolites, adenylates, and Rubisco activation were studied in two transgenic tobacco (Nicotiana tabacum L. cv W38) types. Plants with reduced amounts of cytochrome b/f complex (anti-b/f) have impaired electron transport and a low transthylakoid pH gradient that restrict ATP and NADPH synthesis. Plants with reduced glyceraldehyde 3-phosphate dehydrogenase (anti-GAPDH) have a decreased cap...

Photorespiration is one of the most intensively studied topics in plant biology. While a number of mutants deficient in photorespiratory enzymes have been identified and characterized for their physiological functions, efforts on glycolate oxidase (GLO; EC 1.1.3.15) have not been so successful. This is a report about the generation of transgenic rice (Oryza sativa L.) plants carrying a GLO anti...

Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) is responsible for the fixation of atmospheric CO2 in photosynthesis. Rubisco is not only the most abundant protein in nature but also one with a remarkably high chaperone requirement for folding, assembly and maintenance. The major form of Rubisco (form I) is hexadecameric, consisting of 8 large (RbcL) and 8 small (RbcS) subunits. The f...

Inhibition of the net photosynthetic CO 2 assimilation rate ( P n ) by high temperature was examined in oak ( Quercus pubescens L.) leaves grown under natural conditions. Combined measurements of gas exchange and chlorophyll (Chl) a fluorescence were employed to differentiate between inhibition originating from heat effects on components of the thylakoid membranes and that resulting from effect...

During catalysis, all Rubisco (D-ribulose-1,5-bisphosphate carboxylase/oxygenase) enzymes produce traces of several by-products. Some of these by-products are released slowly from the active site of Rubisco from higher plants, thus progressively inhibiting turnover. Prompted by observations that Form I Rubisco enzymes from cyanobacteria and red algae, and the Form II Rubisco enzyme from bacteri...