Modelling photosynthetic responses by day and night during initial water stress in Pulmonaria vallarsae.

The relationships between photosynthesis and initial water deficit stress were investigated by chlorophyll fluorescence analysis in Pulmonaria vallarsae, a shade tolerant, perennial C3 herb by following changes of light response curves (LRCs) in single leaves during water shortage. We devised an LRC model based on two interacting rectangular hyperbolae (DH model) for the low (H1) and the high irradiance regions (H2), characterized by two parameters: maximum extrapolated ETR (V1, V2) and half-saturation irradiance (K1, K2). While H1 is assumed to represent an ETR-related function, H2 may reflect Rubisco activity.

Photosynthesis research in Italy: a review.

This historical review was compiled and edited by Giorgio Forti, whereas the other authors of the different sections are listed alphabetically after his name, below the title of the paper; they are also listed in the individual sections. This review deals with the research on photosynthesis performed in several Italian laboratories during the last 50 years; it includes research done, in collaboration, at several international laboratories, particularly USA, UK, Switzerland, Hungary, Germany, France, Finland, Denmark, and Austria. Wherever pertinent, references are provided, especially to other historical papers in Govindjee et al.

Light-harvesting complex 1 stabilizes P+QB- charge separation in reaction centers of Rhodobacter sphaeroides.

The kinetics of charge recombination following photoexcitation by a laser pulse have been analyzed in the reaction center-light harvesting complex 1 (RC-LH1) purified from the photosynthetic bacterium Rhodobacter sphaeroides. In RC-LH1 core complexes isolated from photosynthetically grown cells P(+)Q(B)(-) recombines with an average rate constant, k approximately 0.3 s(-1), more than three times smaller than that measured in RC deprived of the LH1 (k approximately 1 s(-1)).

Structural role of PufX in the dimerization of the photosynthetic core complex of Rhodobacter sphaeroides.

Monomeric and dimeric PufX-containing core complexes have been purified from membranes of wild-type Rhodobacter sphaeroides. Reconstitution of both samples by detergent removal in the presence of lipids leads to the formation of two-dimensional crystals constituted of dimeric core complexes. Two-dimensional crystals were further analyzed by cryoelectron microscopy and atomic force microscopy.