Excitation Spillover from PSII to PSI in Leaves at 77K.

Heterogeneous distribution of PSI and PSII in thick grana in shade chloroplasts is argued to hinder spillover of chlorophyll excitations from PSII to PSI. To examine this dogma, we measured fluorescence induction at 77K at 690 nm (PSII) and 760 nm (mostly PSI) in the leaf discs of Spinacia oleracea, Cucumis sativus and shade tolerant Alocasia odora, grown at high and low light, and quantified their spillover capacities. PSI fluorescence (FI) consists of the intrinsic PSI fluorescence (FIα) and fluorescence caused by excitations spilt over from PSII (FIβ).

CO -induced chloroplast movement in one cell-layer moss leaves.

CO -induced chloroplast movement was reported in the monograph by Gustav Senn in 1908: unilateral CO supply to the one cell-layered moss leaves induced the positively CO -tactic periclinal arrangement of chloroplasts. Here, using the model moss plant Physcomitrium patens, we examined basic features of chloroplast CO -tactic relocation with a modernized experimental system. The CO relocation was light-dependent and, especially, CO relocation in red light was substantially dependent on photosynthetic activity.

A rapid and simple spectroscopic method for the determination of yeast cell viability using methylene blue.

Determination of cell viability is important in various microbiological studies. The microscopic method, counting dead cells stained by methylene blue (MB), has often been used for the determination of viability, although it is not efficient for the measurement of a large number of samples. Alternatively, some spectroscopic methods have been proposed to avoid tedious cell counting.

Elevated CO induces rapid dephosphorylation of plasma membrane H -ATPase in guard cells.

Light induces stomatal opening, which is driven by plasma membrane (PM) H -ATPase in guard cells. The activation of guard-cell PM H -ATPase is mediated by phosphorylation of the penultimate C-terminal residue, threonine. The phosphorylation is induced by photosynthesis as well as blue light photoreceptor phototropin.

Cost-benefit analysis of mesophyll conductance: diversities of anatomical, biochemical and environmental determinants.

Background: Plants invest photosynthates in construction and maintenance of their structures and functions. Such investments are considered costs. These costs are recovered by the CO2 assimilation rate (A) in the leaves, and thus A is regarded as the immediate, short-term benefit.