Kouki Hikosaka 교수

Growth temperature alters temperature dependence of the photosynthetic rate (temperature acclimation). In many species, the optimal temperature that maximizes the photosynthetic rate increases with increasing growth temperature. In this minireview, mechanisms involved in changes in the photosynthesis-temperature curve are discussed. Based on the biochemical model of photosynthesis, change in the photosynthesis-temperature curve is attributable to four factors: intercellular CO2 concentration, ac

ABSTRACT A model of leaf photosynthesis of C 3 , plants has been developed to describe their nitrogen economy. In this model, photosynthetic proteins are categorized into five groups depending on their functions. The effects of investment of nitrogen in each of these groups on the maximal rate of photosynthesis and/or the initial slope of the light‐response curve are described as simple equations. Using this model, the optimal pattern of nitrogen partitioning which maximizes the daily rate of CO

When leaf turnover is at a steady state, the ratio of biomass production to nitrogen uptake is equal to the ratio of litter fall to nitrogen loss, which is an inverse of the nitrogen concentration in dead leaves. Thus nitrogen concentration in dead leaves (nitrogen resorption proficiency) and nitrogen availability in the soil determine the rate of photosynthesis in the canopy. Dynamics of leaves are regulated so as to maximize carbon gain and resource-use efficiency of the plant.

1. Chenopodium album (a sun species) and Alocasia macrorrhiza (a shade species) plants were grown under various photon flux densities (PFDs) to investigate whether nitrogen partitioning among photosynthetic components was optimized under any light conditions. The amounts of several photosynthetic components of the leaves were determined to examine nitrogen partitioning. 2. For the same PFD, nitrogen partitioning among photosynthetic components was similar in both species, except for leaves of C.

1. Photosynthetic characteristics of an annual herb, Chenopodium album , and an evergreen tree, Quercus myrsinaefolia , were compared to clarify causes of the difference in photosynthetic nitrogen‐use efficiency (photosynthetic capacity per unit nitrogen) between leaves of herbaceous and evergreen species. 2. When leaves with the same nitrogen content on an area basis were compared, photosynthetic capacity of C. album was twice as high as that of Q. myrsinaefolia . Gas‐exchange measurements show

Changes in the temperature dependence of the photosynthetic rate depending on growth temperature were investigated for a temperate evergreen tree, Quercus myrsinaefolia . Plants were grown at 250 μ mol quanta m –2 s –1 under two temperature conditions, 15 and 30 °C. The optimal temperature that maximizes the light‐saturated rate of photosynthesis at 350 μ L L –1 CO 2 was found to be 20–25 and 30–35 °C for leaves grown at 15 and 30 °C, respectively. We focused on two processes, carboxylation and

:To analyze the effect of leaf angle on light competition among individual plants, a simple model for photosynthesis of an individual plant in a dense stand was developed. The model assumes that each plant has a particular leaf angle that determines the light-extinction coefficient (K). Light climate of a target plant is determined by the K values both of its own and of its neighbors, while light absorption of a target is determined by its own K. Evolutionarily stable K (ESK) values (the K value

A model of dynamics of leaves and nitrogen is developed to predict the effect of environmental and ecophysiological factors on the structure and photosynthesis of a plant canopy. In the model, leaf area in the canopy increases by the production of new leaves, which is proportional to the canopy photosynthetic rate, with canopy nitrogen increasing with uptake of nitrogen from soil. Then the optimal leaf area index (LAI; leaf area per ground area) that maximizes canopy photosynthesis is calculated

Nitrogen distribution within a leaf canopy is an important determinant of canopy carbon gain. Previous theoretical studies have predicted that canopy photosynthesis is maximized when the amount of photosynthetic nitrogen is proportionally allocated to the absorbed light. However, most of such studies used a simple Beer's law for light extinction to calculate optimal distribution, and it is not known whether this holds true when direct and diffuse light are considered together. Here, using an ana