ABSTRACT
Photosynthesis is the process by which certain organisms, that is, plants, algae, and selected bacteria, harvest solar energy and transduce it into the chemical energy of carbohydrate. Emphasis will be placed on the potential for improvement of crop yield through change in the efficiency and/or capacity of the light-dependent photosynthetic reactions, based on examples of the adaptability and fine-tuned regulation of the photosynthetic light reactions. All plants and algae contain chlorophyll a, a tetrapyrrole coordinated by magnesium in a ring structure. Several investigators have examined the flexibility of the photosynthetic unit size, utilizing two basic approaches: environmental adaptation to light intensity and the use of chlorophyll-deficient mutants. The most frequently cited argument for the lack of correlation between light reaction capacity and crop yield is in studies of chl content. Christy and Porter studied the relationship between canopy photosynthesis and yield in field-grown soybeans and found that grain yield strongly depended on seasonal photosynthesis.
