Diversity of plant photosynthesis Photosynthesis is not only the oldest problem in biology, but also one of the frontier fields of biology at present, because it is of great practical significance not only in agriculture, energy, ecology and other issues, but also in basic biological theoretical issues such as the origin, evolution and light energy conversion of life. But since 177 1 Priestley discovered photosynthesis, the original process of photosynthesis is still unclear, but the chemical process of carbon assimilation in photosynthesis has been clearly recognized and understood. Generally speaking, green plants (especially higher plants) not only show extensive adaptability in different natural environments, but also show the diversity of photosynthesis modes. 1. Various modes of photosynthesis