Ultrastructure comparison of skins cell and leaf photosynthetic cell in tomato

By the application of electron microscope,this study made a comparison between the ultra-structures of tomato skin and of ptotosynthetic cells in leaves of mature tomatoes and measured chlorophyll content of tomato skin at different growth stages.The results showed that changes of chloroplast structure and the chlorophyll content of tomato skin cells varied across stages.The chlorophyll content of tomato skin was the highest at green ripe stage.There were some chloroplasts in several layers pericarp and there were typical structure of grana lamella.According to the theory of nearest transportation of plant photosynthate,the photosynthate produced by chloroplast in the mature-green fruit was timely transformed to fruit for its growth and development.The tomato leaves were the main organs of photosynthesis,because the numbers of chloroplast and granum-thylakoid staeks,and the chlorophyll content were obviously less than those of mesophyll cell.When the tomato was completely ripe,its color changed from green to red and all the chloroplast in flesh cells was turned into chromoplast.Meantime,the thylakoid gradually disappeared,a large amount of heavily strained grains appeared and the fruit lost its photosynthetic capacity.