THE CHANGES OF SOME ORGANELLES OCCURRED IN THE EARLY DEVELOPMENTAL STAGES OF THE MESOPHYLL PROTOPLASTS OF ASTRAGALUS MELILOTOIDES VAR. TENUIS
Li Xi-wen An Li-jia Huang Bai-qu Hao Shui (Institute of Genetics and Cytology, Northeast Normal University. Changchun 130024)
Dramatic changes of some organelles were observed during the early developmental stages of mesophyll protoplasts from A. melilotoides var. tennis. After 4 h in culture, the number of cristae and the quantity of matrix in mitochondria began to increase. A more than 5-fold increase in the number of mitochondria was reached after 3-5 days in culture, and the mitochondria-were mainly distributed around the cell nucleus. In 24 h protoplasts, the Golgi bodies, which were located at the periphery of cytoplasm, began to develop. The cytochemical staining specific to poly-saccharide showed that massive silverophi-lic material was accumulated within Golgi bodies. After l day in culture, the rough endoplasmic reticulum (RER) has remarkably increased in quantity. In addition, proplastids were seen "in a number of protoplasts at day 3. In chloroplasts of 3 day protoplasts, many cavities occurred at their peripheries. The starch grains became conspicuous in chloroplasts when the inner membrane structures were disorganized, and the chloroplasts began to turn into amyloplasts. Problems of the functions of structural changes of mitochondria, endoplasmic reticulum, Golgi bodies and chloroplasts in protoplast development were discussed in this paper.