[The ultrastructures of storage protein accumulation in aleurone layer and cotyledons of Fagopyrum esculentum].
The ultrastructures of storage protein accumulation in cotyledons and aleurone layer in buckwheat (Fagopyrum esculentum Monch) were investigated by electron microscopy. (1) On 15 days after anthesis (DAA), there are many dictyosomes and vacuoles accumulating protein in cytoplasm of the outer layer endosperm cells. These cells containing abundant aleurone grains (1-2 microm in diameter) from vacuoles accumulated storage protein form aleurone layer where division of aleurone grain is also observed on 25 DAA. (2) On 20 DAA, protein begins to accumulate in vacuoles of cotyledon cells. At the early stage of protein deposition, vacuoles are becoming smaller ones by ingrowth of tonoplast or by pinch-off. A multitude of ribosomes, many dictyosomes and electron-dense vesicles (0.1-0.7 microm in diameter) coated with membrane are observed in cytoplasm of cotyledon cells at every stage of protein accumulation. Originated from the separation of saccules containing protein at the fringe of dictyosome, these vesicles (0.1-0.2 microm in diameter) probably increase their volume by fusion each other. They play the leading role in transporting storage protein into vacuoles that become PSVs in cotyledon cells of buckwheat. On 25 DAA, there are many PSVs (1-3 microm in diameter) and some vesicles (0.1-0.7 microm) filled with protein in mature cotyledon cells. These vesicles may be also play a part in accumulating storage protein in mature buckwheat seed.
Gao
Xin Qi
XQ
Department of Biology, Qufu Normal University, Shandong Qufu 273165.
Wang
Xiu Ling
XL
Xi
Xiang Yuan
XY
D018548:Cotyledon / Q000378:metabolism* / Q000648:ultrastructure; D019612:Fagopyrum / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010940:Plant Proteins / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism / Q000648:ultrastructure
D010940:Plant Proteins