[Dynamic change of ATPase activity on amyloplasts and protein bodies during the endosperm development in rice (Oryza...

The ultracytochemical localizations of ATPase activity on amyloplasts and protein bodies were studied by using a lead precipitation technique at middle and late developmental stage of endosperm in rice (Oryza sativa L. cv. Minghui 63). The results showed that the inner and outer plasma membrane of amyloplasts, the web-like passages among starch grains and the amorphous substance surrounding the amyloplasts exhibited high ATPase activity. ATPase activity products were present on the membranes of protein body I and protein body II, and on the vacuoles and vesicle-like structures surrounding protein bodies. Active products of ATPase were also located on the plasma membrane and cell wall of starchy endosperm cells, on the cell wall, plasma membrane, nucleus and plasmodesma of aleurone and subaleurone layer cells. According to the distribution pattern of active products of ATPase, we infer that the web-like passage in amyloplast may be the transporting channel for nutrients flowing into the amyloplast. The ATPase on amyloplasts and protein bodies can supply the power for nutrients passing through the plasma membranes.