玉米萌發期間子葉盤酸性磷酸酶活性之研究

Study on the Activity of Acid Phosphatase in the Scutellum of developing Maize Seedlings

吳貞瑩(Jen-Yng Wu) ； 童武夫(Wu-Fu Tong)

《師大生物學報》 19卷 (1984/10) Pp. 49-60

https://doi.org/10.29812/BBNTNU.198410.0006

摘要

玉米萌發期間子葉盤的酸性磷酸酶活性，並未隨著幼苗的生長而增高，反而有緩慢下降的趨勢。第六天幼苗子葉盤可溶性蛋白質含量急劇降低，反映了組織已開始老化。吉貝素或細胞分裂素的處理，可促進子葉盤酶活性的增高。同時也維持可溶性蛋白質含量的穩定，而延緩組織的老化。酸性磷酸酶主要存在於子葉盤組織中，祇有少量的酶活性能在離體子葉盤的漫液中測得。無論是吉貝素或細胞分裂素的處理，都不會增高酶分子的釋放。在玉米萌發期間，可觀察到五條酸性磷酸酶的異構酶帶。其中C1異構酶活性隨著幼苗的生長而增高，而C3異構酶活性則穩定地呈現於各萌發階段。根據異構酶在各萌發時期的相對活性及在電泳場中的泳動距離，推論酶分子為兩次體所組成且比五條異構酶為四類多肽的組合。利用蔗糖坡度離心法分離各次細胞部分，以確定酶活性在細胞內的分佈，其結果顯示酸性磷酸酶主要存在於細胞膠賀，祇有少量活性組合於內質網及細胞膜。

並列摘要

The physiological role of acid phosphatase in the scutellum of developing maize seedlings was investigated. From third day of the germination activity of acid phosphatase in the scutellum declined slowly with grown of seedling, and the soluble protein content decreased sharply at sixth-day scutellum which indicated the beginning of tissue senescence.Both enzyme activity and soluble protein content were increased after the seedlings had been treated with 10^(-6) M gibberellin or 10^(-5) M benzyl adenine. Only a minor fraction of enzyme activity could be observed in the incubated medium of isolated scutellum. The release of enzyme from scutellum could not be affected by addition of either gibberellin or benzyl adenine.Five isozymes of acid phosphatase were observed during development of seedling. Activity of C1 isozyme increased obviously with grown of seedling, while the activity of C3 isozym maintained the same through the developmental stages. The result of subcellular fractionation by discontinuous sucrose gradient centrifugation indicates that most activities of acid phosphatase locate in the cytosol, only a minor fraction of activity associates with endoplasmic reticulum and plasma membrane.