缺磷条件下玉米根系酸性磷酸酶活性的变化

Acid Phosphatase Activities of Intact Roots and Ground Root Tissues of Maize Grown in High P or Low P Nutrient Solution

在水培条件下研究了玉米根系酸性磷酸酶的活性与磷营养的关系。结果表明 :1从根尖到根基 ,根组织内的酸性磷酸酶活性逐渐降低 ,生理代谢最旺盛的根尖部其酸性磷酸酶的活性也最高 ;2根尖部酸性磷酸酶的活性不随介质磷供应水平的变化而改变 ,但在根的基部和中部较老的部位 ,其组织内酸性磷酸酶的活性在低磷供应条件下明显高于高磷处理 ;3玉米根系分泌的和根表皮细胞质外体的酸性磷酸酶活性沿根轴从根尖到根基也呈递减趋势 ,但并不随介质中磷浓度的降低而提高。这意味着根系分泌及根质外体的酸性磷酸酶是否能作为玉米磷高效的生理基础之一 ?

Acid phosphatase (Apase) activities of intact roots and ground root tissues of maize grown in high P or low P nutrient solution were studied The results showed that Apase acitvity in ground root tissue de creased from root tip to root base; Apase activities in base and middle root region were influenced by media P levels, they decreased with the increasing of media P concentration, but it was not the case in root tip region In the case of intact root regions, Apase activities along root axis from tip to base showed similar changing trend as it in ground tissue did, but Apase activities of intact roots were not influenced by P levels From the results obtained in this study, it can not be concluded the Apase root secreted and in root apoplast (i e Apase of intact root) is useful in improving maize organic P acquisition efficiency under P stress condition Whether Apase in root tissue is involved in P remobilization in maize plant is not certain, it still needs more work to test