Effects-of Zinc and Copper on Activity of Leaf Carbonic Anhydrase in Malus sp.
Dong Wenxuan and Shen Tsuin Meng Fanjing(Department of Horticulture, Beijing Agricultural University 100094) (Biology College of Beijing Agricutaral University)
The effects of zinc and copper on carbonic anhydrase (CA) activity and leaf content of Zn, Cu. P. Fe, Ca (only zinc treatments) in Malus sp. were studied. The results showed that, the leaf CA activity of the solution-cultured 'Tiancha' seedlings (M, huphensis) and young apple plants (M, pumila), treated with 0. 50 mg · l-1 zinc-containing solution was the highest; Bordeaux mixture (1: 2 : 160) added into leaf extract of apple plants obviously inhibited the CA activity, however addition of copper sulphate solution(160×) had only a little inhibition on it ; foliar spray of Bordeaux mixture (1 : 2 : 160) to one -year-old apple trees had certain inhibition effect on CA activity; Spraying zinc-containing fertilizer on bearing Starking apple trees (M. pumila) did not make significant influence on CA activity; Zinc solution culture and foliar spray at the stage of shoot rapid growing period could significantly change and/or increase leaf zinc content, but not obviously change the leaf content of Cu, P, Fe, Ca. The inter-relation between leaf zinc content and CA activity and the mechanism of CA activity inhibition induced by Bordeaux mixture were discussed.