Effects of NO3- stress and recovery on chlorophyll fluorescence parameters and Atpase activities of cucumber seedling leaves
Yang, F.; Wang, X.; Wei, M.; Su, X.; Yan, T.
Ying Yong Sheng Tai Xue Bao 17(3): 403-407
2006
ISSN/ISBN: 1001-9332 PMID: 16724732 Document Number: 601174
With water culture, this paper studied the effects of NO3- stress and recovery on the chlorophyll contents, chlorophyll fluorescence parameters, and ATPase activities of cucumber seedling leaves. The results showed that under stress for 7 days, the chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents, intrinsic fluorescence (F-o), and Mg-ATPase and Ca-ATPase activities were increased significantly when the NO3- concentration was high (168 mmol.L-1), while the intrinsic photochemical efficiency (F-v/F-m), potential activities (F-v/F-o) and quantum yield (Phi PSII) of PSII were decreased with increasing NO3- concentration. After recovery for 7 days, the chlorophyll and carotenoid contents of all treatments with NO3- were lower than CK, while the intrinsic fluorescence, intrinsic photochemical efficiency and quantum yield of PS H were similar to CK when the NO3- concentration was <= 84 mmol.L-1, and the F-v/F-m and Phi PSII were significantly lower than CK when the NO3- concentration was > 84 mmol.L-1. The potential activity of PSII was similar to CK when the NO3- concentration was 42 and 126 mmol.L--1,L- but significantly lower than CK in other treatments. The activities of Mg-ATPase and Ca-ATPase were decreased firstly but increased then when the NO3- concentration was > 84 mmol L-1.