REGULATION OF PHOTOSYNTHESIS IN LEAVES OF C-4 PLANTS FOLLOWING A TRANSITION FROM HIGH TO LOW LIGHT

作     者：DONCASTER, HD ADCOCK, MD LEEGOOD, RC 

作者机构：UNIV SHEFFIELD PHOTOSYNTH RES INST SHEFFIELD S10 2TN S YORKSHIRE ENGLAND UNIV SHEFFIELD DEPT PLANT SCI SHEFFIELD S10 2TN S YORKSHIRE ENGLAND 

出 版 物：《BIOCHIMICA ET BIOPHYSICA ACTA》 (Biochim. Biophys. Acta Bioenerg.)

年 卷 期：1989年第973卷第2期

页      面：176-184页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：Agricultural and Food Research Council, (AG50/67) European Economic Community, (ST2J-0339-C) Science and Engineering Research Council, SERC, (GR/D02577) 

主　　题：Carbon assimilation Chlorophyll fluorescence Photosynthesis, C4 (Zea) (Amaranthus) (Leaf) PGA glycerate-3- P RuBP ribulose-l,5-bisphosphate FBP fructose-l,6-bisphosphate PEP phosphor enol pyruvate G6P glucose-6-phosphate F6P fmctose-6-phosphate F o fluorescence level when all Photosystem II centres are open F m fluorescence yield when all centres are closed q Q photochemical fluorescence quenching q NP non-photochemical fluorescence quenching PFD photon flux density 

摘      要：The aim of this work was to investigate the factors which regulate photosynthetic carbon assimilation in leaves of maize (Zea mays) and Amaranthus edulis following a decrease in photon flux density. The principal observations in maize were that, after a decrease in photon flux density;(i) there were a transient inhibition of the rate of carbon assimilation;(ii) the pool of phosphoenol pyruvate rose while the flux decreased, indicating rapid regulation of the activity of phosphoenolpyruvate carboxylase;(iii) the triose-P/glycerate-3-P ratio declined drastically;at the same time the pool of pyruvate increased several-fold;(iv) the activation state of NADP+-malate dehydrogenase declined rapidly, while the activation states of pyruvate, P1 dikinase, fructose-1,6-bisphosphatase and sucrose phosphate synthase changed relatively slowly;(v) there was a rapid decrease in non-photochemical quenching of chlorophyll fluorescence and a rapid oxidation and re-reduction of QA followed by a slow oxidation of QA;(vi) in A. edulis the content of aspartate and of the total pool of C4-cycle intermediates increased. The observations are discussed in terms of the regulation of C4 photosynthesis and in terms of the supply of, and demand for, the products of electron transport by carbon metabolism. It is suggested that the transient inhibition of photosynthetic carbon assimilation in maize leaves is accompanied by a high demand for ATP which is met by cyclic electron transport.