24-epibrassinolide and 20-hydroxyecdysone affect photosynthesis differently in maize and spinach.
The aim of the work was to examine the effect of brassinosteroid (24-epibrassinolide; 24E) and ecdysteroid (20-hydroxyecdysone; 20E) on various parts of primary photosynthetic processes in maize and spinach. Additionally, the effect of steroids on gaseous exchange, pigment content and biomass accumulation was studied. The efficiency of the photosynthetic whole electron-transport chain responded negatively to the 24E or 20E treatment in both species, but there were interspecific differences regarding Photosystem (PS) II response. A positive effect on its oxygen-evolving complex and a slightly better energetical connectivity between PSII units were observed in maize whereas the opposite was true for spinach. The size of the pool of the PSI end electron acceptors was usually diminished due to 24E or 20E treatment. The treatment of plants with 24E or 20E applied individually positively influenced the content of photosynthetic pigments in maize (not in spinach). On the other hand, it did not affect gaseous exchange in maize but resulted in its reduction in spinach. Plants treated with combination of both steroids mostly did not significantly differ from the control plants. We have demonstrated for the first time that 20E applied in low (10nM) concentration can affect various parts of photosynthetic processes similarly to 24E and that brassinosteroids regulate not only PSII but also other parts of the photosynthetic electron transport chain - but not necessarily in the same way.
Charles University in Prague, Faculty of Science, Department of Genetics and Microbiology, Viničná 5, 128 43 Prague 2, Czech Republic.
Olga
O
Rothová
Charles University in Prague, Faculty of Science, Department of Genetics and Microbiology, Viničná 5, 128 43 Prague 2, Czech Republic. Electronic address: danahola@natur.cuni.cz.
Dana
D
Holá
Charles University in Prague, Faculty of Science, Department of Genetics and Microbiology, Viničná 5, 128 43 Prague 2, Czech Republic.
Marie
M
Kočová
Charles University in Prague, Faculty of Science, Department of Genetics and Microbiology, Viničná 5, 128 43 Prague 2, Czech Republic.
Lenka
L
Tůmová
Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Botany and Plant Physiology, Kamýcká 129, 165 21 Prague 6, Czech Republic.
František
F
Hnilička
Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Botany and Plant Physiology, Kamýcká 129, 165 21 Prague 6, Czech Republic.
Helena
H
Hniličková
Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technická 5, 166 28 Prague 6, Czech Republic.
Marek
M
Kamlar
Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technická 5, 166 28 Prague 6, Czech Republic.
Tomáš
T
Macek
D060406:Brassinosteroids / Q000008:administration & dosage; D004441:Ecdysterone / Q000008:administration & dosage; D010084:Oxidation-Reduction; D010788:Photosynthesis / Q000187:drug effects* / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000187:drug effects* / Q000235:genetics; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis; D018724:Spinacia oleracea / Q000187:drug effects* / Q000254:growth & development; D013260:Steroids, Heterocyclic / Q000008:administration & dosage; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development
D060406:Brassinosteroids; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D013260:Steroids, Heterocyclic; D004441:Ecdysterone; C023623:brassinolide
Brassinosteroids; Chlorophyll; Ecdysteroids; Gas exchange; OJIP analysis; Photosynthetic electron transport