What does the RuBisCO activity tell us about a C 3 -CAM plant?

Autor: Gonçalves AZ; Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil. Electronic address: zangirolame@gmail.com., Latansio S; Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil., Detmann KC; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil., Marabesi MA; Departamento de Biologia Vegetal, Universidade de Campinas, Campinas, SP, Brazil., Neto AAC; Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil., Aidar MPM; Instituto de Botânica de São Paulo, Secretaria do Meio Ambiente, São Paulo, SP, Brazil., DaMatta FM; Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil., Mercier H; Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
Jazyk: angličtina
Zdroj: Plant physiology and biochemistry : PPB [Plant Physiol Biochem] 2020 Feb; Vol. 147, pp. 172-180. Date of Electronic Publication: 2019 Dec 17.
DOI: 10.1016/j.plaphy.2019.12.020
Abstrakt: Plants that perform the Crassulacean acid metabolism (CAM), which obtain CO 2 overnight and convert it mainly in malic acid, successfully grow in environments with water and nutrient shortages, that is partly associated with their higher water- and nitrogen-use efficiencies. Water and nutrient limitations can impair photosynthesis through the reduction of RuBisCO and increment of photorespiration, disturbing the plant carbon balance. In this context, we conducted a controlled experiment with the epiphytic C 3 -CAM bromeliad Guzmania monostachia to investigate how the combined water and nutritional deficits affect the activity of RuBisCO and its activation state (RAS), and to evaluate the efficiency of photosynthesis during the transition from C 3 to CAM. Apart from an increase in CAM activity, bromeliads submitted to both water and nutritional deficits showed higher RAS values and unaltered RuBisCO activity compared to C 3 bromeliads and, surprisingly, the maximum quantum efficiency of photosynthesis increased. Glucose, fructose and starch levels were maintained, while sucrose concentrations increased over time. These results, combined with the high RAS values, suggest an increased efficiency of RuBisCO functioning. Our results reinforce the ability of epiphytic bromeliads to deal with stressful habitats by a higher efficiency of RuBisCO during the transition to CAM, another feature that may allow their evolution in the epiphytic environment.
Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2019 Elsevier Masson SAS. All rights reserved.)
Databáze: MEDLINE
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