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

Autor(es)

Goncalves, Ana Z. ^[1] ; Latsanio, Sabrina ^[1] ; Detmann, Kelly C. ^[2] ; Marabesi, Mauro A. ^[3] ; Neto, Antonio A. C. ^[1] ; Aidar, Marcos P. M. ^[4] ; DaMatta, Fabio M. ^[2] ; Mercier, Helenice ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Dept Bot, Rua Matao 277, BR-05508090 Sao Paulo, SP - Brazil

^[2] Univ Fed Vicosa, Dept Biol Vegetal, Vicosa, MG - Brazil

^[3] Univ Estadual Campinas, Dept Biol Vegetal, Campinas, SP - Brazil

^[4] Inst Bot Sao Paulo, Secretaria Meio Ambiente, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Plant Physiology and Biochemistry; v. 147, p. 172-180, FEB 2020.
• Citações Web of Science: 0

Resumo

Plants that perform the Crassulacean acid metabolism (CAM), which obtain CO2 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. (AU)

• Processo FAPESP: 16/09699-5 - Metabolismo do nitrogênio e sua interação com o metabolismo ácido das crassuláceas (CAM) em Guzmania monostachia (Bromeliaceae): uma abordagem fisiológica e molecular
• Beneficiário: Ana Zangirólame Gonçalves
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/12667-3 - Explorando aspectos fisiológicos e moleculares em Guzmania monostachia (Bromeliaceae): estudo das vias funcionais da fotossíntese e de resposta a nutrientes.
• Beneficiário: Helenice Mercier
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/50637-0 - Competência para a expressão do metabolismo ácido das crassuláceas (CAM) em bromélia epífita: sinalização, modulação da expressão, perfil transcricional e interação com o metabolismo de nitrogênio
• Beneficiário: Helenice Mercier
• Modalidade de apoio: Auxílio à Pesquisa - Temático