The contribution of weak CAM to the photosynthetic metabolic activities of a bromeliad species under water deficit

Autor(es)

Pikart, Filipe C. ^{[1, 2]} ; Marabesi, Mauro A. ^[3] ; Mioto, Paulo T. ^{[1, 4]} ; Goncalves, Ana Z. ^[1] ; Matiz, Alejandra ^[1] ; Alves, Frederico R. R. ^{[1, 5]} ; Mercier, Helenice ^[1] ; Aidar, Marcos P. M. ^[3]

Afiliação do(s) autor(es)

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

^[2] Univ Estadual Campinas, Inst Biol, Dept Biol Vegetal, CP 6109, BR-13083970 Campinas, SP - Brazil

^[3] Inst Bot, Nucleo Pesquisa Fisiol & Bioquim, CP 3005, BR-01061970 Sao Paulo - Brazil

^[4] Univ Fed Santa Catarina, Ctr Ciencias Biol, Dept Bot, Campus Reitor Joao David Ferreira Lima S-N, BR-88040900 Florianopolis, SC - Brazil

^[5] Univ Fed Goias, Inst Ciencias Biol, Dept Bot, Lab Fisiol Vegetal, Ave Esperanca S-N, Campus Samambaia, BR-74690900 Goiania, Go - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Plant Physiology and Biochemistry; v. 123, p. 297-303, FEB 2018.
• Citações Web of Science: 1

Resumo

The Crassulacean acid metabolism (CAM) can be a transitory strategy for saving water during unfavourable conditions, like a dry season. In some cases, CAM can also contribute to the maintenance of photosynthetic integrity, even if carbon gain and growth are impaired. CAM occurs in different intensities, being stronger or weaker depending on the degree of nocturnal malic acid accumulation. For example, Guzmania monostachia is an epiphytic tank bromeliad that shows an increase in its nocturnal organic add accumulation and a variable CAM behaviour when exposed to water deficit. In this context, this study aimed at investigating whether the weak CAM displayed by this species may mitigate the harmful effects of water limitation on its photosynthetic activity. To this, bromeliads were submitted to well-watered and water deficit conditions. Guzinattia monostachia plants under water deficiency conditions showed a reduction on atmospheric carbon assimilation without exhibiting changes in PSII integrity and carbohydrate production while showed an increase in nocturnal malic acid accumulation. Additionally, spots with high PSII efficiency in the leaf portion with a greater nocturnal malic acid accumulation were observed in plants exposed to water shortage conditions. These high-efficiency spots might be associated with a greater malate decarboxylation capacity. Also, the malic acid contributed to approximately 50% of the total carbon assimilated under water deficit. These results suggest that weak CAM may participate in photo-protection and it appears to meaningfully contribute to the overall carbon balance, being an important metabolic strategy to maintain plant fitness during water deficit periods. (AU)

• 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
• Processo FAPESP: 16/04924-0 - Manipulação dos níveis de fitocromos e seus impactos sobre o desenvolvimento plastidial, fisiologia e composição nutricional de frutos de tomateiro (Solanum lycopersicum L.)
• Beneficiário: Frederico Rocha Rodrigues Alves
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• 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: 13/15108-1 - Biossíntese, transporte e modo de ação do óxido nítrico durante a indução do Metabolismo Ácido Crassuláceo (CAM) em Guzmania monostachia.
• Beneficiário: Paulo Tamaso Mioto
• Modalidade de apoio: Bolsas no Brasil - Doutorado