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

Author(s)

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]

Affiliation

^[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

• Document type: Journal article
• Source: Plant Physiology and Biochemistry; v. 123, p. 297-303, FEB 2018.
• Web of Science Citations: 1

Abstract

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)

• FAPESP's process: 11/50637-0 - Competence for Crassulacean Acid Metabolism (CAM) expression in epiphytic bromeliad: signaling, modulation of expression, transcriptional profile and interaction with the nitrogen metabolism
• Grantee: Helenice Mercier
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/04924-0 - Manipulating phytochrome levels in tomato fruits (Solanum lycopersicum L.) and its impacts on plastid development, physiology and nutritional composition
• Grantee: Frederico Rocha Rodrigues Alves
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/09699-5 - Nitrogen metabolism and its interaction with the Crassulacean acid metabolism (CAM) in Guzmania monostachia (Bromeliaceae): a physiological and molecular approach
• Grantee: Ana Zangirólame Gonçalves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/15108-1 - Biosynthesis, transport and mechanism of action of nitric oxide durin crassulacean acid metabolism (CAM) induction in Guzmania monostachia
• Grantee: Paulo Tamaso Mioto
• Support Opportunities: Scholarships in Brazil - Doctorate