ROS and antioxidants in Guzmania monostachia: induction of CAM is a defence strategy to alleviate oxidative stress?

• Grant number: 14/03147-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2014
• End date: October 31, 2016
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Helenice Mercier
• Grantee: Maria Elizabeth Pereira de Abreu
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 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, AP.TEM

Abstract

Reactive oxygen species (ROS) are formed in reactions to the metabolism, such as photosynthesis and respiration, and act as signalling molecules that regulate many cellular processes such as growth, development and plant's response to stress. CAM plants have the capacity to deal with highly changing environments due to the flexibility of reversible morphological and physiological adaptations to multiple stresses. However, little is known about the signalling pathway of ROS in plants with CAM metabolism; despite the knowledge that that ROS production is limited in CAM plants. This project aims to answer the following question: the induction of CAM is a defence strategy to alleviate oxidative stress? To answer this question, we consider several key hypothesis: CAM metabolism prevents the production of ROS? CAM plants show efficient antioxidant system response? NO and plant hormones interact in redox regulation during the induction of CAM? To answer these questions we use as a study object the epiphytic bromeliad, Guzmania monostachia, a species that can be induced to CAM and even reverse the condition C3, which may facilitate getting quite interesting and new results on the importance of ROS during induction CAM. It is expected that with the development of this project we would be able to discuss what are the mechanisms of redox homeostasis readjustment in CAM plants. Regulatory networks that control the production and elimination of ROS during induction of CAM, will be characterized by changes from C3 to CAM in leaves at different stages of development, from plants at different ontogenetic stages. The production of ROS as the antioxidant response system varies according to the nature and severity of the stress, as the antioxidant system response depends partly on the type of plant photosynthesis. Therefore, special attention should be granted to the importance of the antioxidant system response during the transition C3-CAM, given that the antioxidants have a crucial role in redox regulation. This project will aim to highlight the possible interactions between endogenous levels of plant hormones and ROS during the induction of CAM, since it is known that ROS signaling system is highly integrated with the signaling networks of plant hormones. The results obtained with the progress of this project will contribute to further understanding of the physiological and biochemical strategies used during the development of epiphytic thank-forming bromeliad when exposed to adverse environmental conditions. Such knowledge may be used as important biotechnological tools, since the accumulation of ROS due to environmental changes is one of the major causes of loss of crop productivity in the world.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ABREU, MARIA E.; CARVALHO, VICTORIA; MERCIER, HELENICE. Antioxidant capacity along the leaf blade of the C-3-CAM facultative bromeliad Guzmania monostachia under water deficit conditions. FUNCTIONAL PLANT BIOLOGY, v. 45, n. 6, p. 620-629, 2018. (11/50637-0, 14/03147-5)

CARVALHO, VICTORIA; ABREU, MARIA E.; MERCIER, HELENICE; NIEVOLA, CATARINA C.. Adjustments in CAM and enzymatic scavenging of H2O2 in juvenile plants of the epiphytic bromeliad Guzmania monostachia as affected by drought and rewatering. Plant Physiology and Biochemistry, v. 113, p. 32-39, APR 2017. (11/50637-0, 14/03147-5)