Taxonomy, phylogeny and influence of Zinc (Zn) and Cadmium (Cd) concentration on the morphology and ecophysiology of Desmids (Desmidiaceae, Zygnematophyceae).

• Grant number: 23/12503-9
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• Start date: September 01, 2023
• End date: August 31, 2025
• Field of knowledge: Biological Sciences - Botany - Applied Botany
• Agreement: CNPq
• Principal Investigator: Ana Teresa Lombardi
• Grantee: Camila Barbosa de Araújo
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 23/01410-0 - Taxonomy, phylogeny and influence of Zinc (Zn) and Cadmium (Cd) concentration on the morphology and ecophysiology of Desmids (Desmidiaceae, Zygnematophyceae)., AP.R

Abstract

The present proposal aims to expand the morphological and phylogenetic knowledge for isolates belonging the genus Pseudomicrasterias and Micrasterias arcuata species complex, both belonging the family Desmidiaceae (Zygnematophyceae). In addition, this proposal aims to fill the lack of information about the influence of Zinc (Zn) and Cadmium (Cd) concentration on the morphology and physiology of these individuals under culture and experimental conditions. Recent studies obtained about the phylogenetic positioning of M. arcuata isolates have shown the genetic and evolutionary distance of these individuals in relation to the Micrasterias lineage. Despite important advances, new questions have arisen regarding the influence of environmental variables and the adaptive strategies adopted by these individuals in conditions of environmental stress. Molecular biology and phylogenetic analyses, as well as morphometrics analyses will be carried out, in addition to the examination of their cell growth. Experiments will be carried out to evaluate the effects of the concentration of metals Zinc (Zn) and Cadmium (Cd) on the physiology and photosynthetic efficiency of these individuals. Even though there is no evidence that Cd has any nutritional role in microalgae, its essentiality for some organisms has been discussed. Literature show that such element can replace Zn in specific situations in diatoms, but little is known about the physiological adaptative mechanisms that vary with the tolerance for this metal in Desmids. This research will be able to answer this question and will complement it with detailed information about cell physiology. The present proposal intends to create a database subsidized by several areas of knowledge, which is essential for the knowledge of green microalgae biodiversity, a in addition to subsidizing future ecophysiological and biotechnological studies. The results of this project will be relevant for the physiological understanding of metal uptake from an evolutionary point of view due to the genetic proximity of the green algae Zygnematophyceae with land plants.