Photoacclimation in a tropical population of Cladophora glomerata (L. ) Kützing 1843 (Chlorophyta) from southeastern Brazil

Author(s)

Bautista, A. I. N. ; Necchi Júnior, Orlando ^[2]

• Document type: Journal article
• Source: Brazilian Journal of Biology; v. 68, n. 1, p. 129-136, Feb. 2008.
• Field of knowledge: Biological Sciences - Botany

Abstract

Photoacclimation of photosynthesis was investigated in a tropical population of C. glomerata (São Paulo State, southeastern Brazil, 20º 48 24" S and 49º 22 24" W) by chlorophyll fluorescence parameters and chlorophyll a content. Plants were acclimated to two levels of irradiance: low (65 ± 5 µmol.m-2.s-1) and high (300 ± 10 µmol.m-2.s-1) and exposed short-term (4 days) and long-term (28 days) under a light-dark cycle of 12:12 hours. Photosynthesis-irradiance (PI) curves revealed distinct strategies of photoacclimation. In long-term exposure, plants acclimated by altering the photosynthetic units (PSU) number and keeping fixed the PSU size, revealed by increased rates of maximum photosynthesis (Pmax), lower photosynthetic efficiency (alpha) and higher values of the saturation parameter (Ik) under high irradiance... (AU)

• FAPESP's process: 01/06139-3 - Comparative ecophysiological analysis between species of macroalgae from lotic environments: temperature and irradiance
• Grantee: Orlando Necchi Junior
• Support Opportunities: Regular Research Grants