Oxidative damage and photosynthetic impairment in tropical rice cultivars upon exposure to excess iron

Authors

  • Samuel de Souza Pinto Federal University of Viçosa
  • Anna Elisa de Souza Federal University of Viçosa
  • Marco Antonio Oliva University of Vila Velha
  • Eduardo Gusmão Pereira Federal University of Viçosa

DOI:

https://doi.org/10.1590/0103-9016-2015-0288

Abstract

Iron plays a pivotal role in the redox reactions of photosynthesis and metabolic processes such as chlorophyll synthesis. Iron availability in waterlogged soils can reach toxic levels and promote oxidative stress. Fe toxicity is the most concerning of stresses for rice in many lowland environments around the world and may cause severe impairments in rice photosynthesis. This study aimed to investigate the extension of oxidative stress after excess Fe exposure and its effects on the photosynthesis of rice cultivars with differential sensitivity. Three Brazilian rice cultivars (EPAGRI 107, BRSMG SELETA and BR IRGA 409) were grown in Hoagland nutrient solution (pH 4.0) with two Fe-EDTA doses corresponding to excess Fe (7 mM) and control (0.009 mM) treatments. After just three days of excess Fe exposure, there was a significant increase in iron concentration in the shoots. The BR IRGA 409 cultivar exhibited higher Fe accumulation in its shoots, and the EPAGRI 107 cultivar recorded the lowest values, which were below the critical toxicity level, as a resistance strategy. Impairment in light energy partitioning and oxidative damage became evident before changes in stomatal resistance, chlorophyll content, maximal PSII quantum yield or visual symptoms for the most sensitive cultivar (BR IRGA 409). The photosynthesis limitations, in addition to the impairment of excess energy dissipation in rice from iron toxicity, are the results of oxidative damage.

Downloads

Download data is not yet available.

Downloads

Published

2016-06-01

Issue

Section

Crop Science

How to Cite

Oxidative damage and photosynthetic impairment in tropical rice cultivars upon exposure to excess iron . (2016). Scientia Agricola, 73(3), 217-226. https://doi.org/10.1590/0103-9016-2015-0288