Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae

Authors

  • Wiler Ribas Moreira Federal Rural University of Pernambuco; Dept. of Agronomy; Universidade Federal Rural de Pernambuco
  • Wilka Messner da Silva Bispo Federal University of Viçosa; Dept. of Plant Pathology; Universidade Federal de Viçosa
  • Jonas Alberto Rios Federal University of Viçosa; Dept. of Plant Pathology; Universidade Federal de Viçosa
  • Daniel Debona Federal University of Viçosa; Dept. of Plant Pathology; Universidade Federal de Viçosa
  • Clístenes Williams Araújo Nascimento Federal Rural University of Pernambuco; Dept. of Agronomy; Universidade Federal Rural de Pernambuco
  • Fabrício Ávila Rodrigues Federal University of Viçosa; Dept. of Plant Pathology; Universidade Federal de Viçosa

DOI:

https://doi.org/10.1590/0103-9016-2014-0312

Abstract

Brown spot (BS), caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg) on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L.) plants (cv. Metica-1) grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids), were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites.

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Published

2015-08-01

How to Cite

Moreira, W. R., Bispo, W. M. da S., Rios, J. A., Debona, D., Nascimento, C. W. A., & Rodrigues, F. Ávila. (2015). Magnesium-induced alterations in the photosynthetic performance and resistance of rice plants infected with Bipolaris oryzae . Scientia Agricola, 72(4), 328-333. https://doi.org/10.1590/0103-9016-2014-0312

Issue

Section

Plant Pathology