Acta Physiologiae Plantarum

, Volume 32, Issue 5, pp 925–932

Modulation of symbiotic efficiency and nodular antioxidant enzyme activities in two Phaseolus vulgaris genotypes under salinity

Authors

  • Salwa Jebara
    • Centre of Biotechnology Borj Cedria (CBBC)
  • Jean Jacque Drevon
    • UMR1222 Rhizosphère & Symbiose INRA-AGRO.M
    • Centre of Biotechnology Borj Cedria (CBBC)
Original Paper

DOI: 10.1007/s11738-010-0480-3

Cite this article as:
Jebara, S., Drevon, J.J. & Jebara, M. Acta Physiol Plant (2010) 32: 925. doi:10.1007/s11738-010-0480-3

Abstract

To analyse nodular expression of antioxidant enzymes depending on plant genotype and salinity, two Phaseolus vulgaris genotypes, tolerant BAT477 and sensitive COCOT, were inoculated with the reference strain Rhizobium tropici CIAT899 and grown under 25 and 50 mM NaCl. Plant growth, nodulation and nitrogen fixing activity measured by the acetylene reducing activity (ARA) as an indicator of nitrogenase (E.C. 1.7.9.92) activity were more affected by salt concentrations in COCOT than in BAT477, particularly with 50 mM NaCl. Electrophoresis analysis of antioxidant enzymes in nodules, roots and free-living rhizobia showed that only catalase (CAT E.C. 1.11.1.6) isoenzymes varied with genotype. The sensitive genotype showed lower antioxidant enzyme activities than tolerant genotype and it was more affected by salinity. In the tolerant genotype catalase and ascorbate peroxidase (APX, E.C. 1.11.1.11) were inhibited by salt stress, whereas superoxide dismutase (SOD, E.C. 1.15.1.1) and peroxidase (POX, E.C. 1.11.1.7) were activated by salinity. Statistical analysis allowed suggesting that tolerance to salinity is associated with a differential regulation of distinct superoxide dismutase and peroxidase activities.

Keywords

Antioxidant enzymes Ascorbate peroxidase Catalase Nitrogen fixing activity Nodule Peroxidase Rhizobium Salinity Superoxide dismutase

Abbreviations

APX

Ascorbate peroxidase

ARA

Acetylene reducing activity

ASC-GSH cycle

Ascorbate–glutathione cycle

CAT

Catalase

EDTA

Ethylenediaminetetraacetic acid

MTT

3-(4,5-Dimethlthiazol-2-4)-5-5diphenyl tetrazolium bromide

NBT

Nitroblue tetrazolium

NDW

Nodule dry weight

PMSF

Phenylmethylsulfonyl fluoride

POX

Guaiacol peroxidase

PVP

Polyvinyl-pyrrolidone

ROS

Reactive oxygen species

RDW

Root dry weight

SDW

Shoot dry weight

SOD

Superoxide dismutase

TEMED

N,N,N′,N′-tetramethyl ethylene diamine

Tris

Tris (hydroxymethyl) aminomethane

Copyright information

© Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków 2010