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Defence‐Related Enzymes in Soybean Resistance to Target Spot
Author(s) -
Fortunato Alessandro A.,
Debona Daniel,
Bernardeli Arthur M. A.,
Rodrigues Fabrício A.
Publication year - 2015
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/jph.12370
Subject(s) - corynespora cassiicola , biology , cultivar , inoculation , leaf spot , horticulture , peroxidase , fungus , enzyme , phenylalanine ammonia lyase , enzyme assay , plant disease resistance , botany , biochemistry , gene
Target spot, caused by the fungus Corynespora cassiicola , has become a serious foliar disease in soybean production in the Brazilian Cerrado. Information in the literature regarding the biochemical defence responses of soybean to C. cassiicola infection is rare. Therefore, the objective of this study was to determine the biochemical features associated with soybean resistance to target spot. The activities of chitinases ( CHI ), β ‐1‐3‐glucanases ( GLU ), phenylalanine ammonia‐lyases ( PAL ), peroxidases ( POX ), polyphenol oxidases ( PPO ) and lipoxygenases ( LOX ), as well as the concentrations of total soluble phenolics ( TSP ) and lignin‐thioglycolic acid ( LTGA ) derivatives, were determined in soybean leaves from both a resistant ( FUNDACEP 59) and a susceptible ( TMG 132) cultivar. The target spot severity, number of lesions per cm 2 of leaflet and area under the disease progress curve were significantly lower for plants from cv. FUNDACEP 59 compared to plants from cv. TMG 132. The GLU , CHI , PAL , POX and PPO activities and the concentration of LTGA derivatives increased significantly, whereas LOX activity decreased significantly on the leaves infected by C. cassiicola . Inoculated plants from cv. FUNDACEP 59 showed a higher PPO activity and concentrations of TSP and LTGA derivatives at 4 and 6 days after inoculation compared to plants from cv. TMG 132. In conclusion, the results of this study demonstrated that the defence‐related enzyme activities increased upon C. cassiicola infection, regardless of the basal level of resistance of the cultivar studied. The increases in PPO activity and concentrations of TSP and LTGA derivatives, but lower LOX activity, at early stages of C. cassiicola infection were highly associated with soybean resistance to target spot.