ABSTRACT. Fusarium wilt caused by Fusarium oxysporum f. sp lycopersici (Fol) is one of the main diseases affecting tomatoes. The BHRS 2,3 genotype of tomato is, however, resistant to this disease. A proteomic approach was used to understand the defense mechanisms of this genotype using the tomato root, the first tissue that interacts with the fungus, as a target. Protein was extracted and separated by two-dimensional electrophoresis followed by staining with Coomassie brilliant blue. The proteins were identified by MALDI-TOF/TOF mass spectrometry. A total of 22 proteins were identified, 21 of which showed differential expression with 12 proteins being upregulated and nine being downregulated. Plants responded to the pathogen with increased expression of pathogenesis-related proteins. We noted the induction of proteins involved in hypersensitivity reaction and other defense mechanisms. The expression of proteins of primary metabolism related to energy production, however, decreased, as did the expression of two proteins related to defense against abiotic stress. These results demonstrate the presence of important mechanisms for defense against Fol in the tomato genotype BHRS 2,3.

This research aims to analyze the effect of the extract from a native plant from Caatinga, Allamanda blanchetti, in the induction of resistance mechanisms in a sugarcane variety smut-susceptible. Initially, it carried out a phytochemical analysis to know the main plant compounds used in this study. Diverse chemicals content in ethanolic extract from A. blanchetii were detected by thin-layer chromatography (TLC). Flavonoids, were more abundant compounds following by terpenes, stereroids and saponins. Under greenhouse conditions the sugarcane plants, SP-791011 (smut-susceptible), were sprayed with extracts from A. blanchetti extracted at cold at concentrations of 1000 ppm and acilbenzolar-S-metil (ASM) (100 mg/L). Leaves were collected at 0, 24 and 48 hours after spraying and used in the RT-PCR analysis for to identify the defense gene expression. Change in gene expression were observed in the different treatments, especially in the expression of pathogenesis-related (PR) genes. The extract of A. blanchetti induced an increase in the glucanase expression and was more effective than ASM inducer. SNPR1 gene show increased in the two treatment. The results indicate that A. blanchetti extracts was able to activate the resistance mechanism as observed in resistant plants. This paper is the first report about the use of Caatinga natural plant extracts inducing resistance genes against Sporisorium scitamineum in sugarcane susceptible genotype.