Journal des techniques analytiques et bioanalytiques

Abstrait

2D-PAGE of Cashew Stem Coupled to LC ESI Q-TOF MS/MS Reveals Abundance of Antioxidant Enzymes and Heat Shock Proteins, Compatible with the Crop Adaptation to the Semi-Arid Conditions of Tropical Countries

Darcy MF Gondim, Ilka M Vasconcelos, Frederico BMB Moreno, Ana CO Monteiro-Moreira, Jose H Araújo-Filho, Jeferson Segalin, Paulo M Pinto, Célia RRS Carlini, Jose E Cardoso and Jose TA Oliveira

Cashew crop grown in the semi-arid conditions of tropical countries produces cashew nut, an important commodity both for internal consumption and exportation. Cashew is very well adapted to abiotic stresses such as drought, high temperature, high salinity, and solar radiation predominant in the environmental regions where cashew is cultivated. Besides cashew is threatened by a great variety of fungal diseases amongst them gummosis caused by the devastating fungus Lasiodiploidea theobromae that has increased its severity in all northeastern Brazil producing states. Therefore there is a great interest in understanding the biochemical/physiological traits associated with both the climate adaptation of cashew and the resistance/susceptibility to L. theobromae.
This paper reports on the evaluation of a proteomic approach to study the proteins of the cashew stems, a recalcitrant plant tissue, where the L. theobromae infection establishes. After testing different methods for extracting proteins from cashew stems, the precipitation with trichloroacetic acid/acetone combined with the use of an optimized phenol extraction method produced a cashew protein sample free of interfering compounds that showed a highquality 2D-PAGE pattern. The extraction method devised allowed the fractionation of approximately 615 spots from which 130 proteins were identified. Of them 31% are related to plant disease/defense, which is consistent with the excellent fit of cashew to the semi-arid conditions. Therefore, this pioneering map derived from CCP (Premature Cashew Clone) 76, a semiarid-tolerant cashew clone, provides the basis for further investigations of cashew physiology such as detection of genetic reprogramming induced by biotic and abiotic stresses.