In either case, pathogens are recognized and plants activate their defense mechanisms. Pathogen recognition occurs via elicitors or pathogen-associated molecular patterns (PAMPs) that include glycoproteins, peptides, carbohydrates, and lipids [9]. Specific and nonspecific elicitors trigger signal transduction cascades involving protein kinases, elements of the mitogen-activated protein (MAP) kinase pathway, and protein phosphatases [9,10]. Defense mechanisms deployed range from the hypersensitive response (HR), a rapid death of cells at the infection site [8] to systemic acquired resistance (SAR) and induced systemic resistance (ISR) through distinct and coordinated signaling pathways [11-14].

Pathogen-induced systemic resistance is characterized by the accumulation of a suite of pathogenesis-related (PR) proteins and salicylic acid [13,15].

Several genera of fungal, bacterial, and viral pathogens contain species that are specific pathogens to economically important crops.Inducible plant defense is controlled by signal transduction pathways, inducible promoters and cis-regulatory elements corresponding to key genes involved in HR, SAR, ISR, and pathogen-specific responses; any of which could be useful in building phytosensors. Stringent transcriptional regulation of plant responses to pathogens has identified many inducible promoters and cis-acting elements. These cis-acting elements are conserved among plant species, which enables them to be used efficiently as synthetic inducible promoters in heterologous expression systems [16,17].

Employing synthetic promoters with potential inducible elements to engineer plants that can sense the presence of plant pathogens at the molecular level provides insights into the implementation of emerging Brefeldin_A technologies for monitoring and increased resistance to diseases [5].Our present study hinges on inducible regulation of cis-acting elements in transgenic Arabidopsis and tobacco plants, which are model hosts for a wide Drug_discovery range of pathogens to economically important crops.2.?Results and Discussion2.1. Construction of synthetic promoters for pathogen phytosensingBased on our previous study, native pathogen inducible promoters are not sufficient to produce robust reporter signals [18].

Thus, we performed research to design and screen synthetic promoter-reporter gene constructs using inducible regulatory elements based upon published information. Pathogen inducible regulatory elements were grouped according to their responsiveness to plant signal defense molecules: salicylic acid, jasmonic acid and ethylene responsive elements, or classified in accordance to core sequence(s) (e.g., GCC-like boxes, W-like boxes).