Systemic Acquired Resistance.

Elucidating Pathways Controlling Induced Resistance

“…A localized predisposing infection with a necrotizing pathogen usually results in a type of resistance referred to as systemic acquired resistance (SAR). SAR has been described for a large number of plant species [5,6,42]. A phenotypically similar type of resistance is observed following the colonization of plant roots by selected strains of non-pathogenic Pseudomonas fluorescens bacteria.…”

“…The best investigated chemical inducers are salicylic acid (SA) and its functional analogues 2,6-dichloroisonicotinic acid (INA) and benzothiadiazole (BTH) [43]. INA and BTH are thought to induce a resistance type similar to SAR because they activate the same set of defense-related genes and are effective against the same spectrum of plant pathogens [5]. The non-protein amino acid ß-aminobutyric acid (BABA), a powerful chemical inducer of broad-spectrum resistance in different plant species [8,44], on the contrary seems to be able to operate independently from an initial SAR gene induction [45,46].…”

“…In contrast to the above-mentioned constitutive types of resistance, plants also possess adaptive defense mechanisms to defend themselves against pathogen or insect attack. Following an appropriate stimulation, they are capable of developing an enhanced defensive capacity, commonly referred to as induced resistance [5,6,7,8]. …”

How does SA signaling link the Flg22 responses?

“…In Arabidopsis, basal levels of cellular SA are approximately 15 mM. Following pathogen infection, SA is synthesized through the isochorismate pathway [11][12][13] and can increase to approximately 200 mM. Flg22 treatments also enhance SA biosynthesis.…”

Plant Growth Promoting Rhizobacteria (PGPR): A Bioprotectant bioinoculant for Sustainable Agrobiology. A Review

“…The gene and gene product involve in this form of biological control phenomenon has not been well documented. Unlike the systemic acquired resistance (SAR) (Handelsman and Stabb 1996), which is a stateof defense that is activated all through the plant following the primary infection by pathogens (Ryals et al 1996), Induce systemic resistance (ISR) utilize organic acid and plant hormones (salicylic acid, jasmonic acid, and ethylene) in plants signaling and stimulation of the host plant defense response against variety of plant pathogens (Niranjan et al 2005;Beneduzi et al 2012;Pieterse et al 2014). PGPR response to ISR is usually felt by increased physical and mechanical strength of the cell wall as well as adjusting their physical and biochemical reaction to environmental stress (Labuschagne et al 2010).ISR in PGPR can be in the form of salicylic acid, siderophores production, lipopolysaccharide, flagella, N-acyl homoserine lactone (AHL) molecules (Van Loon 2007;Shuhegger et al 2006) and antibiotics.…”