Pseudomonas fluorescens WCS374r-Induced Systemic Resistance in Rice against Magnaporthe oryzae Is Based on Pseudobactin-Mediated Priming for a Salicylic Acid-Repressible Multifaceted Defense Response

Effects of Colonization of a Bacterial Endophyte,Azospirillumsp. B510, on Disease Resistance in Rice

“…ISRs induced by P. fluorescens WCS374r, P. aeruginosa 7NSK2, and Serratia plymuthica IC1270 have been reported to exhibit 35 to 47% protection against rice blast disease. 7,12,23) As shown in Fig. 2, endophytic colonization of rice by Azospirillum sp.…”

Rice RING protein OsBBI1 with E3 ligase activity confers broad-spectrum resistance against Magnaporthe oryzae by modifying the cell wall defence

“…The invasion of M. oryzae hyphae often stimulates rapid production of H 2 O 2 in rice cells at infection sites as an early defence response [59]. Small GTPase Rac complex-mediated accumulation of ROS generated through NADPH oxidases is required for innate immune response against M. oryzae [11][12][13][14][15].…”

“…To detect phenolic compounds, sheath segments were stained for 30 min in a solution containing 0.01% (w/v) aniline blue and 0.15 M K 2 HPO 4 . They were visualized as autofluorescence under blue light epifluorescence with a Leica TCS SP5 fluorescent microscopy (GPF filter set; excitation at 405 nm, dichroic beamsplitter of 500-550 nm; Leica Microsystems, Hong Kong, China) according to the method described previously [59]. To detect protein cross-linking, sheath segments were submerged in 1% sodium dodecyl sulphate (SDS) for 24 h at 80 °C and stained in 0.1% Coomassie Brilliant Blue in a solution of 40% ethanol and 10% acetic acid for 15 min.…”

Jasmonate signaling in plant interactions with resistance-inducing beneficial microbes

“…Moreover, transgenic Arabidopsis NahG plants that are unable to accumulate SA due to ectopic expression of the bacterial salicylate hydroxylase gene nahG, showed a similar level of induced disease resistance upon colonization of the roots by WCS417r as did wildtype plants, indicating that WCS417r-ISR functions independently of SA (Pieterse et al, 1996). Since then, many examples of SA-independent ISR have been demonstrated in Arabidopsis (Ahn et al, 2007;Iavicoli et al, 2003;Ryu et al, 2003;Segarra et al, 2009;Stein et al, 2008;Van Wees et al, 1997) and other plant species, such as tobacco (Press et al, 1997;Zhang et al, 2002), cucumber (Press et al, 1997), tomato (Hase et al, 2008;Tran et al, 2007;Yan et al, 2002), and rice (De Vleesschauwer et al, 2008). Hence, the ability to activate an SA-independent pathway controlling systemic disease resistance seems to be common for beneficial microorganisms and occurs in a broad range of plant species against different types of attackers.…”

“…Similarly, colonization of the roots of wildtype and nahG-expressing tomato plants by the non-pathogenic oomycete P. oligandrum resulted in a decrease in Ralstonia solanacearum-inflicted disease symptoms, whereas the ISR response was blocked in mutant jai1 (jasmonic acid insensitive 1) plants (Hase et al, 2008). In addition, using nahG-expressing rice, an ET-insensitive OsEIN2 antisense rice line, and the JA-deficient rice mutant hebiba, De Vleesschauwer et al (2008) demonstrated that the ability of P. fluorescens WCS374r to trigger ISR against the rice leaf blast pathogen Magnaporthe oryzae is regulated by an SA-independent but JA/ET-modulated signaling pathway. In cucumber, application of the chemical inhibitors silver thiosulfate and diethyldithiocarbamate, which block the action of ET and the synthesis of JA, respectively, reduced Trichoderma asperellum T203-mediated ISR against P. syringae pv.…”