From seed to whole plant: Seed defense priming by rhizobacteria and their metabolites
C. RYU (1), G. Song (1), H. Choi (1), Y. Kim (2) (1) KRIBB, South Korea; (2) KRICT, South Korea

Seed priming is a technique to be controlled hydration and drying of seeds resulting in more rapid germination when are re-imbibed. Defense priming that has been induced by pre-treatment of certain beneficial microbes and natural/synthetic compounds can enhance defense responses more rapidly or aggressively to biotic- or abiotic stresses. In this study, we were newly developed a immerged technology of the two priming methods referred to as “seed defense priming (SDP)” that is by seed priming with its heat stable supernatant (secreted metabolites) from root-associated Bacillus spp. in order to induction of systemic resistance (ISR) after transplanting to field. SDP mediated by bacterial supernatants from the 1816 strains of Bacillus spp. isolated from various soil samples in South Korea were tested ISR against Pseudomonas syringae pv. lachrymans in cucumber seedlings. Symptom development on the SDP with selected strain PB69 was reduced 40 % in vitro. Under field condition, SDP by Bacillus spp. strain PB69 significantly reduced disease severity against Xanthomonas axonopodis pv. vesicatoria (Xav) as compared to control treatment at 20 and 30 DAT. The results of quantitative real-time PCR show that SDP with selected strain PB69 and subsequent pathogen challenge upregulated CaLOX expression in the field-grown pepper plants. Our results indicate that SDP triggered by bacterial supernatant can be de novo method to induced ISR. SDP with PB69 triggers induced resistance in crops by priming JA signaling pathways under field condition.

Abstract Number: P5-127
Session Type: Poster