Role of the cyclic lipopeptide massetolide A in biological control of Phytophthora infestans and in colonization of tomato plants by Pseudomonas fluorescens

Abstract

Summary• Pseudomonas strains have shown promising results in biological control of late blight caused by Phytophthora infestans . However, the mechanism(s) and metabolites involved are in many cases poorly understood. Here, the role of the cyclic lipopeptide massetolide A of Pseudomonas fluorescens SS101 in biocontrol of tomato late blight was examined.• Pseudomonas fluorescens SS101 was effective in preventing infection of tomato ( Lycopersicon esculentum ) leaves by P. infestans and significantly reduced the expansion of existing late blight lesions. Massetolide A was an important component of the activity of P. fluorescens SS101, since the massA -mutant was significantly less effective in biocontrol, and purified massetolide A provided significant control of P. infestans , both locally and systemically via induced resistance.• Assays with nahG transgenic plants indicated that the systemic resistance response induced by SS101 or massetolide A was independent of salicylic acid signalling. Strain SS101 colonized the roots of tomato seedlings significantly better than its massAmutant, indicating that massetolide A was an important trait in plant colonization.• This study shows that the cyclic lipopeptide surfactant massetolide A is a metabolite with versatile functions in the ecology of P. fluorescens SS101 and in interactions with tomato plants and the late blight pathogen P. infestans .

Cyclic Lipopeptide Surfactant Production by Pseudomonas fluorescens SS101 Is Not Required for Suppression of Complex Pythium spp. Populations

“…Certain antimicrobial compounds produced by rhizobacteria possess the capacity to limit plant disease development, both directly by limiting growth of the pathogen and indirectly via the induction of plant defense responses (13,31,37). Recent studies by Tran et al (36) indicated that massetolide A induces resistance in tomato plants against Phytophthora infestans. Work by Ongena et al (27) suggested that fengycins, CLPs produced by B. subtilis, could be involved in eliciting induced resistance, whereas the structurally different CLP mycosubtilin most likely does not have resistance-inducing activities (17).…”

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.…”

The rhizosphere: a playground and battlefield for soilborne pathogens and beneficial microorganisms

“…ISR can also take place following exposure of the plant to compounds produced by plant-beneficial bacteria, e.g. the volatile 2,3-butanediol (Ryu et al 2004), the siderophore pyoverdine (Maurhofer et al 1994), DAPG (Iavicoli et al 2003), and cyclic lipopeptide surfactants (Ongena et al 2007;Tran et al 2007). …”