Metabolites of Pseudomonads: A New Avenue of Plant Health Management 63
els to explain the post-transcriptional control
of metabolite in Pseudomonas spp. and it has
been proved in P. fluorescens CHAO (Bjorn-
lund et al. 2009 ; Reddy 2009 ). GacS/GacA path-
way plays an important role in contributing the
antipathogenicity against Pythium ultimum and
it also induces stress in nematode (Haas and
Defago 2005 ). It confirmed that Pseudomonas
spp. control over nematode infection (Siddiqui
et al. 2006 ) and GacS\GacA pathway, DAPG is
the most important factor in stress enhancement
in Caenorhabditis elegans (Neidig et al. 2011 ).
Role of Secondary Metabolites
in Bacterial supremacy
Pseudomonads are ubiquitous soil microflora
playing an important role in plant protection.
The suspicion benefits of these depends on vari-
ous factors, such as their ability to efficiently
exploit root exudates and to withstand preda-
tion by nematodes and protozoa (de Mesel et al.
2004 ; Jousset et al. 2008 ; Pedersen et al. 2009 ;
Rosenberg et al. 2009 ). Bacteria have evolved
an array of anti-predatory resistance mecha-
nisms, such as toxicity, and in soil, unpalatable
or toxic strains again competitive advantage in
presence of predators (Ronn et al. 2001 ; Jousset
et al. 2008 ). Extracellular metabolites of Pseu-
domonas spp. drive complex interactions with
predators, affecting their physiology and behav-
iour. Secondary metabolite works specifically on
predators, acting as repellents, stressors or tox-
ics. Production of secondary metabolites by bio-
control bacteria serves multiple functions, and
metabolites protecting plants against pathogens
improve bacterial resistance against predator
(Bjornlund et al. 2009 ; Pedersen et al. 2009 ; Nei-
dig et al. 2011 ).