PAntibioticPred is to predict the enzymes involved in antibiotic biosynthetic pathways in plant growth promoting Pseudomonas species.
Biosynthesis of antibiotics by plant growth promoting rhizobacteria
Plant growth promoting rhizobacteria (PGPR) play a vital role in crop protection,
growth promotion and in the improvement of soil health. Some well known PGPR strains are
Pseudomonas, Bacillus, Azospirillum, Rhizobium, and Serratia species. The primary mechanism
of biocontrol by PGPR involves the production of antibiotics such as phenazine-1-carboxyclic
acid, 2, 4-diacetyl phloroglucinol, oomycin, pyoluteorin, pyrrolnitrin, kanosamine, zwittermycin-A,
and pantocin. A cascade of endogenous signals such as sensor kinases, N-acyl homoserine
lactones and sigma factors regulates the synthesis of antibiotics. The genes responsible
for the synthesis of antibiotics are highly conserved. The antibiotics pertain to
polyketides, heterocyclic nitrogenous compounds and lipopeptides have broad-spectrum action
against several plant pathogens, affecting crop plants. In addition to direct anti-pathogenic
action, they also serve as determinants in triggering induced systemic resistance (ISR) in the plant system.
Phenazine is a low molecular weight secondary metabolite, nitrogen
containing heterocyclic antimicrobial compound consisting of brightly
coloured pigment produced by the bacterial genera pertaining to
Pseudomonas, Burkholderia, Brevibacterium and Streptomyces.
Pyrrolnitrin (PRN) is a chlorinated phenylpyrrole antibiotic
produced by several fluorescent and non-fluorescent pseudomonads. It was
first isolated from Burkholderia pyrrocinia.
Pyoluteorin (Plt) is a phenolic polyketide with resorcinol ring. The
ring is linked to a bichlorinated pyrrole moiety. Biosynthesis of pyrrole
moiety is unknown. It was first isolated from P. aeruginosa followed by P.
fluoresens Pf-5 and CHAO. Plt has bactericidal, herbicidal and fungicidal properties. Application of Plt to
cotton seeds suppressed cotton damping-off.
Phloroglucinol antibiotics are phenolic bacterial and plant metabolites with antifungal,
antibacterial, phototoxic, antiviral, and anthelmintic activity. Of particular interest is
2,4-diacetylphloroglucinol (DAPG), because of its production by fluorescent Pseudomonas spp.
of worldwide origin. This polyketide antibiotic DAPG is a phenolic molecule synthesized
by the condensation of three molecules of acetyl coenzymeA with one molecule of malonyl coenzymeA
to produce the precursor monoacetylphloroglucinol, which is subsequently transacetylated to generate
PHL utilizing a CHS-type enzyme. Biosynthetic locus of DAPG is highly conserved. It comprises the
biosynthetic genes phlACBD.