New Horizons in Insect Science Towards Sustainable Pest Management

66 J. Jani et al.

dent IAA synthesis involved various enzymes of
Pseudomonas, which help in the development of
crop plants. Apart from antibiotic metabolites, it
also secretes organic acid and enzymes, which
are responsible for mineral solubilization and an-
tipathogenic activity.

Insecticidal Activity in Root Associated

Pseudomonads

It is reported indisputably that some of the root-
associated Pseudomonas strains express chitin-
ase and/or chitinase like metabolite and show
potent insecticidal activity during in vitro stud-
ies (Mette and Jan 1999 ; Nandakumar et al.
2007 ; Ramarathnam et al. 2011 ). Moreover anti-
insect activity is due, in part, to the production
of a novel protein toxin (Ramarathnam et al.
2011 ) that is related to insect toxins produced
by entomopathogenic bacteria associated with
insect-invading nematodes. However, P. stutzeri

and P. fluorescens have been found to produce

chitinolytic activity in batch growth cultures, but

the enzyme activity has not been characterized in

detail. P. aeruginosa has been reported fleetingly

for the chitinase activity. It posses two isozymes

(FI and FII) for endochitinase activity against in-

sect (Wang and chang 1997 ; Mette and Jan 1999 )

(Table 2 ).

Interactions in Rhizosphere

Pseudomonas spp. is adapted to survival in soil

and colonization of plant roots (Kiely et al. 2006 ;

Arima et al. 1964 ). Biological control of threats

by pseudomonas depends on biochemical com-

pound that attack the parasites. Such mechanism

principally affected by effective colonization

capability of the bioagent in rhizosphere and

phyllosphere. Effective colonization on the plant

system as well as inside root tissues system is a

specific trait and may noticeably aid biocontrol

Table 2 List of metabolites of Pseudomonas acquiesced for plant health
Metabolites Characteristics Name Promising strains
Class I
Antifungal antibiotic Non volatile Phenazine
Pyrrolnitrin
Pyoluteorin
2,4 Diacetylphloroglucinol
(DPAG, Phl)

Pf CHAO

Pseudomonas chlororaphis

Pseudomonas aureofaciens

Pf-5

Cyclic peptides Lokisin Pf dr54

Volatile HCN Pf CHAO

Antinematode 2,4 diacetylphloroglucinol

(DPAG, Phl)

HCN

Pf CHAO

Antibacterial

antibiotic

Secondary metabolites Pseudomonic acid

Oomycin

Pyrrolnitrin

Pseudomonas putida

Antiviral antibiotic Secondary metabolite Karalicin Pseudomonas rotkzi

Class II

Siderophores Coloured pigment

Ion chelating

Pseudobactin

Pyochelin (Cu++ and Zn++)

Pyoverdin

Pseudomonas aeruginosa

Pseudomonas fluorescence

Phyto-hormones Auxins IAA Pf-5

Antifungal enzymes Chitinases

β-1,3-glucanases

β-1,4-glucanases

Lipase (EC.3.1.1.3)

Pf-5

Acids Phosphate solubilization Gluconic acids Pseudomonas cepacia