BIOCONTROL STRAIN OF BACILLUS-SUBTILIS AF-1 RAPIDLY INDUCES LIPOXYGENASE IN GROUNDNUT (ARACHIS-HYPOGAEA L.) COMPARED TO CROWN ROT PATHOGEN ASPERGILLUS-NIGER
Pr. Sailaja et al., BIOCONTROL STRAIN OF BACILLUS-SUBTILIS AF-1 RAPIDLY INDUCES LIPOXYGENASE IN GROUNDNUT (ARACHIS-HYPOGAEA L.) COMPARED TO CROWN ROT PATHOGEN ASPERGILLUS-NIGER, European journal of plant pathology, 104(2), 1998, pp. 125-132
Metabolic products of polyunsaturated fatty acids have been variously
implicated in control of microbial pathogens. Induced resistance has b
een shown as one of the mechanisms of biological control by plant grow
th promoting rhizobacteria (PGPR). This paper reports a significant li
poxygenase (LOX) activity in groundnut seedlings with production of 13
-hydroperoxyoctadecadienoic acid (13-HPODE) and 13-hydroperoxyoctadeca
trienoic acid (13-HPOTrE) as major products with linoleic acid (LA) an
d alpha-linolenic acid (ALA), respectively. Both the hydroperoxides ar
e inhibitory to the growth of Aspergillus niger as measured in micro t
iter plates. Ours is the first report on induction of LOX activities i
n groundnut on treatment with a PGPR strain Bacillus subtilis AF 1, an
d with crown-rot pathogen, A. niger. Treatment with B. subtilis AF 1 e
nhanced LOX levels in groundnut similarly but earlier to A. niger-trea
tment. This induction of LOX during activation of growth and pathogen
infection was discussed in light of the reported involvement of LOX bo
th in growth and development as well as in plant-pathogen interaction,
particularly induced disease resistance.