Lipoxygenase metabolites of alpha-linolenic acid in the development of resistance in pigeonpea, Cajanus cajan (L.) Millsp, seedlings against Fusariumudum infection
Pum. Devi et al., Lipoxygenase metabolites of alpha-linolenic acid in the development of resistance in pigeonpea, Cajanus cajan (L.) Millsp, seedlings against Fusariumudum infection, EUR J PL P, 106(9), 2000, pp. 857-865
Lipoxygenase (LOX) activity was measured in germinating pigeonpea Cajanus c
ajan seedlings, resistant (ICP-8863) and susceptible (ICP-2376) to wilt fun
gus, before and after infection with Fusarium udum. LOX activity was signif
icantly higher in the resistant than in the susceptible cultivars of pigeon
pea and was enhanced further in response to infection with Fusarium udum. T
his increase in LOX activity in the resistant cultivars of pigeonpea appear
s to be due to the induction of lipoxygenase isozymes in response to infect
ion. Analysis of the endogenous LOX metabolites in pigeonpea seedlings reve
aled the predominant formation of 13-hydroperoxyoctadecadienoic acid (13-HP
ODE) in healthy seedlings and 13-hydroperoxyoctadecatrienoic acid (13-HPOTr
E) in infected seedlings. Further studies on the effects of LOX metabolites
on the growth and multiplication of Fusarium udum showed that HPOTrEs, LOX
metabolites of alpha -linolenic acid, are more anti-fungal compared to HPO
DEs, LOX metabolites of linoleic acid.