S. Peltonen, Responses of barley and wheat to pathogens, non-pathogens and wounding as indicated by induced phenylalanine ammonia-lyase activity, ACT AG SC B, 48(3), 1998, pp. 184-191
Citations number
34
Categorie Soggetti
Agriculture/Agronomy
Journal title
ACTA AGRICULTURAE SCANDINAVICA SECTION B-SOIL AND PLANT SCIENCE
Phenylalanine ammonia-lyase (PAL) activity was strongly induced in barley a
nd wheat leaves after inoculation with highly or weakly aggressive isolates
of Bipolaris sorokiniana. Aggressive isolates, however: generated much str
onger early induction of PAL than less aggressive isolates. The non-pathoge
ns Drechslera teres (in wheat), Stagonospora nordorum (in barley), Botrytis
cinerea, Trichoderma reesei and the root and stem pathogen Fusarium culmor
um caused no clear induction of PAL on intact barley or wheat leaves. They
were able to induce PAL at the wound margins of barley leaves, although at
a lower level than B. sorokiniana. Wounding alone did not induce PAL. Prior
inoculation of barley leaves with non-pathogens provided partial protectio
n against a subsequent challenge with B. sorokiniana seven days later. Indu
ced plants showed unchanged PAL activity levels compared to non-induced pla
nts after challenge inoculation. The results suggest that PAL plays a role
in the active defences of barley and wheat in response to pathogen attack,
but apparently not in response to non-pathogens, wounding, or in plants exp
ressing induced resistance.