Symbiotic Fungi: Principles and Practice (Soil Biology)

344 M. Vestberg and A.C. Cassells
Table 21.1 The characterization of PGPR and plant responses to inoculants and activators. The expression of ISR and SAR is characterised by the detection
of the genes PDF1.2 and PR1, respectively. Unless these proteins or their respective mRNAs or other selective marker gene are detected (Hammond-Kosack
and Parker 2003; Reymond and Farmer 1998), the expression of the response should be referred to as increased disease protection
Character Expression Test method Reference
van Wees et al. (1999)
Srinath et al. (2003)
Han et al. (2000); van
Wees et al. (2000)
Zhang et al. (2002)
Spoel et al. (2003)
Pathogen antagonism Inhibition of pathogen growth PGPR spotted at three points on a
culture plate and sprayed with
pathogen spores, inhibition
zones measured
Plant growth promotion Stimulation of plant growth Measurement of plant height/
biomass
Induction of ISR Increased disease protection Root inoculation/challenge of
seedlings
Inoculation of detached leaves with
PGPR followed by spraying of
leaves with pathogen spores
Detection of PDF1.2 (defensin) by
RNA gel blot analysis
Induction of SAR Increased disease protection Foliar inoculation with necrotising
pathogen/challenge inoculation
with second pathogen
Detection of PR1 by RNA gel blot
analysis
Priming of plant defences Increased disease protection Spraying/drenching of plants with
elicitor or plant activator
followed by pathogen challenge
Floating of leaves on plant
activator/challenge inoculation
with pathogen
Van Wees et al. (2000)
Spoel et al. (2003)
Cohen (2002)
Ton et al. (2002)