(go
to KOMUGI Home) (go
to WIS List) (go
to NO.76 Contents)
Wheat Infortnation
Service
Number76: 27-31(1993)
Studies
on enzymatic activities and leakage of solutes from wheat leaf during
an early course of differential brown rust pathogenesis
R.S.Saini1, H.K.L. Chawla2 and
D.S.Wagle2
1Department of Chemistry and Biochemistry, Haryana
Agricultural Univ., Hisar-125 004, India
1Rajasthan Agricultural Univ., Agricultural Research
Station, Durgapura, Jaipur-302 018 India
2Retired
Professor of Biochemistry and formerly, Dean, College of Basic
Sciences and Humanities, Haryana Agricultural University, Hisar-125
004, India
Summary
During progressive brown rust pathogenesis of wheat leaf (cv.
WL711) both susceptible (race 77) and resistant (race 63)
-interactions increased the activity of polyphenoloxidase initially
upto 36 h stage after inoculation. But later on the activity declined
in general towards 72 h stage of infection, however, the decline in
activity was comparatively more in case of the
susceptible-interaction due to race 77. The catalase activity was
also found to be increased at the initial phases of the infection in
both cases but the susceptible-interaction reflected comparatively
higher activity profile. However, during later phases of infection
the activity declined in the susceptible-interaction whereas it
continued to increase in the resistant one. Moreover, the leakage of
amino acids was noted to be comparatively more in the susceptible-
interaction while that of UV-absorbing materials was lesser during
this mutual interacting host- pathogen complexity.
Introduction
The changes in enzymatic activities of peroxidase and phenolase
or phenol oxidases have been multifacially reported in relation to
patho-physiological processes during infection of plants (Farkas and
Kiraly 1958, Seevers et al 1971, Johnson and Cunningham 1972, Bell
1981, Saini et al 1988). Along with enzymatic activities the changes
in membrane permeability are thought to be the initial indicative
results of host pathogen infection process (Hoppe and Heitefuss 1974,
Wheeler 1978, Saini et al 1990). Considering this important aspect of
metabolic activities during plant infection process the present study
was undertaken with an objective to record changes in enzymatic
activities of polyphenoloxidase and catalase along with observing of
leakage pattern of amino acids and UV-absorbing materials from wheat
leaves. This was studied not merely in relation to general infection
process but also in relation to differential (resistant-race 63 and
susceptible-race 77) rust race-interaction during an early course of
brown rust pathogenesis upon Puccinia recondita
inoculation.
Materials and methods
Present study was carried out on wheat (Triticum aestivum,
L.) cv WL711 interacting differentailly when inoculated with two
races of the brown rust pathogen, Puccinia recondita,
viz. race 63-the resistant interaction (rare uredosori formation)
and race 77-the susceptible interaction (heavy uredosori formation).
The winter wheat crop was grown and maintained in the screen house in
earthen pots in the nfixture of sand and farm yard manure in ratio of
3:1 with soil pH 8.3. The pathogen races were multiplied, maintained
and used to inoculate second and third leaf of 25 day old plants.
Plant leaves were sampled for analysis at 0 h (just before
inoculation) 12h, 24h, 36h, 48h and 72h after inoculation as per our
earlier report (Saini et al 1988).
-->Next
(go
to KOMUGI Home) (go
to WIS List) (go
to NO.76 Contents)