Abstract:
A greenhouse experiment was conducted to investigat
e the effects of mycorrhial fungus
(
Glomus mosseae
) on cadmium (Cd)
toxicity in pepper (
Capsicum annuum
L. cv.
Zhongjiao 105) plants. Half of plants were inoculat
ed with arbuscular mycorrhizal fungi
(AMF). Cd was supplied in the form of cadmium chlor
ide at 0.0, 0.1 and 0.5 mM through
irrigation water in the soil. Mycorrhizal colonizat
ion was higher in the control than in
cadmium
-
treated soil. Dry weights of root and shoot of myco
rrhizal (M) plants were
higher than non mycorrhizal (NM) ones in both contr
ol and cadmium treatments.
Measurements of Cd concentration indicated that M p
lants immobilized more Cd in the
root and partitioned less Cd to the shoots. Cd decr
eased the leaf chlorophyll content, total
sugar and total protein contents, and the concentra
tions of phosphorous and magnesium.
M plants had greater contents of chlorophyll, total
sugar, total protein and P and Mg
concentrations than NM plants. Moreover, increasing
the Cd concentration caused an
increase in malondialdehyde (MDA) content in leaves
of pepper plants; however, M
plants showed a lower MDA content than NM plants. C
d decreased the activity of
superoxide dismutase (SOD) in leaves of NM and M pl
ants, on the other hand, it
increased the activity of peroxidase (POD) and asco
rbate peroxidase (APX) in leaves of
NM and M plants. APX was stimulated more than POD i
n M plants versus NM plants,
suggesting that APX is a major player in H
2
O
2
-scavenging in M plants. The study suggests
that mycorrhization with G.
mosseae
can be a suitable way to induce Cd-stress resistan
ce
in pepper plants.
Keywords:
Ascorbate peroxidase, Chlorophyll,
Glomus mosseae
, Heavy metals, Root
colonization.
