In order to investigate the effects of IAA on physiological response and cadmium tolerance of Trichosanthes kirilowii Maxim. under cadmium stress
Baoding T. kirilowii (cadmium-tolerant) and Pujiang T. kirilowii were selected as experimental materials
and soil culture experiments were conducted to determine the effects of exogenous IAA (10
35 and 60 μmol/L) on physiological changes
photosynthetic characteristics
antioxidant enzyme activity and malondialdehyde (MDA) content of these two varieties under 800 μmol/L cadmium stress. The results showed that:(1) Compared with the CK
the average root length
fresh weight of underground part
superoxide dismutase (SOD) activity
chlorophyll content
maximum photochemical efficiency (Fv/Fm) and electron transfer rate (ETR) of the two kinds of T. kirilowii significantly decreased under 800 μmol/L Cd treatment
while the initial fluorescence (Fo)
peroxidase (POD) activity
catalase (CAT) activity and MDA content increased significantly
and the lipid peroxidation of cell membrane deepened. (2) With the increasing of IAA concentration
the average root length and fresh weight of underground part of Baoding T. kirilowii increased continuously
with the maximum increase of 24.83% and 40.55%
while those of Pujiang T. kirilowii changed from ascending to descending. (3) After the addition of IAA
the content of chlorophyll a
b
a+b and chlorophyll a/b
Fv/Fm
ETR
SOD
POD and CAT activities in the young leaves of the two varieties increased first and then decreased
while Fo and MDA content dropped firstly and then increased. The content of chlorophyll a
b
a+b
a/b
Fv/Fm
ETR
SOD and CAT increased to the peak values with the addition of IAA at 35 μmol/L
while MDA decreased by 35.44%~43.23%
reaching the valley value. (4) The analysis of membership function indicated that the ability of cadmium tolerance of different IAA concentrations was 35 μmol/L > 10 μmol/L > 60 μmol/L > 0 μmol/L. Therefore
applying exogenous IAA has a certain application prospect in alleviating cadmium stress in plants.
Singh S, Prasad S M. IAA alleviates Cd toxicity on growth, photosynthesis and oxidative damages in eggplant seedlings[J].Plant Growth Regulation,2015,77(1):87-98.
Bashri G, Prasad S M. Exogenous IAA differentially affects growth, oxidative stress and antioxidants system in Cd stressed
Trigonella foenum-graecum
L. seedlings:Toxicity alleviation by up-regulation of ascorbate- glutathione cycle[J]. Ecotoxicology and Environmental Safety,2016,132:329-338.