Physiological basis of different allelopathic reactions of cucumber and figleaf gourd plants to cinnamic acid.
To provide an insight into the mechanism of interspecific interactions mediated by allelochemicals, cucumber and figleaf gourd seedlings were compared on their response to cinnamic acid, an autotoxin from root exudates of cucumber. Reactive oxygen species metabolism and plasma membrane H(+)-ATPase activity were examined in roots upon exposure to cinnamic acid. This exposure resulted in significant increases in activities of NADPH oxidase, superoxide dismutase, guaiacol peroxidase, and catalase, as well as in O(2)(.-) production and H(2)O(2) content, in cucumber roots but not in figleaf gourd roots. Notably, the cucumber roots produced significant amount of reactive oxygen species (ROS) immediately after cinnamic acid treatment, consequently increasing membrane peroxidation, decreasing membrane H(+)-ATPase activity, and losing root viability. By contrast, no such changes were observed in figleaf gourd roots. All these results indicated that there was an interspecies difference in the recognition of allelochemicals, which induced oxidative stress accompanied by root cell death in cucumber, an autotoxic plant, but not in figleaf gourd, a cucumber relative.
Ding
Ju
J
Department of Horticulture, Huajiachi Campus, Zhejiang University, Kaixuan Road 268, Hangzhou, PR China.
Sun
Yao
Y
Xiao
Chun Lan
CL
Shi
Kai
K
Zhou
Yan Hong
YH
Yu
Jing Quan
JQ
D000975:Antioxidants / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology; D002470:Cell Survival; D002934:Cinnamates / Q000494:pharmacology*; D019662:Cucurbitaceae / Q000187:drug effects* / Q000502:physiology*; D019255:NADPH Oxidases / Q000378:metabolism; D018384:Oxidative Stress; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism; D017382:Reactive Oxygen Species
D000975:Antioxidants; D002934:Cinnamates; D017382:Reactive Oxygen Species; C029010:cinnamic acid; D019255:NADPH Oxidases