The effects of exogenous putrescine on sex-specific responses of Populus cathayana to copper stress.
We used the dioecious tree, Populus cathayana, as a model species to study plants' physiological and biochemical responses to copper (Cu) stress, exogenous putrescine (Put) treatment and their interaction. Although males accumulated higher Cu concentrations in leaves than did females under Cu stress, they did not suffer more damage than females, as reflected by changes in gas exchange, pigment contents, membrane lipid peroxidation (thiobarbituric acid reactive substances, TBARS) and protein oxidation (carbonyl). Higher Cu tolerance of males was correlated with a higher H2O2 scavenging ability and proline responses, and a better maintenance of non-protein thiols (NP-SHs) and spermine (Spm) contents. We also discovered that mitigation effects of exogenous Put on Cu stress occurred, as visible as a recovery of the total chlorophyll content, and lower TBARS and carbonyl under interaction treatment when compared to Cu stress alone. Exogenous Put decreased the Cu concentration in leaves of both sexes, but to different degrees. Such effects of exogenous Put suggested that Put may play important roles in the stabilization of membrane integrity and protein structures, and it may modulate the uptake and transportation of Cu. Our results indicated that (1) males are more tolerant to Cu stress than females; (2) Put could mitigate Cu toxicity in P. cathayana, but to a different degree in males and females; (3) males are better candidates than females for Cu extraction and phytoremediation.
Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu 611130, China.
Lianghua
L
Chen
Ling
L
Wang
Fugui
F
Chen
Helena
H
Korpelainen
Chunyang
C
Li
D002734:Chlorophyll / Q000378:metabolism; D003300:Copper / Q000032:analysis / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D004798:Enzymes / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D010858:Pigmentation / Q000187:drug effects; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology; D011073:Polyamines / Q000032:analysis; D032107:Populus / Q000187:drug effects* / Q000502:physiology; D011392:Proline / Q000032:analysis; D011700:Putrescine / Q000633:toxicity*; D013312:Stress, Physiological / Q000187:drug effects*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D004798:Enzymes; D011073:Polyamines; D017392:Thiobarbituric Acid Reactive Substances; D002734:Chlorophyll; D003300:Copper; D011392:Proline; D006861:Hydrogen Peroxide; D011700:Putrescine
Copper stress; Dioecy; Phytoremediation; Polyamine; Poplar; Putrescine