Action of aluminum, novel TPC1-type channel inhibitor, against salicylate-induced and cold-shock-induced calcium influx in tobacco BY-2 cells.
Previously, effect of Al ions on calcium signaling was assessed in tobacco cells expressing a Ca2+-monitoring luminescent protein, aequorin and a newly isolated putative plant Ca2+ channel protein from Arabidopsis thaliana, AtTPC1 (two-pore channel 1). TPC1 channels were shown to be the only channel known to be sensitive to Al and they are responsive to reactive oxygen species and cryptogein, a fungal elicitor protein. Thus, involvement of TPC1 channels in calcium signaling leading to development of plant defense mechanism has been suggested. Then, the use of Al as a specific inhibitor of TPC1-type plant calcium channels has been proposed. Here, using transgenic tobacco BY-2 cells expressing aequorin, we report on the evidence in support of the involvement of Al-sensitive signaling pathway requiring TPC1-type channel-dependent Ca2+ influx in response to salicylic acid, a key plant defense-inducing agent, but not to an elicitor prepared from the cell wall of rice blast disease fungus Magnaporthe grisea. In addition, involvement of Al-sensitive Ca2+ channels in response to cold shock was also tested. The data suggested that the elicitor used here induces the Ca2+ influx via Al-insensitive path, while salicylic acid and cold-shock-stimulate the influx of Ca2+ via Al-sensitive mechanism.
Lin
Cun
C
Graduate School of Environmental Engineering, The University of Kitakyushu, Kitakyushu 808-0135, Japan.
Yu
Yawei
Y
Kadono
Takashi
T
Iwata
Michiaki
M
Umemura
Kenji
K
Furuichi
Takuya
T
Kuse
Masaki
M
Isobe
Minoru
M
Yamamoto
Yoko
Y
Matsumoto
Hideaki
H
Yoshizuka
Kazuharu
K
Kawano
Tomonori
T
D000331:Aequorin / Q000235:genetics / Q000378:metabolism; D000535:Aluminum / Q000494:pharmacology*; D015220:Calcium Channels; D020013:Calcium Signaling / Q000187:drug effects*; D027682:Cation Transport Proteins / Q000037:antagonists & inhibitors*; D003080:Cold Temperature; D007473:Ion Channels / Q000037:antagonists & inhibitors*; D020082:Magnaporthe / Q000737:chemistry; D008954:Models, Biological; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000097903:Two-Pore Channels
D000331:Aequorin; D000535:Aluminum; D015220:Calcium Channels; D027682:Cation Transport Proteins; D007473:Ion Channels; D011994:Recombinant Proteins; D020156:Salicylic Acid; C407357:TPCN1 protein, human; D000097903:Two-Pore Channels