Contributions of PIP(2)-specific-phospholipase C and free salicylic acid to heat acclimation-induced thermotolerance in pea leaves.
The relationship between the accumulation in endogenous free salicylic acid (SA) induced by heat acclimation (37 degrees C) and the activity of PIP(2)-phospholipase C (PIP(2)-PLC; EC 3.1.4.3) in the plasma membrane fraction was investigated in pea (Pisum sativum L.) leaves. We focused our attention on the hypothesis that positive SA signals induced by heat acclimation may be relayed by PIP(2)-PLC. Heat acclimation induced an abrupt elevation of free SA preceding the activation of PLC toward PIP(2). Immunoblotting indicated a molecular mass with 66.5kDa PLC plays key role in the development of thermotolerance in pea leaves. In addition, some characterizations of PLC toward PIP(2) isolated from pea leaves with two-phase purification containing calcium concentration, pH and a protein concentration were also studied. Neomycin sulfate, a well-known PIP(2)-PLC inhibitor, was employed to access the involvement of PIP(2)-PLC in the acquisition of heat acclimation induced-thermotolerance. We were able to identify a PIP(2)-PLC, which was similar to a conventional PIP(2)-PLC in higher plants, from pea leaves suggesting that PIP(2)-PLC was involved in the signal pathway that leads to the acquisition of heat acclimation induced-thermotolerance. On the basis of these results, we conclude that the involvement of free SA may function as the upstream event in the stimulation of PIP(2)-PLC in response to heat acclimation treatment.
Liu
Hong-Tao
HT
College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Huang
Wei-Dong
WD
Pan
Qiu-Hong
QH
Weng
Fang-Hua
FH
Zhan
Ji-Cheng
JC
Liu
Yan
Y
Wan
Si-Bao
SB
Liu
Yan-Yan
YY
D000064:Acclimatization / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006358:Hot Temperature; D008861:Microsomes / Q000378:metabolism; D009355:Neomycin / Q000494:pharmacology; D018532:Pisum sativum / Q000033:anatomy & histology / Q000201:enzymology / Q000378:metabolism*; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000502:physiology*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction
D004791:Enzyme Inhibitors; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D010650:Phenylalanine Ammonia-Lyase; D009355:Neomycin; D020156:Salicylic Acid