Patrice Thuleau

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Cadmium is suspected to exert its toxic action on cells through oxidative damage. However, the transition metal is unable to directly generate reactive oxygen species (ROS) via redox reactions with molecular oxygen in a biological environment. Here, we show that bright yellow-2 (BY-2) tobacco cells exposed to millimolar concentrations of CdCl(2) developed(More)
Using Nicotiana plumbaginifolia constitutively expressing the recombinant bioluminescent calcium indicator, aequorin, it has been previously demonstrated that plant cells react to cold-shock by an immediate rise in cytosolic calcium. Such an opportune system has been exploited to address the regulatory pathway involved in the calcium response. For this(More)
Numerous biological assays and pharmacological studies on various higher plant tissues have led to the suggestion that voltage-dependent plasma membrane Ca2+ channels play prominent roles in initiating signal transduction processes during plant growth and development. However, to date no direct evidence has been obtained for the existence of such(More)
In eukaryotic cells, sphingoid long chain bases (LCBs) such as sphingosine or phytosphingosine (PHS) behave as second messengers involved in various processes including programmed cell death (PCD). In plants, induction of PCD by LCBs has now been described, but the signalling pathway is still enigmatic. Using Arabidopsis, we identify new key steps in this(More)
Depolarization-activated plasma membrane calcium channels have been suggested to play prominent roles in signal perception and transduction processes during growth and development of higher plants. The existence of such channels has recently been established in higher plant cells. However, patch-clamp experiments have shown that their activity is very low(More)
Calcium channels have been suggested to play a major role in the initiation of a large number of signal transduction processes in higher plant cells. However, molecular components of higher plant Ca2+ channels remain unidentified to date. Calcium channel blockers of the phenylalkylamine family and bepridil specifically inhibit Ca2+ influx into carrot(More)
Plasma membrane-bound voltage-dependent calcium channels may couple the perception of an initial stimulus to a regulated pathway for calcium influx. The activities of these channels have been shown to be very low and highly unstable but may be recruited by large-predepolarizing pulses, according to a process referred to as recruitment. By combining(More)
Calcium channel blockers of the phenylalkylamine family bind specifically to membranes and inhibit calcium uptake in carrot protoplast. LU 49888, an azido derivative of phenylalkylamine, behaves as its unmodified homolog in terms of affinity and specificity and therefore allows us to probe the receptor by photoaffinity labeling. Upon UV irradiation, a(More)
Calcium and Reactive Oxygen Species (ROS) are acknowledged as crucial second messengers involved in the response to various biotic and abiotic stresses. However, it is still not clear how these two compounds can play a role in different signaling pathways leading the plant to a variety of processes such as root development or defense against pathogens.(More)