Cryptogein, a fungal elicitor, remodels the phenylpropanoid metabolism of tobacco cell suspension cultures in a calcium-dependent manner.
Plant cells use calcium-based signalling pathways to transduce biotic and/or abiotic stimuli into adaptive responses. However, little is known about the coupling between calcium signalling, transcriptional regulation and the downstream biochemical processes. To understand these relationships better, we challenged tobacco BY-2 cells with cryptogein and evaluated how calcium transients (monitored through the calcium sensor aequorin) impact (1) transcript levels of phenylpropanoid genes (assessed by RT-qPCR); and (2) derived-phenolic compounds (analysed by mass spectrometry). Most genes of the phenylpropanoid pathway were up-regulated by cryptogein and cell wall-bound phenolic compounds accumulated (mainly 5-hydroxyferulic acid). The accumulation of both transcripts and phenolics was calcium-dependent. The transcriptional regulation of phenylpropanoid genes was correlated in a non-linear manner with stimulus intensity and with components of the cryptogein-induced calcium signature. In addition, calmodulin inhibitors increased the sensitivity of cells to low concentrations of cryptogein. These results led us to propose a model of coupling between the cryptogein signal, calcium signalling and the transcriptional response, exerting control of transcription through the coordinated action of two decoding modules exerting opposite effects.
Université de Toulouse, UPS, UMR 5546 Surfaces Cellulaires et Signalisation chez les Végétaux, BP 42617, F-31326, Castanet-Tolosan, France.
Nicolas
N
Amelot
Audrey
A
Carrouche
Saïda
S
Danoun
Stéphane
S
Bourque
Jacques
J
Haiech
Alain
A
Pugin
Raoul
R
Ranjeva
Jacqueline
J
Grima-Pettenati
Christian
C
Mazars
Christian
C
Briere
D020418:Algal Proteins / Q000378:metabolism* / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002478:Cells, Cultured; D003373:Coumaric Acids / Q000378:metabolism; D005656:Fungal Proteins; D018506:Gene Expression Regulation, Plant; D013058:Mass Spectrometry; D057865:Plant Immunity; D030821:Plants, Genetically Modified; D025341:Principal Component Analysis; D020005:Propanols / Q000378:metabolism*; D011422:Propionates; D018749:RNA, Plant; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D014026:Nicotiana / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D020418:Algal Proteins; D002147:Calmodulin; D003373:Coumaric Acids; D005656:Fungal Proteins; D020005:Propanols; D011422:Propionates; D018749:RNA, Plant; C061032:cryptogein protein, Phytophthora cryptogea; C439395:1-phenylpropanol; C071744:5-hydroxyferulic acid; C004999:ferulic acid; C495469:p-coumaric acid; D002118:Calcium