Differential induction of oxylipin pathway in potato and tobacco cells by bacterial and oomycete elicitors

Abstract

Potato and tobacco cells are differentially suited to study oxylipin pathway and elicitor-induced responses. Synthesis of oxylipins via the lipoxygenase (LOX) pathway provides plant cells with an important class of signaling molecules, related to plant stress responses and innate immunity. The aim of this study was to evaluate the induction of LOX pathway in tobacco and potato cells induced by a concentrated culture filtrate (CCF) from Phytophthora infestans and lipopolysaccharide (LPS) from Pectobacterium atrosepticum. Oxylipin activation was evaluated by the measurement of LOX activity and metabolite quantification. The basal levels of oxylipins and fatty acids showed that potato cells contained higher amounts of linoleic (LA), linolenic (LnA) and stearic acids than tobacco cells. The major oxylipin in potato cells, 9(S),10(S),11(R)-trihydroxy-12(Z),15(Z)-octadecadienoic acid (9,10,11-THOD), was not detected in tobacco cells. CCF induced a sharp increase of LA and LnA at 8 h in tobacco cells. In contrast they decreased in potato cells. In CCF-treated tobacco cells, colneleic acid increased up to 24 h, colnelenic acid and 9(S)-hydroxyoctadecatrienoic acid (9(S)-HOT) increased up to 16 h. In potato cells, only colneleic acid increased slightly until 16 h. A differential induction of LOX activity was measured in both cells treated by CCF. With LPS treatment, only 9,10,11-THOD accumulation was significantly induced at 16 h in potato cells. Fatty acids were constant in tobacco but decreased in potato cells over the studied time period. These results showed that the two elicitors were differently perceived by the two Solanaceae and that oxylipin pathway is strongly induced in tobacco with the CCF. They also revealed that elicitor-induced responses depended on both cell culture and elicitor.

Hormone signalling pathways are differentially involved in quantitative resistance of potato to Phytophthora infestans

“…PAMPs are conserved pathogen‐derived molecules that are essential to the pathogen's survival or lifestyle (Gómez‐Gómez, ) and trigger a number of general defence responses, including the biosynthesis of reactive oxygen species (ROS), cell wall reinforcement (callose deposition) and induction of defence gene expression (Garcia‐Brugger et al ., ; Ingle et al ., ). They also activate several metabolic pathways leading to the biosynthesis of phenylpropanoids (Kröner et al ., ), oxylipins (Saubeau et al ., ) or sesquiterpenoids (Yoshioka et al ., ).…”

“…It has been previously demonstrated that a recently characterized concentrated culture filtrate (CCF) of P. infestans (Saubeau et al, 2014) can be considered as a PAMP (Desender et al, 2006). The CCF primes defence reactions in potato cell suspensions (Val et al, 2008) and triggers accumulation of various oxylipins in tobacco and potato cell suspensions (Saubeau et al, 2013). It was also shown that, in five potato genotypes with different levels of quantitative resistance to P. infestans, the CCF also induced the phenylpropanoid pathway (Kr€ oner et al, 2011).…”

Deciphering the dual effect of lipopolysaccharides from plant pathogenicPectobacterium

“…27 Interestingly, the induction of PAL1 transcript seemed to be correlated with the LPS-induced ROS generation, since PAL1 transcription after treatment with LPS Pcc was larger at 1 h than at 3 h on the opposite of what observed with LPS P. aeruginosa . Tiron, a scavenger of ROS, as well as DPI were able to decrease ROS generation and the LPS-induced PAL1 transcription.…”

“…26 The fact that LPS induced variable cellular responses can be attributed to LPS preparations, plants and cell types used and reflect the ability of particular plants to recognize structural features within LPS that are not widely conserved. 14,27 [28][29][30] Also, depending on animal model and cell type, LPS could acts as mechanism of protection and preventing cell death, 31 or virulence factors by favoring the escape from the innate immune system. 32 Thus, LPS could have complex and different roles in plants as well as in animals.…”

Protection against bacterial soft rot by olive extracts is related to general defence induction in potato tubers

“…This enzyme was chosen as a general defence marker governing diverse defence pathways (oxylipins, phenylpropanoids, etc. ), triggered either directly or through hormonal regulation, and involved in soft rot restriction in potato (Desender et al, 2006;Kr€ oner et al, 2011Kr€ oner et al, , 2012Saubeau et al, 2013Saubeau et al, , 2016.…”