INVESTIGADORES
TEN HAVE Arjen
congresos y reuniones científicas
Título:
Nitric oxide and phosphatidic acid crosstalk in (a)biotic stress.
Autor/es:
GONORAZKY MG; DISTÉFANO A.M; GUZZO ML; SCUFFI, D; ABD-EL HALIEM A; JOOSTEN MHAJ; RAMIREZ L; VALIÑAS, M; TEN HAVE A; D'AMBROSSIO JM; LAMATTINA L; GARCIA-MATA C; LAXALT AM
Lugar:
Galveston TX
Reunión:
Congreso; Gordon Research Conferences, Plant Lipids: Structure, Metabolism & Function.; 2013
Institución organizadora:
GRC
Resumen:
P { margin-bottom: 0.08in; }
Nitric Oxide (NO) is an
important redox based regulator of cell physiology and is involved in
many signalling processes in plants.
The precise mechanism of how NO interacts with or activates different
targets is still poorly understood. NO can activate signalling
pathways that implicate cGMP, cADPR, Ca2+,
ion channels and protein kinases such as MAPKs and CDPKs.
The polar lipid phosphatidic
acid (PA) is another molecule involved in plant signalling. Two
enzymatic pathways produce PA, phospholipase D (PLD) and
phospholipase C (PLC) in concerted action with diacylglycerol kinase
(DGK). PA affects ion channels, NADPH oxidase and protein kinases and
phosphatases.
NO and PA have been
independently regarded as general and multifunctional signalling
molecules in plants. Since both share common effectors we
hypothesized NO and PA participate in the same signalling pathway.
Results obtained in our laboratory revealed that NO can induce PA
formation during
plant-defense responses and stomatal closure.
NO is involved in the plant
defense response of a growing list of plant-pathogen interactions.
Xylanase is a fungal
elicitor that activates a rapid PA production in tomato cells via two
enzymatic pathways, PLD and PLC/DGK (van der Luit et al., 2000). We
have demonstrated that the fungal elicitor xylanase requires NO to
rapidly activate the PLC pathway and downstream defence responses in
tomato cell suspensions and that S-nitrosylation is the NO
post-translational modification involved in the PLC activation
(Laxalt et al., 2007; Lanteri et al., 2011). We are currently
silencing tomato PLCs in order to elucidate which one is the PLCs are
activated by NO in xylanase induced PLC pathway.
ii) NO
reduces transpirational water loss by inducing stomatal closure
(Garcia-Mata and
Lamattina 2001). PLC
and PLD activities are required for NO-induced PA formation and
stomatal closure in Vicia
faba guard cells
(Distéfano et al., 2008). NO
increases PLD activity that is required for NO-induced stomatal
closure. Arabidopsis has
12 PLD genes and only two AtPLDs isoenzymes, PLDα1 and PLDδ, have
been related to drought and dehydration stress. Recent evidences
indicate that PLDα1 is upstream of NO production. However,
we showed that PLD
activation is downstream NO. Thus we hypothesized that PLDd could be
activated by NO. PLDδ
mRNA levels increases
in ABA-treated guard cells. PLDδ
knock-out plants (pldδ)
failed to close the stomata in response to NO. ABA signalling in
guard cells involves H2O2
and NO production. pldδ
guard cells produced similar NO and H2O2
levels as the wild type in response to ABA. However, ABA- or
H2O2-induced
stomatal closure was impaired in pldplants (Distéfano et
al., 2012). Unexpectedly,
pldδ plants
were more tolerant to drought. These
data indicates that PLDδ is downstream of NO and H2O2
in ABA-induced stomatal closure and participates in drought stress.
We are currently studying how does NO regulates PLDd activity.