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Poly(ADP‐ribose) polymerase in plants affects energy homeostasis, cell death and stress tolerance
Author(s) -
Block Marc De,
Verduyn Christoph,
Brouwer Dirk De,
Cornelissen Marc
Publication year - 2005
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2004.02277.x
Subject(s) - poly adp ribose polymerase , homeostasis , polymerase , programmed cell death , microbiology and biotechnology , biology , chemistry , biochemistry , enzyme , apoptosis
Summary Plants contain two genes that code for poly(ADP‐ribose) polymerase (PARP): parp1 and parp2 . Both PARPs are activated by DNA damage caused by, example reactive oxygen species. Upon activation polymers of ADP‐ribose are synthesized on a range of nuclear enzymes using NAD + as substrate. Here, we show that in plants stresses such as drought, high light and heat activate PARP causing NAD + breakdown and ATP consumption. When the PARP activity is reduced by means of chemical inhibitors or by gene silencing, cell death is inhibited and plants become tolerant to a broad range of abiotic stresses like high light, drought and heat. Plant lines with low poly(ADP‐ribosyl)ation activity maintain under stress conditions their energy homeostasis by reducing NAD + breakdown and consequently energy consumption. The higher energy‐use efficiency avoids the need for a too intense mitochondrial respiration and consequently reduces the formation of reactive oxygen species. From these results it can be concluded that breeding or engineering for a high energy‐use efficiency under stress conditions is a valuable, but until today nearly unexploited, approach to enhance overall stress tolerance of crops.