On the origins of nitric oxide

In vivo role ofArabidopsisarginase in arginine metabolism and abiotic stress response

“…Although changes of AtARGAHs expression had no significant effect on upstream ArticLe AddenduM the production of nitrogen species and reactive oxygen species (ROS). [6][7][8][9][10][11][13][14][15][16][17][18][19][20][21][22][23][24] Among multiple signaling molecules, NO and polyamines might be ideal candidates to integrate several environment stress responses, but the crosstalk of NO and polyamines is complex and needs to be further dissected. 1,4,17 As shown in Figure 1, manipulating the expression of AtARGAHs supplied a good version to investigate the link between NO and polyamines, especially in plant responses to abiotic stress.…”

“…2,3,5 Additionally, although nitric oxide synthase (NOS) has not been cloned in higher plants, similar NOS activity of animals has been detected in many plant species by many research groups. [6][7][8][9][10][11] And it has been confirmed that NO might be generated primarily during the conversion of arginine to citrulline by the NOS, especially in responses to several biotic and abiotic stresses. [6][7][8][9][10][11] Previous research indicated that knockout of Arabidopsis arginase gene resulted in increased NO accumulation, 2 and overexpression of AtARGAH2 conferred increased tolerance to Botrytis cinerea and enhanced callus development during clubroot infection.…”

“…[6][7][8][9][10][11] And it has been confirmed that NO might be generated primarily during the conversion of arginine to citrulline by the NOS, especially in responses to several biotic and abiotic stresses. [6][7][8][9][10][11] Previous research indicated that knockout of Arabidopsis arginase gene resulted in increased NO accumulation, 2 and overexpression of AtARGAH2 conferred increased tolerance to Botrytis cinerea and enhanced callus development during clubroot infection. 3,12 Recently, we investigated the influence of manipulation of AtARGAHs expression on arginine metabolism, as well as plant responses to abiotic stresses including water deficit, salt and freezing.…”

Le monoxyde d’azote

“…Ce constat est à l'origine de controverses quant à l'existence même d'une protéine à activité NOS chez les plantes supé-rieures [8,9]. Signalons que d'autres voies de synthèse de NO, enzymatiques ou non, et utilisant des polyamines ou le nitrite comme substrats, ont également été rapportées [3,4]. Pour l'essentiel, ces voies restent énigmatiques.…”

“…Le NO serait ainsi impliqué dans l'activation ainsi que dans la désensibi-lisation des voies de signalisation mobilisées lors de l'immunité chez les plantes. < Les plantes sont également capables de produire du NO et certains de ses dérivés comme le peroxynitrite et le nitrosoglutathion (GSNO), un réservoir naturel de NO formé entre le glutathion et le NO [3]. D'importants progrès dans la compréhension des fonctions physiologiques du NO chez les plantes ont été accomplis ces dernières années.…”