Differential requirement for NO during ABA-induced stomatal closure in turgid and wilted leaves.
Abscisic acid (ABA)-induced stomatal closure is mediated by a complex, guard cell signalling network involving nitric oxide (NO) as a key intermediate. However, there is a lack of information concerning the role of NO in the ABA-enhanced stomatal closure seen in dehydrated plants. The data herein demonstrate that, while nitrate reductase (NR)1-mediated NO generation is required for the ABA-induced closure of stomata in turgid leaves, it is not required for ABA-enhanced stomatal closure under conditions leading to rapid dehydration. The results also show that NO signalling in the guard cells of turgid leaves requires the ABA-signalling pathway to be both capable of function and active. The alignment of this NO signalling with guard cell Ca(2+)-dependent/independent ABA signalling is discussed. The data also highlight a physiological role for NO signalling in turgid leaves and show that stomatal closure during the light-to-dark transition requires NR1-mediated NO generation and signalling.
Ribeiro
Dimas M
DM
Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Minas Gerais, Brazil.
Desikan
Radhika
R
Bright
Jo
J
Confraria
Ana
A
Harrison
Judith
J
Hancock
John T
JT
Barros
Raimundo S
RS
Neill
Steven J
SJ
Wilson
Ian D
ID
D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D029681:Arabidopsis Proteins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D008027:Light; D009154:Mutation; D050901:Nitrate Reductase / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism*; D054046:Plant Stomata / Q000378:metabolism* / Q000502:physiology; D014867:Water / Q000502:physiology*
D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D014867:Water; D009569:Nitric Oxide; D000040:Abscisic Acid; D050901:Nitrate Reductase; D002118:Calcium