Differential requirement for NO during ABA-induced stomatal closure in turgid and wilted leaves

• Autor(a) principal: Ribeiro, Dimas M.
• Data de Publicação: 2008
• Outros Autores: Desikan, Radhika, Bright, Jo, Confraria, Ana, Harrison, Judith, Hancock, John T., Barros, Raimundo S., Neill, Steven J., Wilson, Ian D.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1111/j.1365-3040.2008.01906.x; http://www.locus.ufv.br/handle/123456789/13872
• topic: Abscisic acid; Nitric oxide; Stomata; Transpiration; Water stress

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 Ca2+-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.