Diverse functional interactions between nitric oxide and abscisic acid in plant development and responses to stress

[EN] The extensive support for abscisic acid (ABA) involvement in the complex regulatory networks controlling stress responses and development in plants contrasts with the relatively recent role assigned to nitric oxide (NO). Because treatment with exogenous ABA leads to enhanced production of NO, it has been widely considered that NO participates downstream of ABA in controlling processes such as stomata movement, seed dormancy, and germination. However, data on leaf senescence and responses to stress suggest that the functional interaction between ABA and NO is more complex than previously thought, including not only cooperation but also antagonism. The functional relationship is probably determined by several factors including the time- and place-dependent pattern of accumulation of both molecules, the threshold levels, and the regulatory factors important for perception. These factors will determine the actions exerted by each regulator. Here, several examples of well-documented functional interactions between NO and ABA are analysed in light of the most recent reported data on seed dormancy and germination, stomata movements, leaf senescence, and responses to abiotic and biotic stresses This work was supported by MICINN (Spain) grants BIO2011-27526 and CONSOLIDER CSD2007-00057 to JL and postdoctoral contracts to MCC and AC. RM was funded by a pre-doctoral fellowship of the FPU Program from MEC (Spain). We thank Michael Holdsworth (University of Nottingham, UK) for critical reading of this manuscript and for his helpful comments and corrections. We would also like to express our appreciation for all the contributions reported in this research area, and particularly to those researchers who have not been cited in this review because of the limitations of manuscript length. Leon Ramos, J.; Castillo López Del Toro, MC.; Coego González, A.; Lozano Juste, J.; Mir Moreno, R. (2014). Diverse functional interactions between nitric oxide and abscisic acid in plant development and responses to stress. Journal of Experimental Botany. 65(4):907-921. https://doi.org/10.1093/jxb/ert454 ALBORESI, A., GESTIN, C., LEYDECKER, M.-T., BEDU, M., MEYER, C., & TRUONG, H.-N. (2005). Nitrate, a signal relieving seed dormancy in Arabidopsis. Plant, Cell and Environment, 28(4), 500-512. doi:10.1111/j.1365-3040.2005.01292.x Asai, S., & Yoshioka, H. (2009). Nitric Oxide as a Partner of Reactive Oxygen Species Participates in Disease Resistance to Necrotrophic Pathogen Botrytis cin