Nitric Oxide Emission and Uptake from Higher Plants

Crosstalk among hydrogen sulfide (H2S), nitric oxide (NO) and carbon monoxide (CO) in root-system development and its rhizosphere interactions: A gaseous interactome

Root development in higher plants is achieved by a precise intercellular communication which determines cell fate in the primary embryonic meristem where the gasotransmitters H₂S, NO and CO participate dynamically. Furthermore, the rhizosphere interaction of these molecules with microbial and soil metabolism also affects root development. NO regulates root growth and architecture in association with several other biomolecules like auxin indole-3-acetic acid (IAA), ethylene, jasmonic acid (JA), strigolactones, alkamides and melatonin. The CO-mediated signal transduction pathway in roots is closely linked to the NO-mediated signal cascades. Interestingly, H₂S acts also as an upstream component in IAA and NO-mediated crosstalk during root development. Heme oxygenase (HO) 1 generates CO and functions as a downstream component in H₂S-mediated adventitious rooting and H₂S-CO crosstalk. Likewise, reactive oxygen species (ROS), H₂S and NO crosstalk are important components in the regulation of root architecture. Deciphering these interactions will be a potential biotechnological tool which could provide benefits in crop management in soils, especially under adverse environmental conditions. This review aims to provide a comprehensive update of the complex networks of these gasotransmitters during the development of roots.

A Simple and Useful Method to Apply Exogenous NO Gas to Plant Systems: Bell Pepper Fruits as a Model

Nitric oxide (NO) is involved many physiological plant processes, including germination, growth and development of roots, flower setting and development, senescence, and fruit ripening. In the latter physiological process, NO has been reported to play an opposite role to ethylene. Thus, treatment of fruits with NO may lead to delay ripening independently of whether they are climacteric or nonclimacteric. In many cases different methods have been reported to apply NO to plant systems involving sodium nitroprusside, NONOates, DETANO, or GSNO to investigate physiological and molecular consequences. In this chapter a method to treat plant materials with NO is provided using bell pepper fruits as a model. This method is cheap, free of side effects, and easy to apply since it only requires common chemicals and tools available in any biology laboratory.