Nitric Oxide Signalling in Plants

Abstract

Nitric oxide (NO) is a small simple molecule, but one which is instrumental in cell signalling in a range of organisms including plants. It is a gas, often found in the form of a radical. It is produced in cells in an orchestrated manner, usually by dedicated enzymes and often following stress. It leads to numerous responses. In plants it is involved in seed germination, seedling development, stomatal responses, senescence and protection against pathogens, so is an instrumental signalling molecule used throughout the life of the plant. Responses to NO may involve the generation of other signalling molecules such as cGMP or the covalent modification of proteins in a process known as S‐nitrosation. However, it should be noted that NO signalling will not be isolated in the cell and NO will impinge on other signalling pathways, such as those involving reactive oxygen species. Therefore, NO should be considered as part of a suite of signalling components which enable plants to thrive and survive. Key Concepts NO, along with reactive oxygen species (ROS), is produced by plants during normal growth and development and its production is often increased as part of stress responses. NO is involved in a range of plant processes including pollen recognition and germination, seed germination, senescence, pathogen attack, gravitropism and stomatal responses. NO can be generated enzymatically or nonenzymatically in cells. Nitrate reductase is a key enzyme which generates NO. NO may lead to increases in cGMP levels in cells. NO, or downstream products, may lead to modification of proteins and hence their activities. Removal of NO is important for signalling. The signalling involving NO will affect, and be affected by, other signalling pathways including those involving reactive oxygen species and hydrogen sulfide.

Nitric oxide is involved in the brassinolide-induced adventitious root development in cucumber

“…Nitric oxide (NO), a ubiquitous signal molecule, plays important roles in different plant tissues and participates in a variety of physiological processes [13]. Many researchers observed that NO induced root development in Zea mays [14], and it also induced seed germination, seedling development, stomatal responses, senescence, flowering and protection against pathogens in different plant species [15][16][17][18][19][20]. NO production in plants has two pathways, including enzymatic pathway and non-enzymatic pathway.…”

Nitric oxide is involved in the brassinolide-induced adventitious root development in cucumber

“…Nitric oxide (NO), a ubiquitous signal molecule, plays important roles in different plant tissues and participates in a variety of physiological processes [13]. Many researchers observed that NO induced root development in Zea mays [14], and it also induced seed germination, seedling development, stomatal responses, senescence, flowering and protection against pathogens in different plant species [15][16][17][18][19][20]. NO production in plants has two pathways, including enzymatic pathway and nonenzymatic pathway.…”

Effect of nitric oxide fumigation on microorganisms and quality of dried apricots during storage

“…Nitric oxide (NO) acts as a key regulator in the expression of various genes involved in plant life activities (Arasimowicz & Florysza-Kwieczorek, 2007;Hancock et al, 2017) that not only affects a series of physiological processes but also plays a crucial role in signal transduction (Domingos et al, 2015). Liu (2016), Liu et al (2017) found that NO fumigation used for pest control could improve the postharvest quality of fresh products.…”