Nitric Oxide Signalling in Yeast.
Astuti Rika I,Nasuno Ryo,Takagi Hiroshi
Advances in microbial physiology
Nitric oxide (NO) is a cellular signalling molecule widely conserved among organisms, including microorganisms such as bacteria, yeasts, and fungi, and higher eukaryotes such as plants and mammals. NO is mainly produced by the activities of NO synthase (NOS) or nitrite reductase (NIR). There are several NO detoxification systems, including NO dioxygenase (NOD) and S-nitrosoglutathione reductase (GSNOR). NO homeostasis, based on the balance between NO synthesis and degradation, is important for regulating its physiological functions, since an excess of NO causes nitrosative stress due to the high reactivity of NO and NO-derived compounds. In yeast, NO may be involved in stress responses, but the role of NO and the mechanism underlying NO signalling are poorly understood due to the lack of mammalian NOS orthologs in the yeast genome. NOS and NIR activities have been observed in yeast cells, but the gene-encoding NOS and the mechanism by which NO production is catalysed by NIR remain unclear. On the other hand, yeast cells employ NOD and GSNOR to maintain intracellular redox balance following endogenous NO production, treatment with exogenous NO, or exposure to environmental stresses. This article reviews NO metabolism (synthesis, degradation) and its regulation in yeast. The physiological roles of NO in yeast, including the oxidative stress response, are also discussed. Such investigations into NO signalling are essential for understanding how NO modulates the genetics and physiology of yeast. In addition to being responsible for the pathology and pharmacology of various degenerative diseases, NO signalling may be a potential target for the construction and engineering of industrial yeast strains.
[Research progress in nitric oxide biosynthesis, degradation and function in fungi].
Chen Yiduo,Zhang Zhen,Jiang Hua,Wang Yanli,Sun Guochang
Wei sheng wu xue bao = Acta microbiologica Sinica
Nitric oxide is a highly reactive molecule with dichotomous regulatory roles in numerous physiological and pathological events. It has been recognized as an intra-and inter-cellular signaling molecule in animals, plants and microorganisms. Recent research data indicate that fungi are capable of synthesizing nitric oxide. Appropriate amounts of nitric oxide play important biological roles in fungal cells. However, excessive amounts of nitric oxide will damage cells and evoke apoptosis. Nitric oxide regulates the synthesis of cGMP, an important intracellular secondary messenger molecule, involved in the control of a variety of signal transduction pathways in fungal cells. Nitric oxide regulates the cellular development, morphogenesis, sporulation, spore germination, reproduction and apoptosis in fungi. Nitric oxide affects the physiological function of fungi throughout the life cycle. Although the mechanism of nitric oxide in plants and animals has been widely studied, there are limited reports about nitric oxide in fungi; and further investigation is needed to illustrate the nitric oxide synthesis, degradation pathways and the mechanism of signal transduction in the fungal system.
Nitric oxide signalling in plant interactions with pathogenic fungi and oomycetes.
Jedelská Tereza,Luhová Lenka,Petřivalský Marek
Journal of experimental botany
Nitric oxide (NO) and reactive nitrogen species have emerged as crucial signalling and regulatory molecules across all organisms. In plants, fungi, and fungi-like oomycetes, NO is involved in the regulation of multiple processes during their growth, development, reproduction, responses to the external environment, and biotic interactions. It has become evident that NO is produced and used as a signalling and defence cue by both partners in multiple forms of plant interactions with their microbial counterparts, ranging from symbiotic to pathogenic modes. This review summarizes current knowledge on the role of NO in plant-pathogen interactions, focused on biotrophic, necrotrophic, and hemibiotrophic fungi and oomycetes. Actual advances and gaps in the identification of NO sources and fate in plant and pathogen cells are discussed. We review the decisive role of time- and site-specific NO production in germination, oriented growth, and active penetration by filamentous pathogens of the host tissues, as well in pathogen recognition, and defence activation in plants. Distinct functions of NO in diverse interactions of host plants with fungal and oomycete pathogens of different lifestyles are highlighted, where NO in interplay with reactive oxygen species governs successful plant colonization, cell death, and establishment of resistance.
Nitric oxide in plant-fungal interactions.
Martínez-Medina Ainhoa,Pescador Leyre,Terrón-Camero Laura C,Pozo María J,Romero-Puertas María C
Journal of experimental botany
Whilst many interactions with fungi are detrimental for plants, others are beneficial and result in improved growth and stress tolerance. Thus, plants have evolved sophisticated mechanisms to restrict pathogenic interactions while promoting mutualistic relationships. Numerous studies have demonstrated the importance of nitric oxide (NO) in the regulation of plant defence against fungal pathogens. NO triggers a reprograming of defence-related gene expression, the production of secondary metabolites with antimicrobial properties, and the hypersensitive response. More recent studies have shown a regulatory role of NO during the establishment of plant-fungal mutualistic associations from the early stages of the interaction. Indeed, NO has been recently shown to be produced by the plant after the recognition of root fungal symbionts, and to be required for the optimal control of mycorrhizal symbiosis. Although studies dealing with the function of NO in plant-fungal mutualistic associations are still scarce, experimental data indicate that different regulation patterns and functions for NO exist between plant interactions with pathogenic and mutualistic fungi. Here, we review recent progress in determining the functions of NO in plant-fungal interactions, and try to identify common and differential patterns related to pathogenic and mutualistic associations, and their impacts on plant health.