Physiological and Molecular Mechanism of Nitric Oxide (NO) Involved in Bermudagrass Response to Cold Stress

Abstract

Bermudagrass is widely utilized in parks, lawns, and golf courses. However, cold is a key factor limiting resource use in bermudagrass. Therefore, it is meaningful to study the mechanism of bermudagrass response to cold. Nitric oxide (NO) is a crucial signal molecule with multiple biological functions. Thus, the objective of this study was to investigate whether NO play roles in bermudagrass response to cold. Sodium nitroprusside (SNP) was used as NO donor, while 2-phenyl-4,4,5,5-tetramentylimidazoline-l-oxyl-3-xide (PTIO) plus NG-nitro-L-arginine methyl ester (L-NAME) were applied as NO inhibitor. Wild bermudagrass was subjected to 4 °C in a growth chamber under different treatments (Control, SNP, PTIO + L-NAME). The results indicated lower levels of malondialdehyde (MDA) content and electrolyte leakage (EL), higher value for chlorophyll content, superoxide dismutase (SOD) and peroxidase (POD) activities after SNP treatment than that of PTIO plus L-NAME treatments under cold stress. Analysis of Chlorophyll (Chl) a fluorescence transient displayed that the OJIP transient curve was higher after treatment with SNP than that of treated with PTIO plus L-NAME under cold stress. The values of photosynthetic fluorescence parameters were higher after treatment with SNP than that of treated with PTIO plus L-NAME under cold stress. Expression of cold-responsive genes was altered under cold stress after treated with SNP or PTIO plus L-NAME. In summary, our findings indicated that, as an important strategy to protect bermudagrass against cold stress, NO could maintain the stability of cell membrane, up-regulate the antioxidant enzymes activities, recover process of photosystem II (PSII) and induce the expression of cold-responsive genes.

Mechanisms of Environmental Stress Tolerance in Turfgrass

“…Recently, it was confirmed that the application of signaling molecules could improve the cold tolerance of turfgrass. The foliar application of exogenous melatonin and NO significantly enhanced the cold tolerance of bermudagrass via increasing the photosynthetic efficiency, the enhancement of membrane stability, and the regulation of metabolite contents [154,162,163]. Similarly, after the application of the ABA-mimicking ligand AM1 and Ca 2+ in bermudagrass, the contents of ROS and MDA were reduced, while antioxidant enzyme activity and proline content were increased, which implied an enhancement of cold tolerance level [164].…”

Insights Into the Nitric Oxide Mediated Stress Tolerance in Plants

“…For instance, SNP treatment maintained higher relative water content and reduced ion leakage during drought stress in two turf grass species (Hatamzadeh et al, 2015). Similarly, NO-treated plants maintained high levels of antioxidant enzyme activities and less lipid peroxidation under drought stress in Dendrobium huoshanense and Oryza sativa (Farooq et al, 2009;Fan et al, 2014). Despite reducing the level of oxidative stress, NO also help in maintaining high concentrations of osmotically active solutes and amino acids.…”

“…The major PTMs that are integral to NO signaling include protein S-nitrosylation and tyrosine nitration (Fancy et al, 2017). A number of S-nitrosylated proteins were identified in Arabidopsis thaliana, Brassica juncea, Citrus aurantium, and Zea mays after stress treatment (Mengel et al, 2013;Fan et al, 2014;Fancy et al, 2017). NO-mediated PTMs including nitrosylation, nitration, and carbonylation have been shown to influence ascorbate peroxidase activity under drought (Santisree et al, 2015).…”

“…NO-mediated PTMs including nitrosylation, nitration, and carbonylation have been shown to influence ascorbate peroxidase activity under drought (Santisree et al, 2015). NO mediated S-nitrosylation prevented the inactivation of the antioxidant enzymes in Antiaris toxicaria thereby providing a way to mitigate the H 2 O 2 concentration in plant cells and increasing desiccation tolerance of seeds (Fan et al, 2014;Santisree et al, 2015). Many target signaling components such as redox-associated proteins, the K 1 channel at the guard cell plasma membrane, AtRhobD, salicylic acid-binding protein 3, NPR1, TGA1, and auxin signaling TIR1 (Romero-Puertas et al, 2013;Lindermayr et al, 2010;Terrile et al, 2012) are known to be engaged in NO-mediated PTMs.…”

“…Similarly, proteome profiling revealed 172 downregulated and 76 upregulated proteins in Cicer aritinum leaves (Santisree et al, 2017). Few other studies attempted to understand the proteomic basis of NO mediated stress tolerance (Bai et al, 2011;Sehrawat et al, 2013;Yang et al, 2013;Fan et al, 2014). Nevertheless, high-throughput genomic and proteomic signatures of NO still need to be unfolded to further explore the complexity involved in its signaling under plant stress.…”