1.
Jasmonic Acid Signaling Pathway in Response to Abiotic Stresses in Plants.
Ali, MS, Baek, KH
International journal of molecular sciences. 2020;(2)
Abstract
Plants as immovable organisms sense the stressors in their environment and respond to them by means of dedicated stress response pathways. In response to stress, jasmonates (jasmonic acid, its precursors and derivatives), a class of polyunsaturated fatty acid-derived phytohormones, play crucial roles in several biotic and abiotic stresses. As the major immunity hormone, jasmonates participate in numerous signal transduction pathways, including those of gene networks, regulatory proteins, signaling intermediates, and proteins, enzymes, and molecules that act to protect cells from the toxic effects of abiotic stresses. As cellular hubs for integrating informational cues from the environment, jasmonates play significant roles in alleviating salt stress, drought stress, heavy metal toxicity, micronutrient toxicity, freezing stress, ozone stress, CO2 stress, and light stress. Besides these, jasmonates are involved in several developmental and physiological processes throughout the plant life. In this review, we discuss the biosynthesis and signal transduction pathways of the JAs and the roles of these molecules in the plant responses to abiotic stresses.
2.
Novel markers for high-throughput protoplast-based analyses of phytohormone signaling.
Lehmann, S, Dominguez-Ferreras, A, Huang, WJ, Denby, K, Ntoukakis, V, Schäfer, P
PloS one. 2020;(6):e0234154
Abstract
Phytohormones mediate most diverse processes in plants, ranging from organ development to immune responses. Receptor protein complexes perceive changes in intracellular phytohormone levels and trigger a signaling cascade to effectuate downstream responses. The in planta analysis of elements involved in phytohormone signaling can be achieved through transient expression in mesophyll protoplasts, which are a fast and versatile alternative to generating plant lines that stably express a transgene. While promoter-reporter constructs have been used successfully to identify internal or external factors that change phytohormone signaling, the range of available marker constructs does not meet the potential of the protoplast technique for large scale approaches. The aim of our study was to provide novel markers for phytohormone signaling in the Arabidopsis mesophyll protoplast system. We validated 18 promoter::luciferase constructs towards their phytohormone responsiveness and specificity and suggest an experimental setup for high-throughput analyses. We recommend novel markers for the analysis of auxin, abscisic acid, cytokinin, salicylic acid and jasmonic acid responses that will facilitate future screens for biological elements and environmental stimuli affecting phytohormone signaling.
3.
Sulfated plant peptide hormones.
Kaufmann, C, Sauter, M
Journal of experimental botany. 2019;(16):4267-4277
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Abstract
Sulfated peptides are plant hormones that are active at nanomolar concentrations. The sulfation at one or more tyrosine residues is catalysed by tyrosylprotein sulfotransferase (TPST), which is encoded by a single-copy gene. The sulfate group is provided by the co-substrate 3´-phosphoadenosine 5´-phosphosulfate (PAPS), which links synthesis of sulfated signaling peptides to sulfur metabolism. The precursor proteins share a conserved DY-motif that is implicated in specifying tyrosine sulfation. Several sulfated peptides undergo additional modification such as hydroxylation of proline and glycosylation of hydroxyproline. The modifications render the secreted signaling molecules active and stable. Several sulfated signaling peptides have been shown to be perceived by leucine-rich repeat receptor-like kinases (LRR-RLKs) but have signaling pathways that, for the most part, are yet to be elucidated. Sulfated peptide hormones regulate growth and a wide variety of developmental processes, and intricately modulate immunity to pathogens. While basic research on sulfated peptides has made steady progress, their potential in agricultural and pharmaceutical applications has yet to be explored.
4.
Fungal effectors at the crossroads of phytohormone signaling.
Shen, Q, Liu, Y, Naqvi, NI
Current opinion in microbiology. 2018;:1-6
Abstract
Phytohormone networks are crucial for maintaining the delicate balance between growth and biotic stress responses in plants. Jasmonic acid, salicylic acid, ethylene, and the associated signaling crosstalk are important for pathogen defense; whereas gibberellin and cytokinin function in growth and development in plants. Plant pathogenic fungi have evolved remarkable strategies to manipulate and/or hijack such phytohormone signaling cascades for their own benefit, thus leading to susceptibility and disease in host plants. Interestingly, these hormones are also targeted by fungal endosymbionts and mutualists during beneficial interactions with plants. We highlight current advances in our understanding of the role of fungal effectors in such antagonistic manipulation of phytohormones during pathogenic as well as symbiotic association with plant hosts. In addition to the aforementioned effector-based control, certain phytohormone mimics have recently emerged as a powerful molecular language in fungal manipulation of defense responses and innate immunity in plants.
5.
The nuclear pore complex: a strategic platform for regulating cell signaling.
Gu, Y
The New phytologist. 2018;(1):25-30
Abstract
Contents Summary 25 I Introduction 25 II. Structural organization of the NPC 26 III. The role of NPCs in immune signaling 26 IV. The role of NPCs in hormone signaling 28 V. Conclusions 29 Acknowledgements 29 References 29 SUMMARY Nuclear pore complexes (NPCs) are fundamental components of the eukaryotic cell. They perforate the nuclear envelope and serve as highly selective transport gates that enable bi-directional macromolecule exchange between the nucleus and cytoplasm. Recent studies illustrate that the NPC is not a static structural channel but a flexible environment and strategic player during nuclear signaling. The constitutional and conformational dynamics of the NPC allow it to tailor nucleocytoplasmic transport activities and define specific signaling output in response to various cellular and environmental cues. In this Insight, we review the roles of NPC constituents in immune activation and hormone signaling in plants, and discuss the possible role of the NPC as a legitimate platform for regulating cell signaling.