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Melatonin is a well-known signaling molecule that mediates a range of physiological activities and various stress reactions in plants. We comprehensively tested the effect of melatonin on the development of root hairs and glandular trichomes and found that melatonin pretreatment of tobacco seeds significantly increased the length of root hairs. Furthermore, melatonin-treated tobacco exhibited significantly higher density of trichomes and larger glandular heads on long-stalk glandular trichomes than untreated plants, which resulted in enhanced secretion in glandular trichomes. Exogenous melatonin enhanced the aphid resistance of plants by facilitating the accumulation of cembranoids in the glandular trichomes and alleviated cadmium toxicity by increasing the Cd-exudation capacity of long glandular trichomes. Metabolic analysis indicated that the contents of 108 metabolites significantly changed upon melatonin treatment, with the contents of those that are directly/indirectly involved in melatonin metabolism changing the most. Further, KEGG pathway analysis suggested that the metabolic pathways of amino acids, reducing sugar, secondary metabolites, indole alkaloid biosynthesis, purine, pyrimidine, and ABC transporters were greatly influenced by exogenous melatonin application. Moreover, metabolisms of melatonin-related antioxidants and pyrimidine nucleoside antibiotics were enhanced after melatonin treatment. Melatonin improved tobacco resistance to high salinity, drought, and extreme temperature stresses, as indicated by improved photosynthetic and antioxidant capacities in treated vs. untreated plants. This study lays a foundation for the comprehensive application of melatonin to increase the stress tolerance of plants. [Display omitted] • Melatonin promoted the development of root hairs and glandular trichomes. • Exogenous melatonin enhanced aphid resistance of tobacco plants. • Melatonin facilitated the secretion of glandular trichomes. • Melatonin treatment alleviated cadmium toxicity in tobacco plants. • Exogenous melatonin enhanced the metabolism of some antioxidants. [ABSTRACT FROM AUTHOR]

Phytoremediation is an essential technique for mines' ecological restoration. Modifiers addition can alleviate the stress of heavy metals to plants and enhanced remediation efficiency. Herein, spent mushroom compost (SMC) and calcium carbonate (CaCO 3) were added to lead-zinc mine tailings to reveal the mechanism of Macleaya cordata adaptive to heavy metals stress. Pot experiments were conducted in 100% tailing (T), 90% tailing + 5% SMC + 5% CaCO 3 (T+), and 100% natural soil (NS). The results indicate that SMC and CaCO 3 amendments could improve the structure and fertility of tailings, and promote the growth of M. cordata , increase the content of heavy metals accumulated in plants, enhance the synthesis of chlorophyll and increas the content of soluble protein in leaves; enhance the activities of antioxidase, that can protectcelluar components from oxidative damage. Moreover, most of Pb, Zn, and Cd existed in the cell wall and soluble components, adding SMC and CaCO 3 could promote the conversion of Pb, Zn, and Cd to chemical forms with less toxicity and migratory capability. The results of transmission electron microscopy (TEM) and Fourier transform infrared spectrometer (FTIR) showed that SMC and CaCO 3 could protect the structural integrity of cells and increase the contents of –OH, –COOH functional groups that can bind to heavy metals in cells. The addition of SMC and CaCO 3 can alleviate the stress of heavy metals on M. cordata , enhancing its adaptability to heavy metals and phytoremediation capacity. • The SMC and CaCO 3 amendments could strengthen the phytoremediation potential. • Fixation of cell wall play an important role in reducing the stress of Pb, Zn and Cd. • Antioxidant enzyme system effectively reduce the stress of Pb, Zn and Cd to plant. • The SMC and CaCO 3 amendments could alleviate the damage of cell structure. [ABSTRACT FROM AUTHOR]

[Display omitted] In the biological environment, mineral crystals exquisitely controlled by biomacromolecules often show intricate hierarchical structures and superior mechanical properties. Among these biominerals, spicules, hybrid silica/protein superstructures serving as skeletal elements in demosponges, represent an excellent example for motivating the synthesis of silica materials. Herein, by designing sequence-defined peptoids containing side chains with a strong binding to silica, we demonstrated that self-assembly of these peptoids into fiber structures enables the mimicking of both biocatalytic and templating functions of silicatein filaments for the formation of silica fibers at near-neutral pH and ambient temperature. We further showed that the presence of amino groups is significant for the nucleation of silica on self-assembled peptoid nanofibers. Molecular dynamics simulation further confirmed that having silica-binding of amino side chains is critical for self-assembled peptoid fibers in triggering silica formation. We demonstrated that tuning inter-peptoid interactions by varying carboxyl and amino side chains significantly influences the assembly kinetics and final morphologies of peptoid assemblies as scaffolds for directing silica mineralization to form silica spheres, fibers, and sheets. The formation of silica shell on peptoid fibers increased the mechanical property of peptoid hydrogel materials by nearly 1000-fold, highlighting the great potential of using silicification to enhance the mechanical property of hydrogel materials for applications including tissue engineering. Since peptoids are highly robust and programmable, we expect that self-assembly of peptoids containing solid-binding side chains into hierarchical materials opens new opportunities in the design and synthesis of highly tunable scaffolds that direct the formation of composite nanomaterials. [ABSTRACT FROM AUTHOR]

• An algorithm is designed to reduce the network blocking rate. • Markov Decision Process based state transfer is provided for online RMSA in real-time. • Offline Deep Q-Network based algorithm is provided to get a well-trained Q-network helping the RMSA state transfer. • The experience priority replay mechanism and Sumtree are introduced to speed up Deep Q-Network training. The continuous growth of the network communication demand puts higher requirements on the network infrastructures. The elastic optical network (EON) has great potential to support the continued demands for communication bandwidth. Efficient use of bandwidth resources of EON has been particularly important to alleviate network blocking, which depends on routing, modulation, and spectrum allocation processes (RMSA). However, the time-varying states of EON caused by the uncertainty of future demands make it a lot tougher to realize the online RMSA in real time. To solve the above problem, this paper proposes a kind of Deep Q Network (DQN) algorithm with prioritized experience replay mechanism to perform the RMSA process in real-time. The proposed algorithm includes two parts. One is the Markov Decision Process (MDP) based state transfer for online RMSA by a trained Q-network. The other is an offline DQN-based algorithm for getting a trained Q-network to help the decision-making of RMSA state transfer, where the experience priority replay mechanism and Sumtree are introduced to speed up DQN training. Simulation results show that compared with the traditional Deep Q Network algorithm, the proposed algorithm nearly doubles the Q-network training speed. And compared with the traditional sp + ff algorithm, the trained Q-network reduces the blocking rate by nearly 35 %. [ABSTRACT FROM AUTHOR]