Biomimetic Design of 3D Fe3O4/V-EVOH Fiber-Based Self-Floating Composite Aerogel to Enhance Solar Steam Generation Performance.

An interfacial solar steam generation evaporator for seawater desalination has attracted extensive interest in recent years. Nevertheless, challenges still remain in relatively low evaporation rate, unsatisfactory energy conversion efficiency, and salt accumulation. Herein, we have demonstrated a biomimetic bilayer composite aerogel consisting of bottom hydrophilic and vertically aligned EVOH channels and an upper hydrophobic conical Fe3O4 array. Thanks to the design merits, the 3D Fe3O4/V-EVOH evaporator exhibits a high evaporation rate of ∼2.446 kg m-2 h-1 and an impressive solar energy conversion efficiency of ∼165.5% under 1 sun illumination, which is superior to those of state-of-the-art evaporators reported so far. Moreover, the asymmetrical wettability not only allows the evaporator to self-float on the water but also facilitates the salt ion diffusion in the channels; thus, the evaporator shows no salt crystals on its surface and only a 6% decrease in evaporation performance even after the salt concentration increases from 0 to 10.0 wt %.

Hydrogen-Bond-Repairing Solar Evaporator with Reconstructed Large-Width Channels for Durable Solarizing Seawater.

Conventional solarizing seawater suffers from inefficiency and space constraints. Interfacial solar vapor generation (ISVG) presents an energy-efficient alternative, yet the scalability, adaptability, and durability of a solar evaporator for practical use are remaining concerns. Herein, a hydrogen-bond-repairing solar evaporator featuring reconstructed large-width channels is proposed for ongoing solarization of seawater in ISVG. The polyacrylamide/trehalose/graphene hydrogel (PTGH) exhibits excellent mechanical properties and large-width salt discharge channels. PTGH achieves a notable water evaporation rate of 2.82 kg m-2 h-1 under 1 sun and remains effective even in low-temperature environments. The large-area PTGH is able to continuously operate for solarizing seawater under different conditions, until raw brine is highly concentrated, and eventually solid salt is separated from water. Compared to conventional solarizing seawater, PTGH can save 66.67%-75% of time or land to obtain the same amount of solid salt.

Heat-Localized and Salt-Resistant 3D Hierarchical Porous Ceramic Platform for Efficient Solar-Driven Interfacial Evaporation.

Solar-driven interfacial evaporation (SDIE) is a highly promising approach to achieve sustainable desalination and tackle the global freshwater crisis. Despite advancements in this field, achieving balanced thermal localization and salt resistance remains a challenge. Herein, the study presents a 3D hierarchical porous ceramic platform for SDIE applications. The utilized alumina foam ceramics (AFCs) exhibit remarkable corrosion resistance and chemical stability, ensuring a prolonged operational lifespan in seawater or brines. The millimeter-scale air-filled pores in AFCs prevent thermal losses through conduction with bulk water, resulting in heat-localized interfaces. The hydrophilic nature of macroporous AFC skeletons facilitates rapid water replenishment on the evaporating surface for effective salt-resistant desalination. Benefiting from its self-radiation adsorption and side-assisted evaporation capabilities, the AFC-based evaporators exhibit high indoor evaporation rates of 2.99 and 3.54 kg m-2 h-1 under one-sided and three-sided illumination under 1.0 sun, respectively. The AFC-based evaporator maintains a high evaporation rate of ≈2.77 kg m-2 h-1 throughout the 21-day long-term test. Furthermore, it achieves a daily water productivity of ≈10.44 kg m-2 in outdoor operations. This work demonstrates the potential of 3D hierarchical porous ceramics in addressing the trade-off between heat localization and salt resistance, and contributes to the development of durable solar steam generators.

Achieving "Ion Diode" Salt Resistance in Solar Interfacial Evaporation by a Tesla Valve-Like Water Transport Structure.

Salt deposition is a disturbing problem that limits the development of passive solar-driven interfacial evaporation. Inspired by the passive fluid control mechanism of the Tesla valve, a novel solar evaporator is proposed with a Tesla valve-like water transport structure to prevent salt accumulation at the evaporation interface. A unique "ion diode" salt resistance of this evaporator is significantly achieved by optimizing the two asymmetric water transport structures, consisting of one Tesla valve-like side and one wide-leg side, which establish a reverse-suppressing and forward-accelerating water transport channel. In contrast to the limited ion migration of the typical symmetric solar evaporator, such a channel caused by the water/salt ions transport difference between two water supply structures, reinforces the water/salt ions supply on the wide-leg side, thus leading to an apparent unidirectional salt ions migration from the wide-leg side to bulk water through the Tesla valve-like side. Consequently, an evaporation rate of 3.25 kg m-2 h-1 and a conversion efficiency of 83.27% under 2 suns are achieved in 16 wt% NaCl solution. The development of the Tesla Valve-like evaporator provides a new perspective for solving salt deposition and realizing scalable applications of solar-driven interfacial evaporation.

Global analysis of key post-transcriptional regulation in early leaf development of Limonium bicolor identifies a long non-coding RNA that promotes salt gland development and salt resistance.

Limonium bicolor, known horticulturally as sea lavender, is a typical recretohalophyte with salt glands in its leaf epidermis that secrete excess Na+ out of the plant. Although many genes have been proposed to contribute to salt gland initiation and development, a detailed analysis of alternative splicing, alternative polyadenylation patterns, and long non-coding RNAs (lncRNAs) has been lacking. Here, we applied single-molecule long-read mRNA isoform sequencing (Iso-seq) to explore the complexity of the L. bicolor transcriptome in leaves during salt gland initiation (stage A) and salt gland differentiation (stage B) based on the reference genome. We identified alternative splicing events and the use of alternative poly(A) sites unique to stage A or stage B, leading to the hypothesis that they might contribute to the differentiation of salt glands. Based on the Iso-seq data and RNA in situ hybridization of candidate genes, we selected the lncRNA Btranscript_153392 for gene editing and virus-induced gene silencing to dissect its function. In the absence of this transcript, we observed fewer salt glands on the leaf epidermis, leading to diminished salt secretion and salt tolerance. Our data provide transcriptome resources for unraveling the mechanisms behind salt gland development and furthering crop transformation efforts towards enhanced survivability in saline soils.

Pantoea jilinensis D25 enhances tomato salt tolerance via altering antioxidant responses and soil microbial community structure.

As a major challenge to global food security, soil salinity is an important abiotic stress factor that seriously affects the crop growth and yield. In this study, the mechanism of salt resistance of Pantoea jilinensis D25 and its improving effect on salt tolerance of tomato were explored with salt resistance-related genes identified in strain D25 by genomic sequencing. The results showed that in comparison with the treatment of NaCl, strain D25 significantly increased the fresh weight, shoot length, root length, and chlorophyll content of tomato under salt stress by 46.7%, 20%, 42.4%, and 44.2%, respectively, with increased absorptions of various macronutrients and micronutrients and decreased accumulation of Na+. The activities of defense enzymes (peroxidase, catalase, superoxide dismutase, phenylalanine ammonia-lyase, and polyphenol oxidase) were enhanced, while the content of malondialdehyde was decreased. The results of quantitative real-time PCR analysis showed that the expressions of genes (SlSOS1, SlNHX1, SlHKT1.1, SlSOD1, SlAPX2, SlAOS, SlPin II, Solyc08g066270.1, Solyc03g083420.2 and SlGA20ox1) related to ion transporters, antioxidant machinery, key defense, serine/threonine protein kinase synthesis, and gibberellin (GA) signal protein were up-regulated and were the highest in the treatment of both NaCl and strain D25. The activities of enzymes (dehydrogenase, urease, invertase, and catalase activities) related to soil fertility were enhanced. The results of 16S rRNA sequencing showed that soil microbial diversity and the abundance of probiotics (e.g., Acidibacter, Limnobacter, and Romboutsia) were significantly increased. Our study provided strong experimental evidence to support the agricultural application of strain D25 in the promotion of growth in crops.

Preparation and Performance Evaluation of Self-Cementing Nanoscale Polymeric Microspheres with Salt and Temperature Tolerance.

Polymer microspheres with temperature and salt resistance were synthesized using the anti-suspension polymerization method, incorporating the functional monomers AMPS, AM, and AA. To enhance their self-gelling properties, the microspheres were designed with a core-shell structure. The shell is composed of a polymeric surfactant, fatty alcohol polyoxyethylene ether methacrylate (AEOMA), which serves as a thermosensitive crosslinking agent, enabling self-crosslinking upon shell decomposition, addressing compatibility with reservoir pore throat dimensions. Comprehensive characterizations including infrared spectroscopy, scanning electron microscopy, optical microscopy, and laser particle size analysis were conducted. The microspheres exhibited successful synthesis, a nanoscale size, and regular spherical morphology. They demonstrated excellent temperature and salt resistance, making them suitable for high-temperature, high-salinity reservoir profile control. With a stable three-dimensional network structure, the microspheres displayed good expansion behavior due to hydrophilic groups along the polymer chains, resulting in favorable water affinity. Even after aging, the microspheres maintained their gelling state with a distinct and stable microscopic network skeleton. They exhibited superior plugging performance in low-permeability reservoirs, while effectively improving water absorption profiles in reservoirs with permeability contrasts of 10 to 80, thereby enhancing oil recovery.

CsbD, a Novel Group B Streptococcal Stress Response Factor That Contributes to Bacterial Resistance against Environmental Bile Salts.

Group B Streptococcus (GBS) can cause many serious infections and result in severe symptoms depending on the infected organs. To survive and initiate infection from the gastrointestinal tract, GBS must resist physiochemical factors, such as bile salts, a potent antibacterial compound in the intestine. We found that GBS isolated from diverse sources all possess the capability to defend bile salts and permit survival. By constructing the GBS A909 transposon mutant library (A909Tn), we identified several candidate genes that might participate in the bile salt resistance of GBS. The rodA and csbD genes were validated as relevant to bile salt resistance. The rodA gene was anticipated to be related to peptidoglycan synthesis and influence the bile salt resistance of GBS by cell wall construction. Notably, we found that the csbD gene worked as a bile salt resistance response factor and influenced several ABC transporter genes, specifically at the later growth period of GBS under bile salt stress. We further detected the marked intracellular bile salt accumulation in ΔcsbD by hydrophilic interaction chromatography-liquid chromatography/mass spectrometry (HILIC-LC/MS). Collectively, we showed a novel GBS stress response factor, csbD, contributes to bacterial survival in bile salts by sensing bile salt stress and subsequently induces transcription of transporter genes to excrete bile salts. IMPORTANCE GBS, a conditional pathogenetic colonizer of the human intestinal flora, can cause severe infectious diseases in immunocompromised patients. Therefore, it is critical to understand the factors that contribute to the resistance to bile salts, which are abundant in the intestine but harmful to bacteria. We identified rodA and csbD genes involved in bile salt resistance using a transposon insertion site sequencing (TIS-seq) based screen. The rodA gene products might be involved in peptidoglycan synthesis as important contributors to stress resistance including bile salts. However, the csbD gene conferred bile salt resistance by promoting transporter genes transcription at the later growth period of GBS in response to bile salts. These findings developed a better understanding of the stress response factor csbD on the bile salt resistance of GBS.

TabZIP60 is involved in the regulation of ABA synthesis-mediated salt tolerance through interacting with TaCDPK30 in wheat (Triticum aestivum L.).

MAIN CONCLUSION: TabZIP60 is found to interact with TaCDPK30 and act as a positive regulator of ABA synthesis-mediated salt tolerance in wheat. Wheat basic leucine zipper (bZIP) transcription factor (TabZIP60) was previously found to act as a positive regulator of salt resistance. However, its molecular mechanism in response to salt stress in wheat is still unclear. In this study, TabZIP60 was found to interact with wheat calcium-dependent protein kinase (TaCDPK30), which belonged to group III of CDPK family, and was induced by salt, polyethylene glycol, and abscisic acid (ABA) treatments. This mutation of serine 110 in TabZIP60 resulted in no interaction with TaCDPK30. Moreover, TaCDPK30 was involved in interactions with wheat protein phosphatase 2C clade A (TaPP2CA116/TaPP2CA121). TabZIP60-overexpressing wheat plants showed increased salt tolerance, as exhibited by better growth status, higher soluble sugar, and lower malonaldehyde contents of transgenic plants than wild-type wheat cv. Kenong 199 under salt stress. Moreover, transgenic lines showed high ABA content by upregulating ABA synthesis-related gene expression levels. TabZIP60 protein could bind and interact with the promoter of the wheat nine-cis epoxycarotenoid dioxygenase (TaNCED2) gene. Furthermore, TabZIP60 upregulated several stress response gene expression levels, which could also increase the plant's ability to resist salt stress. Thus, these results suggest that TabZIP60 could function as a regulator of ABA synthesis-mediated salt tolerance through interacting with TaCDPK30 in wheat.

Transcriptome profiling reveals multiple regulatory pathways of Tamarix chinensis in response to salt stress.

KEY MESSAGE: Multiple regulatory pathways of T. chinensis to salt stress were identified through transcriptome data analysis. Tamarix chinensis (Tamarix chinensis Lour.) is a typical halophyte capable of completing its life cycle in soils with medium to high salinity. However, the mechanisms underlying its resistance to high salt stress are still largely unclear. In this study, transcriptome profiling analyses in different organs of T. chinensis plants in response to salt stress were carried out. A total number of 2280, 689, and 489 differentially expressed genes (DEGs) were, respectively, identified in roots, stems, and leaves, with more DEGs detected in roots than in stems and leaves. Gene Ontology (GO) term analysis revealed that they were significantly enriched in "biological processes" and "molecular functions". Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that "Beta-alanine metabolism" was the most differentially enriched pathway in roots, stems, and leaves. In pair-to-pair comparison of the most differentially enriched pathways, a total of 14 pathways, including 5 pathways in roots and leaves, 6 pathways in roots and stems, and 3 pathways in leaves and stems, were identified. Furthermore, genes encoding transcription factor, such as bHLH, bZIP, HD-Zip, MYB, NAC, WRKY, and genes associated with oxidative stress, starch and sucrose metabolism, and ion homeostasis, were differentially expressed with distinct organ specificity in roots, stems, and leaves. Our findings in this research provide a novel approach for exploring the salt tolerance mechanism of halophytes and identifying new gene targets for the genetic breeding of new plant cultivars with improved resistance to salt stress.