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Summary: Most splicing factors are extensively phosphorylated but their physiological functions in plant salt resistance are still elusive.We found that phosphorylation by SnRK1 kinase is essential for SRRM1L nuclear speckle formation and its splicing factor activity in plant cells. In Arabidopsis, loss‐of‐function of SRRM1L leads to the occurrence of alternative pre‐mRNA splicing events and compromises plant resistance to salt stress.In Arabidopsis srrm1l mutant line, we identified an intron‐retention Nuclear factor Y subunit A 10 (NFYA10) mRNA variant by RNA‐Seq and found phosphorylation‐dependent RNA‐binding of SRRM1L is indispensable for its alternative splicing activity. In the wild‐type Arabidopsis, salt stress can activate SnRK1 to phosphorylate SRRM1L, triggering enrichment of functional NFYA10.1 variant to enhance plant salt resistance. By contrast, the Arabidopsis srrm1l mutant accumulates nonfunctional NFYA10.3 variant, sensitizing plants to salt stress.In summary, this work deciphered the molecular mechanisms and physiological functions of SnRK1‐SRRM1L‐NFYA10 module, shedding light on a regulatory pathway to fine‐tune plant adaptation to abiotic stress at the post‐transcriptional and post‐translational levels. [ABSTRACT FROM AUTHOR]

Biochar modifications are used to improve soil organic carbon (SOC) content, while its effects on soil structure stability and carbon (C) mineralization are less known especially in saline–alkaline soils. A 5 years field experiment was arranged with organic amendments addition in the Yellow River Delta, including (i) NPK, only 255, 56, and 190 kg ha−1 N, P, and K each year, (ii) RS, NPK + rice straw, (iii) BC, NPK + straw‐derived biochar, and (iv) FeBC, NPK + biochar modified with ferric chloride. Relative to NPK treatment, the mean weight diameter was significantly increased with organic amendments addition, which was the highest in FeBC treatment. Meanwhile, SOC content in the soil added with organic amendment was increased by 2%–18%. Compared with the RS and BC, FeBC addition increased the content of stable humin (HU), crystalline Fe oxides (Fed), and amorphous Fe oxides (Feo). There was a positive correlation between HU and Feo/Fed, indicating HU and Fe oxides might form organic mineral complexes to limit SOC biodegradation. While the mineralization rate of SOC in FeBC treatment was decreased by more than 30.4% than that in BC treatment. This might be due to the decrease of soil β‐glucosidase and cellobiohydrolase activities, as well as the abundance of Gammaproteobacteria and Actinobacteria. These results were the mechanism of soil enzyme activity and bacterial community regulating C stability. Therefore, Fe‐modified biochar is a better organic amendment to improve the stability of aggregates structure and SOC in saline–alkaline paddy soil. [ABSTRACT FROM AUTHOR]

SUMMARY: Phytophthora root and stem rot is a worldwide soybean (Glycine max) disease caused by the soil‐borne pathogen Phytophthora sojae. This disease is devastating to soybean production, so improvement of resistance to P. sojae is a major target in soybean breeding. Mitogen‐activated protein kinase (MAPK) cascades are important signaling modules that convert environmental stimuli into cellular responses. Compared with extensive studies in Arabidopsis, the molecular mechanism of MAPK cascades in soybean disease resistance is barely elucidated. In this work, we found that the gene expression of mitogen‐activated protein kinase 6 (GmMPK6) was potently induced by P. sojae infection in the disease‐resistant soybean cultivar 'Suinong 10'. Overexpression of GmMPK6 in soybean resulted in enhanced resistance to P. sojae and silencing of GmMPK6 led to the opposite phenotype. In our attempt to dissect the role of GmMPK6 in soybean resistance to phytophthora disease, we found that MAPK kinase 4 (GmMKK4) and the ERF transcription factor GmERF113 physically interact with GmMPK6, and we determined that GmMKK4 could phosphorylate and activate GmMPK6, which could subsequently phosphorylate GmERF113 upon P. sojae infection, suggesting that P. sojae can stimulate the GmMKK4–GmMPK6–GmERF113 signaling pathway in soybean. Moreover, phosphorylation of GmERF113 by the GmMKK4–GmMPK6 module promoted GmERF113 stability, nuclear localization and transcriptional activity, which significantly enhanced expression of the defense‐related genes GmPR1 and GmPR10‐1 and hence improved disease resistance of the transgenic soybean seedlings. In all, our data reveal that the GmMKK4–GmMPK6–GmERF113 cascade triggers resistance to P. sojae in soybean and shed light on functions of MAPK kinases in plant disease resistance. Significance Statement: The GmMKK4–GmMPK6–GmERF113 cascade enhances resistance to soybean (Glycine max) phytophthora disease by successive phosphorylation events triggered by Phytophthora sojae. Our work provides new perspectives to develop strategies to improve plant disease resistance and insights into the roles of MAPK cascades in resistance against root and stem rot diseases. [ABSTRACT FROM AUTHOR]

Background: Carbon (C) addition to promote phosphorus (P) turnover by microbes is recommended to increase soil P availability. The C‐nutrient stoichiometry of organic materials (OM) are the primary factors in controlling soil P availability and C storage. Methods: A pot experiment was carried out to investigate the effects of different organic matter (OM) with equal carbon input [soybean dregs (SD), chicken manure (CM), and vermicompost (VC), 1000 mg C kg–1 soil] under three P levels (0, 10, and 20 mg P per kg dry soil) on soil P availability, C content, and plant growth in high P fixing soils. Results: Plant biomass and shoot P content were significantly increased in P and OM addition treatment. Application of OM or P alone had no effect on soil available P (AP) but increased the microbial P (MBP). Compared with P addition alone, soil potential AP pool (the sum of soil AP and MBP content) was increased by 89%–200% in both OM and P addition soil. Soil potential AP pool and dissolved organic carbon (DOC) in VC treatment were significantly increased compared with those in CM and SD treatments. On day 60, compared with VC treatment, SD and VC treatments significantly increased alkaline phosphatase (ALP) but decreased soil organic carbon (SOC) content, in which ALP was negatively correlated with SOC and net C balance. Conclusion: A small amount of P and vermicompost addition, which had a balanced carbon‐nutrient stoichiometric ratio, was an effective measurement in improving soil AP pool and C content in P‐fixing soil. [ABSTRACT FROM AUTHOR]

Soil aggregate stability and C stock are key factors in greenhouse vegetable production, which are influenced by the application of different organic materials. However, the responses of soil aggregate stability and C stock to organic amendment in greenhouse vegetable fields are not well understood. A 5‐year study was carried out in greenhouse vegetable fields to investigate the effect of partial substitution of rice husks for manure on soil aggregate stability, C compositions, and their relationships. Four treatments included: (a) no organic fertilization (control), (b) 30 t ha−1 chicken manure (CM), (c) 30 t ha−1 rice husks (RH), and (d) 10 t ha−1 chicken manure plus 20 t ha−1 rice husks (MR). Rice husks addition significantly increased the proportion of >2 mm aggregates and mean weight diameter (MWD), while manure addition showed no difference with control. Polysaccharide and humin (HM) were increased with rice husks addition (RH and MR) compared with that in CM treatment. Polysaccharide and HM caused 86.03% variation of soil aggregate, in which polysaccharide and HM contributed 76.3 and 9.7%, respectively. The soil C stock in CM, RH, and MR treatments was increased by 146, 175, and 164% compared with control, respectively. Aliphatic‐C and amorphous Fe‐oxides (Fe‐ox) content were as higher in MR added soil than those in RH treatment. Partial substitution of rice husk for manure improved soil aggregation stability and thus enhanced C stock by suppling more polysaccharide, HM and liberated soil minerals, which was conducive to the sustainable development in greenhouse vegetable production. [ABSTRACT FROM AUTHOR]

This study aims to improve our understanding of the mechanisms regulating the stability of soil organic carbon (SOC) in saline–alkaline soils. We hypothesized that desorption of SOC is greater in higher salinity/higher pH soils, and the higher level of soil inorganic carbon (SIC) leads to enhanced SOC stability (or weaker SOC desorption) in saline–alkaline soils like those of the Yellow River Delta (YRD). We collected soils from 23 cropland sites (from 0–100 cm) along three lines (upper, middle, and lower lines, with different salinity) across the Yellow River, which have high pH (7.97–9.02). We analyzed SOC, SIC, and water‐extractable organic carbon (WEOC) and salts. Our data showed a large range in SOC (2.3–11.7 kg C m−2) and SIC stocks (13.3–24.7 kg C m−2) over 0–100 cm. The lowest SOC and SIC stocks were found in the lower YRD where soil pH was highest (8.6–9.0). WEOC:SOC ratio (an indicator for SOC desorption) was greater in soils with higher pH, lower SIC, and/or water‐extractable Ca2+ plus Mg2+, indicating that SOC stability is weak in high salinity/high pH soils, but high levels of SIC or Ca2+/Mg2+ can increase SOC stability. Our study suggests that amelioration practice may lead to an increase in both SOC and SIC stocks in saline–alkaline soils. [ABSTRACT FROM AUTHOR]

Summary: Plasma membrane intrinsic proteins (PIPs) are known to be major facilitators of the movement of a number of substrates across cell membranes. From a drought‐resistant cultivar of Oryza sativa (rice), we isolated an OsPIP1;3 gene single‐nucleotide polymorphism (SNP) that is mostly expressed in rice roots and is strongly responsive to drought stress. Immunocytochemistry showed that OsPIP1;3 majorly accumulated on the proximal end of the endodermis and the cell surface around the xylem. Expression of GFP‐OsPIP1;3 alone in Xenopus oocytes or rice protoplasts showed OsPIP1;3 mislocalization in the endoplasmic reticulum (ER)‐like neighborhood, whereas co‐expression of OsPIP2;2 recruited OsPIP1;3 to the plasma membrane and led to a significant enhancement of water permeability in oocytes. Moreover, reconstitution of 10×His‐OsPIP1;3 in liposomes demonstrated water channel activity, as revealed by stopped‐flow light scattering. Intriguingly, by patch‐clamp technique, we detected significant NO3− conductance of OsPIP1;3 in mammalian cells. To investigate the physiological functions of OsPIP1;3, we ectopically expressed the OsPIP1;3 gene in Nicotiana benthamiana (tobacco). The transgenic tobacco plants exhibited higher photosynthesis rates, root hydraulic conductivity (Lpr) and water‐use efficiency, resulting in a greater biomass and a higher resistance to water deficit than the wild‐type did. Further experiments suggested that heterologous expression of OsPIP1;3 in cyanobacterium altered bacterial growth under different conditions of CO2 gas supply. Overall, besides shedding light on the multiple functions played by OsPIP1;3, this work provides insights into the translational value of plant AQPs. Significance Statement: We detected water, CO2 and nitrate transport abilities of rice OsPIP1;3 using different technical approaches. Ectopic expression of the OsPIP1;3 gene in tobacco substantially enhanced plant growth and resistance to water deficit by increasing the photosynthesis rate and root hydraulic conductivity in transgenic plants. This study provides important clues for uncovering the multiple functions played by plant PIP proteins and the related translational value. [ABSTRACT FROM AUTHOR]

Although the function and regulation of SnRK1 have been studied in various plants, its molecular mechanisms in response to abiotic stresses are still elusive. In this work, we identified an AP2/ERF domain‐containing protein (designated GsERF7) interacting with GsSnRK1 from a wild soybean cDNA library. GsERF7 gene expressed dominantly in wild soybean roots and was responsive to ethylene, salt, and alkaline. GsERF7 bound GCC cis‐acting element and could be phosphorylated on S36 by GsSnRK1. GsERF7 phosphorylation facilitated its translocation from cytoplasm to nucleus and enhanced its transactivation activity. When coexpressed in the hairy roots of soybean seedlings, GsSnRK1(wt) and GsERF7(wt) promoted plants to generate higher tolerance to salt and alkaline stresses than their mutated species, suggesting that GsSnRK1 may function as a biochemical and genetic upstream kinase of GsERF7 to regulate plant adaptation to environmental stresses. Furthermore, the altered expression patterns of representative abiotic stress‐responsive and hormone‐synthetic genes were determined in transgenic soybean hairy roots after stress treatments. These results will aid our understanding of molecular mechanism of how SnRK1 kinase plays a cardinal role in regulating plant stress resistances through activating the biological functions of downstream factors. In this work, we reported wild soybean GsSnRK1 bound and phosphorylated GsERF7, which is required for GsERF7 to translocate and transactivate in nucleus. Co‐transformation of these two genes could significantly enhance soybean salt/alkali resistance, suggesting these two proteins interplay to regulate soybean abiotic tolerance. [ABSTRACT FROM AUTHOR]

Phosphate pollution remains a significant hazard to terrestrial and aquatic ecosystems. We developed an economical and efficient method for phosphate adsorption on waste construction concrete modified with seawater. Compared with raw concrete materials, the phosphate adsorption capacity of seawater‐modified waste concrete was highly efficient, especially at low phosphate concentrations. The inflection point for seawater‐modified concrete was 0.66 and 1.22 mg L−1 for the raw material. The relative phosphate adsorption was 4.64 and 2.39 mg g−1, respectively. Phosphate removal was >90% over a pH range of 3 to 11 for the raw and modified materials. Chemical and physical analysis of the modified concrete indicated that Ca and Mg particles were uniformly sequestrated on the surface, and Ca was the determinant controlling phosphate uptake. Phosphate adsorption isotherms fit well using the Freundlich, Temkin, Elovich, Fowler–Guggenheim, and Hill–de Boer models and indicated that intermolecular forces in the concrete particles were enhanced by calcium oxides from seawater. This method can efficiently remove phosphate from polluted water and repurposes waste construction concrete. Core Ideas: Phosphate adsorption capacity of modified waste concrete was highly efficient at low phosphate.Phosphate removal was >90% over a pH range of 3 to 11 for the raw and modified materials.Calcium was the determinant controlling phosphate uptake for seawater‐modified concrete.Intermolecular forces in the concrete particles were enhanced by calcium oxides from seawater. [ABSTRACT FROM AUTHOR]

The plant sucrose nonfermenting kinase 1 (SnRK1) kinases play the central roles in the processes of energy balance, hormone perception, stress resistance, metabolism, growth, and development. However, the functions of these kinases are still elusive. In this study, we used GsSnRK1 of wild soybean as bait to perform library‐scale screens by the means of yeast two‐hybrid to identify its interacting proteins. The putative interactions were verified by yeast retransformation and β‐galactosidase assays, and the selected interactions were further confirmed in planta by bimolecular fluorescence complementation and biochemical Co‐IP assays. Protein phosphorylation analyses were carried out by phos‐tag assay and anti‐phospho‐(Ser/Thr) substrate antibodies. Finally, we obtained 24 GsSnRK1 interactors and several putative substrates that can be categorized into SnRK1 regulatory β subunit, protein modification, biotic and abiotic stress‐related, hormone perception and signalling, gene expression regulation, water and nitrogen transport, metabolism, and unknown proteins. Intriguingly, we first discovered that GsSnRK1 interacted with and phosphorylated the components of soybean nodulation and symbiotic nitrogen fixation. The interactions and potential functions of GsSnRK1 and its associated proteins were extensively discussed and analysed. This work provides plausible clues to elucidate the novel functions of SnRK1 in response to variable environmental, metabolic, and physiological requirements. To reveal the functions of GsSnRK1 kinase of wild soybean, we used it as bait to screen cDNA library of wild soybean by employing yeast two‐hybrid technique. The result showed that GsSnRK1 interacted with 24 proteins that can be classified into several categories with different functions. These data will expand our views to understand the functions of SnRK1 kinases and provide more clues for us to dissect their regulating mechanisms. [ABSTRACT FROM AUTHOR]

Abstract: The phosphorus deficiency is very common in Fe(III)‐rich soil, and one of the key point is to clarify the condition in release or desorption of phosphorus from the Fe(III)‐rich minerals. The present study was to explore the effect of labile carbon on microbial reduction of Fe(III) and release of phosphorus in root‐free sub‐tropical soil. A two‐compartment microcosm was collected, in which the roots of Medicago sativa L. cultivar ‘Aohan' were confined within one compartment by a barrier of 30‐μm nylon mesh, while mycorrhizal hyphae could penetrate to the second compartment. Arbuscular mycorrhizal fungi (Funelliformis mosseae) were added to the root compartment and iron‐reducing bacteria (Klebsiella pneumoniae) were added to the hyphal compartment. Hyphal compartments were provided with two levels of additional carbon (0 and 23 mg C kg−1 soil as sodium acetate) and eight levels of inorganic phosphorus (0 to 35 mg P kg−1 soil as KH2PO4). At low phosphorus levels (< 5 mg P kg−1 soil), shoot biomass, and total biomass phosphorus were substantially less with added carbon in the presence of iron‐reducing bacteria. Carbon had little effect without iron‐reducing bacteria. At higher phosphorus levels (> 15 mg P kg−1 soil), the effect of added carbon was reversed; that is shoot biomass and total biomass phosphorus were greater with added carbon. Available soil phosphorus showed a similar response to added carbon—less at low levels of phosphorus and greater at higher levels of phosphorus. Microbial phosphorus in the presence of iron‐reducing bacteria was always higher with added carbon at all corresponding levels of soil phosphorus. Taken together, these results show that some phosphorus mobilized by iron‐reducing bacteria was converted into microbiological phosphorus, but there was an obligatory requirement for labile carbon for this to happen—reducing the amount of phosphorus that was absorbed by the mycorrhizal hyphae. Iron‐reducing bacteria and mycorrhizae showed a competitive interaction at lower levels of available soil phosphorus, and a complementary, or possibly a carbon‐dependent synergistic function at higher levels of available phosphorus. These results demonstrate that phosphorus released from ferralsols by iron‐reducing bacteria is positively mediated by both phosphorus and labile carbon and, hence, that phosphorus release and mobilization by iron‐reducing bacteria is likely to be enhanced by additions of exogenous carbon. [ABSTRACT FROM AUTHOR]

In a greenhouse experiment, Medicago sativa was grown in iron-rich soil colonized with iron-reducing bacteria (IRB) and/or Glomus mosseae (GM) under different inorganic phosphorus levels, which was to understand the effects of IRB and GM on the activation and turnover of the Fe(III)-fixed phosphorus. The results showed that at the both P rates, dual-inoculation treatment stimulated the hyphal growth and increased the shoot P content. IRB could accelerate mycorrhizal colonization, and showed a positive effect on plant biomass and P uptake at both P levels. Compared to sole-IRB or GM treatment, the dual inoculation treatment increased the soil available P content at both P rates ( p < 0.05), which was in the following order: the dual IRB+GM > the sole IRB > the sole GM > control for soil SMP content at low P rate, whilst the dual IRB+GM > the sole IRB ≈ the sole GM > control treatment at high P rate. Compared with the IRB treatment, the GM treatment significantly decreased the soil available P content and the MBP content at low P rate, but made no difference at high P rates. The soil MBC in dual-inoculation treatment was greatest under the high P level, while the highest soil MBC was the sole-GM treatment under the low P level. The sole GM treatment showed significantly ( p < 0.05) higher soil MBC than that of sole IRB at low P rate ( p < 0.05), while there was no significant differences between sole IRB and sole GM at high P rate. Our results suggested that the interaction between GM and IRB had synergetic effect on the mobilization of Fe(III)-fixed P and their relationship could be regulated by the turnover of MBP. The fact that plants acquired more P via mycorrhizal pathway in the GM-IRB system suggested that the three symbiont of plant-GM-IRB had great ecological and functional significance for P activity in tropical and subtropical soil. [ABSTRACT FROM AUTHOR]

Background information Cyanobacteria possess Aquaporin-Z (AqpZ) membrane channels which have been suggested to mediate the water efflux underlying osmostress-inducible gene expression and to be essential for glucose metabolism under photomixotrophic growth. However, preliminary observations suggest that the biophy-sical properties of transport and physiological meaning of AqpZ in such photosynthetic microorganisms are not yet completely assessed. Results In this study, we used Xenopus laevis oocyte and proteoliposome systems to directly demonstrate the water permeability of the cyanobacterium Synechococcus sp. PCC7942 aquaporin, SsAqpZ. By an in vitro assay of intracellular acidification in yeast cells, SsAqpZ was found to transport also CO2. Consistent with this result, during the entire exponential phase of growth, Synechococcus SsAqpZ-null-mutant cells grew slower than the corresponding wild-type cells. This phenotype was stronger with higher levels of extracellular CO2. In line with the conversion of CO2 gas into HCO3− ions under alkaline conditions, the impairment in growth of the SsAqpZ-null strain was weaker in more alkaline culture medium. Conclusions Cyanobacterial SsAqpZ may exert a pleiotropic function in addition to the already reported roles in macronutrient homeostasis and osmotic-stress response as it appears to constitute an important pathway in CO2 uptake, a fundamental step in photosynthesis. [ABSTRACT FROM AUTHOR]

Plant genomes encode a large number of proteins that potentially function as immune receptors in the defense against pathogen invasion. As a well-characterized receptor kinase consisting of 23 tandem leucine-rich repeats, a transmembrane domain and a serine/threonine kinase, the rice ( Oryza sativa) protein XA21 confers resistance to a broad spectrum of Xanthomonas oryzae pv. oryzae ( Xoo) races that cause bacterial blight disease. We report here that XA21 binding protein 25 ( XB25) belongs to the plant-specific ankyrin-repeat ( PANK) family. XB25 physically interacts, in vitro, with the transmembrane domain of XA21 through its N-terminal binding to transmembrane and positively charged domain ( BTMP) repeats. In addition, XB25 associates with XA21 in planta. The downregulation of Xb25 results in reduced levels of XA21 and compromised XA21-mediated disease resistance at the adult stage. Moreover, the accumulation of XB25 is induced by Xoo infection. Taken together, these results indicate that XB25 is required for maintaining XA21-mediated disease resistance. [ABSTRACT FROM AUTHOR]

The article presents a study which investigated mechanical and compression set properties, swelling property, and stress-strain behavior during compression of polysulfide sealants. The effect of molecular weight and cross-linking agent of liquid polysulfide resin on mechanical and compression set properties of the sealants was noted. The compression performance of the sealants was found to be enhanced when different molecular weight polysulfide resins were used in the sealant simultaneously.

High‐electromagnetic‐shielding cotton fabric (CF) was prepared using carboxyl‐functionalized multiwall carbon nanotubes (MWCNTs‐COOH)/nickel–phosphorus (Ni‐P) electroless plating. Firstly, MWCNTs‐COOH was loaded on CF used to chelate the metal catalyst followed by electroless plating to impart outstanding electrical conductivity and electromagnetic shielding properties. The intermediate MWCNTs‐COOH layer not only improves the bonding strength via the chelating effect, but also can be used as a conductive material. This synergistic action of MWCNTs‐COOH and Ni‐P layer can work together to improve the electromagnetic interference shielding performance. The features of Ni‐P/MWCNTs‐COOH/CF were characterized using scanning electron microscopy, energy‐dispersive spectroscopy, X‐ray photoelectron spectroscopy and X‐ray diffraction. The resulting Ni‐P/MWCNTs‐COOH/CF fabrics show high surface resistance of 1.66 Ω sq−1 and robust electromagnetic shielding effectiveness of 40.2 dB. Furthermore, benefiting from the strong interface interaction, the as‐prepared composite fabrics retain stable performances after undergoing a series of physical and chemical tests, confirming promising practical applications even under harsh conditions. [ABSTRACT FROM AUTHOR]

Background Information: Cyanobacteria possess Aquaporin-Z (AqpZ) membrane channels which have been suggested to mediate the water efflux underlying osmostress-inducible gene expression and to be essential for glucose metabolism under photomixotrophic growth. However, preliminary observations suggest that the biophy-sical properties of transport and physiological meaning of AqpZ in such photosynthetic microorganisms are not yet completely assessed., Results: In this study, we used Xenopus laevis oocyte and proteoliposome systems to directly demonstrate the water permeability of the cyanobacterium Synechococcus sp. PCC7942 aquaporin, SsAqpZ. By an in vitro assay of intracellular acidification in yeast cells, SsAqpZ was found to transport also CO2 . Consistent with this result, during the entire exponential phase of growth, Synechococcus SsAqpZ-null-mutant cells grew slower than the corresponding wild-type cells. This phenotype was stronger with higher levels of extracellular CO2 . In line with the conversion of CO2 gas into HCO3(-) ions under alkaline conditions, the impairment in growth of the SsAqpZ-null strain was weaker in more alkaline culture medium., Conclusions: Cyanobacterial SsAqpZ may exert a pleiotropic function in addition to the already reported roles in macronutrient homeostasis and osmotic-stress response as it appears to constitute an important pathway in CO2 uptake, a fundamental step in photosynthesis., (Copyright © 2013 Soçiété Française des Microscopies and Soçiété de Biologie Cellulaire de France.)