Reconfiguring the Hydrogen Networks of Aqueous Electrolyte to Stabilize Iron Hexacyanoferrate for High-Voltage Decoupled Cell.

Prussian blue analogs (PBAs) as insertion-type cathodes have attracted significant attention in various aqueous batteries to accommodate metal or non-metal ions while suffering from serious dissolution and consequent inferior lifespan. Herein, we reveal that the dissolution of PBAs primarily originates from the locally elevated pH of electrolytes that are caused by proton co-insertion during discharge. To address this issue, a water-locking electrolyte (WLE) has been strategically implemented, which interrupts the generation and Grotthuss diffusion of protons by breaking the well-connected hydrogen bonding network in aqueous electrolytes. As a result, the WLE enables the iron hexacyanoferrate to endure over 1000 cycles at a 1C rate and supports a high-voltage decoupled cell with an average voltage of 1.95 V. These findings provide insights for mitigating dissolution problems in electrode materials, thereby enhancing the viability and performance of aqueous batteries.

Foliar methyl jasmonate (MeJA) application increased 2-acetyl-1-Pyrroline (2-AP) content and modulated antioxidant attributes and yield formation in fragrant rice.

Endogenous methyl jasmonate (MeJA) mediates abiotic and biotic stresses in plants. Exogenous MeJA application can stimulate and defend plant gene expression and induce plant chemical defense. The effects of foliar MeJA application on yield and 2-acetyl-1-pyrroline (2-AP) biosynthesis of fragrant rice are scarcely investigated. The pot experiment was conducted by spraying different concentrations of MeJA (0, 1, and 2 µM; denoted as CK, MeJA-1, and MeJA-2) at the initial heading stage of two fragrant rice cultivars, Meixiangzhan and Yuxiangyouzhan. The results showed that foliar MeJA application significantly increased the grain 2-AP content by 32.1% and 49.7%, respectively, following MeJA-1 and MeJA-2 treatments, and the two cultivars showed the highest 2-AP content upon MeJA-2 treatment. However, the grain yield was increased in MeJA-1 as compared with MeJA-2 treatment for all rice cultivars and no significant differences were observed in yield and yield-related traits compared with CK. The aroma was improved by foliar MeJA application which was strongly associated with the regulation of the precursors and enzymes involved in 2-AP biosynthesis. In particular, the contents of proline, pyrroline-5-carboxylic acid, and pyrroline at maturity, as well as the activities of proline dehydrogenase, ornithine aminotransferase, and pyrroline-5-carboxylic acid synthetase, were positively correlated with grain 2-AP content. On the other hand, foliar MeJA application improved the contents of soluble protein, chlorophyll a and b, and carotenoid, and increased the activity of antioxidant enzymes. Moreover, peroxidase activity and leaf chlorophyll contents were significantly positively correlated to 2-AP content following foliar MeJA application. Therefore, our results implied that foliar MeJA application increased aroma and influenced yield by regulating the physio-biochemistry characters and resistance, and suggested that the optimal concentration of MeJA for the best positive effect on the yield and aroma was 1 µM. However, further study is required to evaluate the metabolic level and molecular basis of the regulatory mechanism of foliar MeJA application on 2-AP in fragrant rice.

Pharmacokinetic Study of Safrole and Methyl Eugenol after Oral Administration of the Essential Oil Extracts of Asarum in Rats by GC-MS.

Asarum is a traditional medicine and has been widely used as remedies for inflammatory diseases, toothache, headache, local anesthesia, and aphthous stomatitis in China, Japan, and Korea. Our previous research found that safrole and methyl eugenol were vital compounds that contribute to distinguish the different species and raw Asarum and its processed products apart. The pharmacokinetics of safrole and methyl eugenol after oral administration of Asarum extract has not been reported yet. In this study, a rapid and simple gas chromatography-mass spectroscopy (GC-MS) method that has a complete run time of only 4.5 min was developed and validated for the simultaneous determination and pharmacokinetic study of safrole and methyl eugenol in rat plasma after administration of Asarum extracts. The chromatographic separation was realized on a DB-17 column (30 m × 0.25 mm × 0.25 µm). And detection was carried out under selected ion monitoring (SIM) mode. Plasma samples were pretreated by n-hexane. The pharmacokinetic parameters provided by this study will be beneficial for further developments and clinical applications of Asarum.

Over-expression of SlJA2 decreased heat tolerance of transgenic tobacco plants via salicylic acid pathway.

KEY MESSAGE: Over-expression of SlJA2 decreased the accumulation of SA, which resulted in significant physiological and gene expression changes in transgenic tobacco plants, leading to the decreased heat tolerance of transgenic tobacco. NAC family, the largest transcription factors in plants, responses to different environmental stimuli. Here, we isolated a typical NAC transcription factor (SlJA2) from tomato and got transgenic tobacco with SlJA2 over-expression. Expression of SlJA2 was induced by heat stress (42 °C), chilling stress (4 °C), drought stress, osmotic stress, abscisic acid, and salicylic acid. Over-expression of SlJA2 decreased the accumulation of salicylic acid by regulating expression of salicylic acid degradation gene under heat stress. Compared to WT plants, stomatal apertures and water loss increased in transgenic plants, and the damage of photosynthetic apparatus and chlorophyll breakdown were more serious in transgenic plants under heat stress. Meanwhile, more H2O2 and O2·- were accumulated transgenic plants and proline synthesis was restricted, which resulted in more serious oxidative damage compared to WT. qRT-PCR analysis showed that over-expression of SlJA2 could down-regulate genes involved in reactive oxygen species scavenging, proline biosynthesis, and response to heat stress. All the above results indicated that SlJA2 may be a negative regulator responded to plant's heat tolerance. Thus, this study provides new insight into roles of NAC family member in plant response to abiotic stress.

Overexpression of tomato SlGGP-LIKE gene improves tobacco tolerance to methyl viologen-mediated oxidative stress.

Ascorbate (AsA) is very important in scavenging reactive oxygen species in plants. AsA can reduce photoinhibition by xanthophyll cycle to dissipate excess excitation energy. GGP is an important enzyme in AsA biosynthesis pathway in higher plants. In this study, we cloned a gene, SlGGP-LIKE, that has the same function but different sequence compared with SlGGP. The function of SlGGP-LIKE gene in response to oxidative stress was investigated using transgenic tobacco plants overexpressed SlGGP-LIKE under methyl viologen treatment. After oxidative stress treatment, transgenic tobacco lines exhibited higher levels of reduced AsA content and APX activity than WT plants. Under oxidative stress, transgenic tobacco plants accumulated less ROS and exhibited lower degrees of REC and MDA. Consequently, relatively higher levels of Pn, Fv/Fm, de-epoxidation status of xanthophyll cycle and D1 protein were maintained in transgenic tobacco plants. Hence, overexpression of SlGGP-LIKE gene enhances AsA biosynthesis and can alleviate the photoinhibition of PSII under oxidative stress.

Overexpression of a novel NAC-type tomato transcription factor, SlNAM1, enhances the chilling stress tolerance of transgenic tobacco.

The NAC proteins are the largest transcription factors in plants. The functions of NACs are various and we focus on their roles in response to abiotic stress here. In our study, a typical NAC gene (SlNAM1) is isolated from tomato and its product is located in the nucleus. It also has a transcriptional activity region situated in C-terminal. The expression levels of SlNAM1 in tomato were induced by 4°C, PEG, NaCl, abscisic acid (ABA) and methyl jasmonate (MeJA) treatments. The function of SlNAM1 in response to chilling stress has been investigated. SlNAM1 overexpression in tobacco exhibited higher germination rates, minor wilting, and higher photosynthetic rates (Pn) under chilling stress. Meanwhile, overexpression of SlNAM1 improved the osmolytes contents and reduced the H2O2 and O2•- contents under low temperature, which contribute to alleviating the oxidative damage of cell membrane after chilling stress. Moreover, the transcripts of NtDREB1, NtP5CS, and NtERD10s were higher in transgenic tobacco, and those increased expressions may confer higher chilling tolerance of transgenic plants. These results indicated that overexpression of SlNAM1 could improve chilling stress tolerance of transgenic tobacco.

Overexpression of tomato GDP-L-galactose phosphorylase gene in tobacco improves tolerance to chilling stress.

KEY MESSAGE: The overexpression of tomato GDP- l -galactose phosphorylase gene enhanced tolerance to chilling stress and reduced photoinhibition of photosystems I and II in transgenic tobacco. Chilling stress is a crucial factor that limits the geographical distribution and yield of chilling-sensitive plants. Ascorbate (AsA) protects plants by scavenging reactive oxygen species and reduces photoinhibition by promoting the conversion of violaxanthin to zeaxanthin in the xanthophyll cycle to dissipate excess excitation energy. Possible mechanisms of AsA for plant photoprotection under chilling stress were investigated by isolating the tomato GDP-L-galactose phosphorylase gene (SlGGP) and producing transgenic tobacco plants with overexpression of SlGGP. The transgenic plants subjected to chilling stress accumulated less H(2)O(2), demonstrated lower levels of ion leakage and malondialdehyde, and acquired higher net photosynthetic rate, higher maximum photochemical efficiency of PSII, and higher D1 protein content compared with the wild-type (WT) plants. The transgenic plants subjected to chilling stress also showed higher GDP-L-galactose phosphorylase activity, increased AsA content as well as ascorbate peroxidase and oxidizable P700 activities than WT plants. Thus, SlGGP overexpression is crucial in promoting AsA synthesis and alleviating photoinhibition of two photosystems.

Overexpression of tomato enhancer of SOS3-1 (LeENH1) in tobacco enhanced salinity tolerance by excluding Na+ from the cytosol.

The salt overly sensitive pathway has an important function in plant salinity tolerance. The enhancer of SOS3-1 (ENH1) participates in a new salinity stress pathway with SOS2 but without SOS3. To investigate the physiological effects and functional mechanism of ENH1 under salt stress, ENH1 was isolated from tomato and overexpressed in tobacco. Under salt stress, the sprouting percentage, fresh weight, and dry weight of transgenic plants were higher than those of wild-type (WT) plants. Under salt stress, the chlorophyll content, net photosynthetic rate, and maximal photochemical efficiency of PSII in transgenic plants decreased more slowly than those in WT plants. The overexpression of LeENH1 in tobacco excluded Na(+) from the cytosol and retained high K(+) levels in the cytosol to reestablish ion homeostasis. Higher thylakoid-bound ascorbate peroxidase activity and lower reactive oxygen species levels were found in transgenic plants under salt stress.