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To improving the understand of the accumulation pattern of soluble sugars in Magnolia wufengensis during natural cold acclimation, the dynamics of freezing tolerance, the content of various soluble sugars in the shoots of M. wufengensis seedlings treated with salicylic acid, and the correlation between them were analyzed from September 2017 to March 2018. Salicylic acid advanced the natural cold acclimation and ultimately enhanced mid-winter hardiness by promoting the accumulation of total soluble sugars. Improved freezing tolerance highly correlated with enhanced glucose, fructose, and raffinose accumulation. The enhanced accumulation of these sugars by elevated amylase, sucrose synthase, and sucrose-P-synthase activities may contribute to advanced natural cold acclimation.

Magnolia wufengensis(Magnoliaceae) is a deciduous landscape species, known for its ornamental value with uniquely shaped and coloured tepals. The species has been introduced to many cities in south China, but low temperatures limit the expansion of this species in cold regions. Bud dormancy is critical for plants to survive in cold environments during the winter. In this study, we performed transcriptomic analysis of leaf buds using RNA sequencing and compared their gene expression during endodormancy, endodormancy release, and ecodormancy. A total of 187,406 unigenes were generated with an average length of 621.82 bp (N50 = 895 bp). In the transcriptomic analysis, differentially expressed genes involved in metabolism and signal transduction of hormones especially abscisic acid (ABA) were substantially annotated during dormancy transition. Our results showed that ABA at a concentration of 100 μM promoted dormancy maintenance in buds ofM. wufengensis. Furthermore, the expression of genes related to ABA biosynthesis, catabolism, and signalling pathway was analysed by qPCR. We found that the expression ofMwCYP707A-1-2was consistent with ABA content and the dormancy transition phase, indicating thatMwCYP707A-1-2played a role in endodormancy release. In addition, the upregulation ofMwCBF1during dormancy release highlighted the enhancement of cold resistance. This study provides new insights into the cold tolerance ofM. wufengensisin the winter from bud dormancy based on RNA-sequencing and offers fundamental data for further research on breeding improvement ofM. wufengensis.

Electrocatalysts play a vital role to overcome the slow kinetics of the oxygen evolution reaction (OER). Herein, we developed iron-doped (Fe-doped) NiCoO 2 nanoplates with NaCl-type structure as an efficient electrocatalyst to speed up OER. NiCoO 2 nanoplates doping with different concentration of Fe were optimized. Specifically, the catalytic properties of 10 mol% Fe-doped NiCoO 2 (denoted as FNC0.1) showed outstanding OER catalytic activity, with an overpotential of 302 mV and a low Tafel slope of 42 mV dec −1 at 10 mA cm −2 in 0.1 M KOH. More importantly, the activity of FNC0.1 was only about 3% loss after 10 h of stability measurements at 1.53 V vs. RHE. The dramatically enhanced OER performance of the FNC0.1 might derive from the synergistic interplay of Co, Ni and Fe, a certain level of amorphization and easily hydroxylation after doping Fe. This work demonstrated that doping Fe would be beneficial to improve the OER activities and the stabilities of the catalysts.

Liquid-phase exfoliation is an effective method to fabricate thin nanosheet materials with layered structure. In this paper, we successfully synthesized NH 4 Co 0.4 Ni 0.6 PO 4 ·H 2 O nanosheets with the thickness of about tens of nanometers through liquid-phase exfoliation under ultrasonication. Specifically, the formamide solution was chosen as the exfoliation solvent due to it is capable of entering the interlayer of bulk materials and rapidly swelling between layers. Electrochemistry tests revealed that the optimized exfoliation time was 4 days. The asymmetric battery type energy storage device AC//NH 4 Co 0.4 Ni 0.6 PO 4 ·H 2 O nanosheets showed an energy density of 10.8 Wh kg −1 at the power density of 703.1 W kg −1 . More importantly, the long-term cycle stability measurements demonstrated that NH 4 Co 0.4 Ni 0.6 PO 4 ·H 2 O nanosheets after exfoliation had an ultra-long cycling life that still retained 102.3% of specific capacitance even 10000 continuous charge/discharge cycles.

Magnolia wufengensis L.Y. Ma et L. R. Wang, a rare species which has been introduced and cultivated from southern China to northern China, frequently suffers from freezing injuries. To figure out the influence of ethephon (ETH) application on the cold tolerance during the natural overwintering of M. wufengensis, one-year shoots subjected to ethephon application at four concentrations (0, 700, 1000, and 1500 mg&middot, L&minus, 1) were collected to measure the physiological and biochemical changes from September 2017 to 1 April 2018. The fall ETH application increased the freezing tolerance of M. wufengensis, and the optimum concentration for M. wufengensis was 1000 mg&middot, 1 (T2), which not only improved the shoot freezing tolerance by 1.4 times, but also led to a 25.0% faster cold acclimation rate and 13.7% slower de-acclimation rate. Moreover, 1000 mg&middot, 1 ETH delayed bud-burst in the spring by 10. 7 d, which was helpful for effectively avoiding cold spells in the spring, and improved the rates of bud survival by 47.1%. The improved freezing tolerance under exogenous ETH application was associated with an increased dehydration and accumulation of proline content. It seems that exogenous ETH application may be used on M. wufengensis grown in northern China to protect against freezing tolerance during the overwintering period.

To investigate the influence of exogenous paclobutrazol (PBZ) application on the natural cold acclimation of Ligustrum lucidum, 1-year-old L. lucidum seedlings were conducted with PBZ at four concentrations (0, 100, 300, and 500 mg L−1) from September to December 2016, and leaves were collected to measure physiological and biochemical parameters. Results showed that 500 mg L−1 was the optimum concentration, which led to stronger freezing tolerance during natural cold acclimation. The enhanced freezing tolerance induced by exogenous PBZ application was attributed to the accumulation of chlorophyll, proline, soluble protein, and soluble sugar, and the regulation of gibberellic acid and abscisic acid. PBZ treatments initiated a cascade of steps for advancing the cold acclimation of L. lucidum. It appears that exogenous PBZ application may be applied to L. lucidum grown in northern China, where the growing periods are short and there are early fall frost events and low mid-winter temperatures.