Rational design of solar absorption, heat conversion and water supply for efficient solar steam generation.

Red leaf color is an attractive trait of Malus families, including crabapple (Malus spp.); however, little is known about the molecular mechanisms that regulate the coloration. Dihydroflavonols are intermediates in the production of both colored anthocyanins and colorless flavonols, and this current study focused on the gene expression balance involved in the relative accumulation of these compounds in crabapple leaves. Levels of anthocyanins and the transcript abundances of the anthocyanin biosynthetic gene, dihydroflavonol 4-reductase (McDFR) and the flavonol biosynthetic gene, flavonol synthase (McFLS), were assessed during the leaf development in two crabapple cultivars, ‘Royalty’ and ‘Flame’. The concentrations of anthocyanins and flavonols correlated with leaf color and we propose that the expression of McDFR and McFLS influences their accumulation. Further studies showed that overexpression of McDFR, or silencing of McFLS, increased anthocyanin production, resulting in red-leaf and red fruit peel phenotypes. Conversely, elevated flavonol production and green phenotypes in crabapple leaves and apple peel were observed when McFLS was overexpressed or McDFR was silenced. These results suggest that the relative activities of McDFR and McFLS are important determinants of the red color of crabapple leaves, via the regulation of the metabolic fate of substrates that these enzymes have in common.

Chiral a-functionalized carboxylic acids are valuable precursors for avariety of medicines and natural products. Herein, we described an engineered fatty acid photodecarboxylase (CvFAP)-catalyzed kinetic resolution of a-amino acids and a-hydroxy acids,w hich provides the unreacted R-configured substrates with high yields and excellent stereoselectivity (ee up to 99 %). This efficient light-driven process requires neither NADPH recycling nor prior preparation of esters, which were required in previous biocatalytic approaches.T he structure-guided engineering strategy is based on the scanning of large amino acids at hotspots to narrowthe substrate binding tunnel. To the best of our knowledge,this is the first example of asymmetric catalysis by an engineered CvFAP.

absorption with noticeable photothermal conversion efficiency have been developed for SSG, [7,8] plasmonic metal, [9][10][11][12][13] semiconductors, [14][15][16][17] and carbon-based materials. [18][19][20][21] However, the high-cost and complex manufacturing processes make it hard to prepare on a large-scale. [22] And the accumulation of salt deposits on the photothermal layers results in a sharp decline in SSG performance, thus lacking sustainability and recyclability. [23] Therefore, the SSG are yet far from industrialization that requires low-cost, scalable, and reusable photothermal materials.Carbonization of rampant plants into carbon materials by the high-temperatureinduced pyrolysis provides an alternative solution to these problems, but it still has great challenges. [24] With the development of this technology, a variety of plants have been explored to synthesis different photothermal layers. [25][26][27][28][29] For instance, Xu et al. [28] demonstrated mushrooms as a solar steam generator for the first time. The unique natural structure of mushroom, porous context, and fibrous stipe, make the conversion efficiency of natural and carbonized mushrooms achieve 62% and 78% under 1 sun illumination. Fang et al. [29] found that the unique macroscopic cone shape and hierarchical porous structures of the carbonized lotus seedpods resulted in an evaporation rate and the corresponding evaporation efficiency under 1 sun irradiation of 1.30 kg m −2 h −1 and 86.5%, respectively. The special structure of plant stem is conducive to improving the SSG ability, which is due to the fact that the plant stem can transport water and other nutrients to the upper layer during the whole plant growth process. [30] However, the prices of the current plants, such as mushroom, lotus seedpods, still need to be further cut down (the cost comparison is shown in Table S1 in the Supporting Information). It is of great significance to explore more abundant and low-cost plants for carbonization. Moreover, the mechanical strength and surface of the plants are destroyed by the high temperature during the carbonization process. It is still a big challenge to uniformly and stably deposit the carbonized species on substrates or assemble them to self-stand films at a large scale. [31][32][33] Most importantly, the steam generation rate and evaporation efficiency are yet to be further increased. Solar steam generation (SSG) based on the photothermal effect has beenconsidered to be a promising avenue for freshwater production. However, the fabrication of highly-efficient photothermal layers, at large-scale and low-cost is still a challenge, hindering practical applications. Herein, it is demonstrated that carbonized towel-gourd sponges (CTGS) are excellent photothermal materials. And a capillarity-driven interfacial self-coating method is developed to prepare the super-hydrophilic CTGS/paper photothermal layer. The SSG device based on the CTGS/paper exhibits a high evaporation rate of 1.53 kg m −2 h −1 with an efficiency of 95.9% under 1 sun i...

The thiol−ene click reaction to prepare biobased polyols is a strategy to promote the green and environmental protection of polyurethane. The excessive usage of thiol and low conversion of carbon− carbon double bonds (CC) would severely limit the properties of polyurethane (PU). In this work, a set of eugenol-based polyols were prepared via the thiol−ene click reaction. Interestingly, the conversion of the CC was nearly 100% at the eugenol and various thiol compounds (SH) in a stoichiometric ratio without excess of SH. Then, the prepared polyols were reacted with diphenylmethane-diisocyanate (MDI), followed by a series of structure-adjustable thermosetting polyurethane networks with colorless transparency, high glass transition temperature (T g ), and good mechanical properties being obtained. In particular, the tensile strength was up to 54.88 MPa, and T g can be adjusted from 36.45 to 77.21 °C. Moreover, it is revealed that the compounds with an allyl structure are conducive to the efficient click reaction, and its application in PU can be greatly extended.

Light induces anthocyanin accumulation and hence decides the coloration of apple fruit. It also plays a key role in regulating the biosynthesis of other secondary metabolites. However, the crosstalk between anthocyanin and lignin metabolism during light induction, which affects the edible quality and visual quality of apple fruit, respectively, have rarely been characterized.In this study, we identified and functionally elucidated the roles of miR7125 and its target, cinnamoyl-coenzyme A reductase gene (CCR), in regulating the homeostasis between anthocyanin and lignin biosynthesis during light induction. Overexpressing miR7125 or inhibiting CCR transiently in apple fruit promoted anthocyanin biosynthesis but reduced lignin production under light-induced conditions. Consistently, opposite results were observed under the background of repressed miR7125 or overexpressed CCR.We found that the repressor MdMYB16 and the activator MdMYB1 bound to the miR7125 promoter. Transient repression of MdMYB16 upregulated miR7125 expression significantly, accompanied by decreased levels of MdCCR transcript, resulting in a reduction in the lignin biosynthesis and an increase in anthocyanin accumulation. However, transient overexpression of MdMYB16 produced the opposite effects to MdMYB16-RNAi.The results reveal a novel mechanism by which the MdMYB16/MdMYB1-miR7125-MdCCR module collaboratively regulates homeostasis between anthocyanin and lignin biosynthesis under light induction in apple.

Solar-driven water evaporation is considered to be an effective method for seawater desalination and wastewater purification. Here, we report a novel solar steam generation (SSG) system based on reduced graphene oxide (rGO)/nickel foam. Porous rGO foam acting as a photothermal conversion layer is fabricated by coating the rGO microsheets on the metallic nickel foam. The porous structure shows a rough surface, which can improve the harvest of light by scattering effect. On the other hand, the porous structure ensures the rapid flow of steam in the evaporation process. This SSG system based on rGO/nickel foam converts the absorbed solar energy into heat energy at the water-air interface and can effectively evaporate (∼83.4%) under low irradiation of 1 sun (1 kw m −2 ). The system shows great potential for the practical applications of water treatment at large-scale because of the high efficiency, simple preparation method and low cost.

Cyclohexanone monooxygenases (CHMOs) show very high catalytic specificity for natural Baeyer–Villiger (BV) reactions and promiscuous reduction reactions have not been reported to date. Wild‐type CHMO from Acinetobacter sp. NCIMB 9871 was found to possess an innate, promiscuous ability to reduce an aromatic α‐keto ester, but with poor yield and stereoselectivity. Structure‐guided, site‐directed mutagenesis drastically improved the catalytic carbonyl‐reduction activity (yield up to 99 %) and stereoselectivity (ee up to 99 %), thereby converting this CHMO into a ketoreductase, which can reduce a range of differently substituted aromatic α‐keto esters. The improved, promiscuous reduction activity of the mutant enzyme in comparison to the wild‐type enzyme results from a decrease in the distance between the carbonyl moiety of the substrate and the hydrogen atom on N5 of the reduced flavin adenine dinucleotide (FAD) cofactor, as confirmed using docking and molecular dynamics simulations.