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Floral MADS-box genes encode transcription factors that play critical roles in the development and evolution of the flower. Proteins of floral MADS-box genes regulate the expression of their downstream genes by forming various homodimers/heterodimers and quaternary complexes. Interactions among proteins of floral MADS-box genes have been documented in several model species, yet the information accumulated so far is still not sufficient to draw a general picture of the evolution of the interactions. We have characterized 28 putative floral MADS-box genes from three representative basal eudicots (i.e., Euptelea pleiospermum, Akebia trifoliata, and Pachysandra terminalis) and investigated the protein-protein interactions (PPIs) among the proteins encoded by these genes using yeast two-hybrid assays. We found that, although the PPIs in basal eudicots are largely consistent with those in core eudicots and monocots, there are lineage-specific features that have not been observed elsewhere. We also reconstructed the evolutionary histories of the PPIs among members of seven MADS-box gene lineages (i.e., AP1, AP3, PI, AG, STK, AGL2, and AGL9) in angiosperms. We revealed that the PPIs were extremely conserved in nine (or 32.1%) of the 28 possible combinations, whereas considerable variations existed in seven (25.0%) of them; in the remaining 12 (or 42.9%) combinations, however, no interaction was observed. Notably, most of the PPIs required for the formation of quaternary complexes, as suggested by the "quartet model," were highly conserved. This suggested that the evolutionarily conservative PPIs may have played critical roles in the establishment of the basic structure (or architecture) of the flower and experienced coevolution to maintain their functions. The evolutionarily variable PPIs, however, seem to have played subsidiary roles in flower development and have contributed to the variation in floral traits.

BackgroundPanax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored.MethodsPolymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIOLOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes.ResultsThe analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003 was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade.ConclusionThe key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

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Efficient treatment of difficult emulsified oil-water wastes is a global challenge. Membranes exhibiting unusual dual superlyophobicity (combined underwater superoleophobicity and underoil superhydrophobicity) are intriguing to realize high-efficiency separation of both oil-in-water and water-in-oil emulsions. For the first time, a robust polymeric membrane demonstrating dual superlyophobicity to common apolar oils was facilely fabricated via a simple one-step phase separation process using an aliphatic polyketone (PK) polymer, thanks to a conjunction of intermediate hydrophilicity and re-entrant fibril-like texture upon the prepared PK membrane. Further chemical modification to improve surface hydrophilicity slightly can enable dual superlyophobicity to both apolar and polar oils. It is found that a nonwetting composite state of oil against water or water against oil was obtainable on the membrane surfaces only when the probe liquids possess an equilibrium contact angle (θ or θ) larger than the critical re-entrant angle of the textured surfaces (73°), which can explain the existences of dual superlyophobicity and also the nonwetting to fully wetting transitions. A simple design chart was developed to map out the operational windows of material hydrophilicity and re-entrant geometry, that is, a possible zone, to help in the rational design of similar interfacial systems from various materials. Switchable filtrations of oil-in-water and water-in-oil nanoemulsions were achieved readily with both high flux and high rejection. The simplicity and scalability of the membrane preparation process and the well-elucidated underlying mechanisms illuminate the great application potential of the PK-based superwetting membranes.

Energy-efficient membrane technology has received tremendous attention for the separation of organic molecules; however, the separation of molecules of less than 100 Da has remained challenging. Herein, a membrane fabricated from interfacial polymerization on a polyketone support was used as an organic solvent reverse osmosis (OSRO) membrane for the separation of organic liquid mixtures. The chemically stable and highly cross-linked selective layer exhibited outstanding separation factors toward large nonpolar molecules from small polar ones with high fluxes. For example, separation factors of 8.4, 11.1, 14.9, and 38.0 were achieved toward toluene, pentane, hexane, and heptane (10 wt % in mixtures), respectively, from methanol solution at 3 MPa, with fluxes around 5 LMH. This membrane outperformed the currently available reverse osmosis membrane and organic solvent nanofiltration membranes in terms of stability and separation factor. This work promotes the development of OSRO separation of organic liquid mixtures without phase change.

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The cost-effective treatment of emulsified oily wastewater discharged by many industries and human societies is a great challenge. Herein, based on an aliphatic polyketone (PK) polymer with a good membrane formation ability and an intrinsic intermediate hydrophilicity, a new class of reduced PK (rPK) membranes combining an all hydrophilic and electrically neutral surface chemistry comprising ketone and hydroxyl groups, and a fibril-like morphology featuring reentrant structure, was facilely prepared by phase separation and following fast surface reduction. The synergetic cooperation of surface chemistry and surface geometry endowed the prepared membranes with excellent superhydrophilicity, underwater superoleophobicity, and underoil superhydrophilicity, in addition to antiprotein-adhesion property. Thus, fouling-resistant and self-cleaning filtrations of challenging oil-in-water emulsions containing adhesive oil, surfactant, high salinity, and proteins were effortlessly realized with high flux (up to ∼50 000 L m −2 h −1 bar −1 ), slow and reversible flux decline, and low oil permeate (<20 ppm). In contrast, a commercial superhydrophilic microporous membrane made of mixed cellulose ester suffered severe fouling gradually or immediately when carrying out the emulsion filtrations due to its less than ideal surface properties. It is believed that this class of membranes with desirable superwettability, high flux, and preparation simplicity can be a potential new benchmark for high performance and large-scale oil−water separation in complex environments.