Search

Soybean breeding shows that soybean resources are increasingly narrow due to the depletion of ancestral varieties. We collected salt-tolerant wild soybean samples and seeds from 23 areas affected by heavy salt stress. SEM was used for structural evolution, Plant Print identification, salt and alkali resistance physiology, salt resistance gene and tissue culture experiments. We report here the discovery of Chinese wild soybean salt gland is first reported in the world. The salt tolerance of new soybean varieties is greatly improved by breeding wild soybean with salt gland as the male parent. A batch of new soybean varieties resistant to salt were obtained. The experiment revealed that the diversity of salt tolerance function of wild soybean was closely related to stress tolerance physiology, stress tolerance gene and phylogenetic structure evolution. Our results encourage the use of salt-resistant wild soybeans as paternal breeding to avoid undesirable breeding cycles at the expense of soybean ancestral varieties.

Covalent organic frameworks (COFs) are promising materials for membrane separation thanks to their adjustable topological structures and surface properties of nanopores. Herein, a melamine (Me) doped COF membrane was fabricated by chemically doping the melamine monomer into TpPa COF, which is formed by the condensation reaction between the 1,3,5-triformylphloroglucinol (Tp) and p-phenylenediamine (Pa) monomers via interfacial polymerization . The introduction of melamine monomer allows altering both the pore structure and pore surface of the TpPa COF membrane, leading to enhanced hydrogen purification performance. Specifically, the separation factor of H 2 /CO 2 gas mixture by using the melamine doped TpPa COF (TpPaMe COF) membrane reaches 12.7, with hydrogen permeance of 727 GPU, in sharp contrast to the relatively low separation factor and gas permeance of 7.5 and 618 GPU of the undoped TpPa membrane. Besides, the TpPaMe COF membrane shows good running stability, with H 2 /CO 2 separation performance well surpasses the Robeson 2008 upper bound.

Enzymes play vital roles in biological transformations due to incomparable selectivity. Enzymatic membrane reactors (EMRs) combine enzymes with membranes, and many researchers have studied the synergistic effect of EMRs exerting on enzyme performance. Before the utility of EMRs can expand from natural aqueous media to organic solvents, robust membranes must be developed to promote enzyme protection from hostile forms of media. For this study, laccase was immobilized on an organic-solvent-resistant hydroxylated polyketone (PK-OH) membrane via covalent bonds and served as a model enzyme. Ketone groups facilitated the immobilization via hydrogen bonds, leading to a high immobilization density of 462 µg/cm2. In homogeneous aqueous-organic solvents, the activity of immobilized laccase was up to 3.5 times greater than that of free laccase towards 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). In addition, the results also showed improved activity towards highly concentrated 2,4,6-trichlorophenol and bisphenol A (1.4 g/L). Furthermore, the activity in filtration mode showed a 240% increase over that in batch mode. The immobilized laccase maintained its activity after 40 days of storage, 10 reuse cycles, and 50 h of continuous reaction. These results show that robust polyketone based membrane support will create opportunities for the application of EMRs in aqueous-organic solvents.

The complete chloroplast genome of A. heterotropoides var. mandshuricum reported herein was a circular DNA molecule of 160,262 bp in length. The typical quadripartite structure of the genome consisted of a pair of inverted repeats (IRs) of 27,262 bp separated by a large single-copy (LSC) region of 88,927 bp and a small single-copy region (SSC) of 16,811 bp. The overall GC content of the genome is 38.45%, with 36.7%, 33.1%, and 43.0% in LSC, SSC, IR regions, respectively. The cp genome encoded 125 genes, including 83 protein-coding genes, 34 tRNA genes, and 8 rRNA genes. 138 SSRs were identified in the genome. Phylogenetic anlysis showed the position of A. heterotropoides var. mandshuricum is closely related to A. heterotropoides.

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.

Forward osmosis (FO) is a process that uses the osmotic pressure of a high-concentration draw solution to separate solutes, e.g., ions and molecules, from solvents. We prepared a conjugated microporous polymer (CMP) Janus membrane with very thin hydrophilic and hydrophobic surfaces at both sides, respectively, for FO measurement, in which the asymmetric membrane architecture results in water diode phenomenon, namely, the transport of water in one direction is accelerated while the salt diffusion in the reverse direction is depressed. The asymmetric transport effect of the TTB-CMP Janus membrane on water and salt was thoroughly investigated by using various salt solutions with different hydrated radius as draw solution, e.g., NaCl, KCl, MgCl2, K3[Fe(CN)6], etc. Thanks to the asymmetric transport of water and salts, the Janus membrane shows a high recovered water flux (Jw) of 10.6 L m-2 h-1, with reverse salt flux (Js) as low as 1.39 g m-2 h-1 when 0.1 M NaCl is used as the draw solution. When further used for recovering water from dye solutions, the recovered water flux maintains up to 9.4 L m2 h-1, with molecular-weight cut-off (MWCO) of 680 g mol-1, exhibiting obvious molecular sieving effect originated from the pore size of CMP. This study provides fundamental insight and guidance into the potential application of porous Janus membrane for removing dyes from water.

Organic liquid separation is frequently encountered in chemically relevant industries. Herein, an organic solvent reverse osmosis (OSRO) membrane fabricated by spin coating a Teflon polymer, AF2400, onto a solvent-resistant polyketone support is proposed for organic liquid separation. Nonpolar AF2400 promotes the permeation of nonpolar liquids while inhibiting the transportation of polar liquids, resulting in the efficient separation of polar and nonpolar liquids. A mixture of ethanol and 1-hexane was used as a model, and the effects of feed composition, applied pressure, and filtration time on separation performance were investigated. The optimized membrane demonstrated an impressively high separation factor of 9.5 for 1-hexane over ethanol and an acceptable flux of 1.6 kg m−2 h−1 under 4 MPa (a permeance of 0.04 kg m−2 h−1 bar−1), outperforming the reported membranes in selectivity. The separation performances in alcohol/1-hexane, ethanol/alkane, and ethanol/toluene mixtures were also investigated and the results demonstrated that the molecular size and polarity of the liquids affected the selectivity. The developed membrane contributes to the development of energy-efficient approaches for separating organic liquids.

In this paper we demonstrate the fabrication and properties of a novel poly (N-vinyl imidazole) (PVI) gel composite porous membrane (GCM) used for rapid separation of dyes through permeating adsorption. The GCMs were fabricated by in situ crosslinking of PVI precursor on microporous support membranes with the aid of ammonium persulfate (APS). The characterizations of membrane morphology and surface chemistry showed the PVI gel was introduced not only onto membrane surface but also inside membrane pores. The obtained GCMs could nearly completely remove various anionic dyes from water with a high flux ranging from 40 to 120 L/m2 h under a pressure of 8 cm water column. In an optimized case, the treating capacity of the composite membranes towards sunset yellow (SY) maintains about 79 mg/g with a high flux of 500 L/m2 h under 0.2 bar. The permeation rates reported here is much higher than that of the conventional nanofiltration process for dye separation (about 10 L/m2 h·bar). What's more, GCMs can also be used to deploy the separation of dye mixture effectively. It was found that the protonation of PVI in acidic environment is responsible for the rapid adsorption of anionic dyes by electrostatic attraction. GCMs are easily regenerated by a basic solution and the high separation performance can be kept well over at least five adsorption-regeneration cycles.

A major challenge in enhancing the acceptability of enzymes in enzymatic membrane bioreactors (EMBRs) for industrial processes lies in effectively immobilizing enzymes on supports while maintaining their conformation and activity. This work describes a novel methodology using dicarboxylic acid halides as a spacer for the surface-initiated, covalent immobilization of enzymes onto microporous membranes. One of the reactive carboxyl groups from the dicarboxylic acid halides was immobilized onto the membrane surface and the other was conjugated with an amino group of enzymes via an active ester method. Sebacoyl chloride (SC) and trypsin were used as models of the dicarboxylic acid halide and enzyme, respectively. The effects of the reaction conditions such as reaction temperature, trypsin concentration, reaction time, and SC concentration were investigated on the immobilization efficiency with respect to the surface density, specific activity, and activity retention of the immobilized trypsin. The optimum surface density was 36 mg cm(-2), and the corresponding membrane showed an excellent specific activity of 22 U cm(-2) with a high activity retention of 26% in a soaking mode. Furthermore, in a filtration mode, these values largely improved to 118 U cm(-2) and 145% respectively due to the enhanced diffusion force, meaning that the immobilized trypsin on/in the membrane has higher activity than non-immobilized, native trypsin. In addition, the immobilized trypsin exhibited a remarkable improvement in thermal resistance, continuous operation capability, and reusability. Furthermore, the presented method was also applicable to lipase. This technique provides a practical and simple method to immobilize enzymes and offers a tool to design the membranes used in EMBRs.

The dye wastewater is one of the most difficult industrial wastewaters to treat. It keeps a big challenge to realize fast removal of dyes from water by membrane filtration due to the trade-off between separation selectivity and permeation flux for ultrafiltration or nanofiltration (NF) process. Here we report novel composite porous membranes which can remove anionic dyes from water by ultrafast permeating adsorption. A crosslinked polyethyleneimine (PEI) polymer with strong adsorption ability was incorporated onto a nylon microfiltration membrane by the interfacial amidation reaction between PEI and trimesoyl chloride. The obtained composite membranes were used for the decolorization of dye solution by permeation mode. It was shown that the composite membranes were able to nearly completely remove anionic dyes in acidic conditions with high permeation fluxes. In an optimized case, the adsorption capacity of Sunset Yellow for the composite membranes reached 0.7 mg/cm 2 with a high flux of 85 L/m 2 h under a ultralow pressure of 0.01 bar. This flux was far much higher than that of NF membranes, about 10 L/m 2 h bar. The pH-dependent electrostatic interaction between PEI and anionic dyes was responsible for the rapid dye removal. The adsorption saturated membranes could be effectively regenerated by a simple alkaline washing.

Positively charged composite nanofiltration (NF) membranes with good stability were prepared by dopamine (DA) assisted poly(ethylene imine) (PEI) deposition on a polysulfone ultrafiltration (UF) substrate followed by a cross-linking step. Attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electronic microscopy, and atom force microscopy were employed to characterize the surface chemistry and morphology of the obtained composite membranes. The DA and PEI co-deposition conditions were optimized based on knowledge of the co-deposition mechanism. The effects of the cross-linker concentration, cross-linking time, and reaction temperature on the permeation and separation properties of the prepared composite membranes were investigated in detail. Under optimized conditions, the MgCl2 rejection and permeation flux of the composite membrane reached 80.4% and 19.6 L/(m2·h), respectively (the feed was 0.01 mol/L of MgCl2 solution under a test pressure of 0.4 MPa). The rejection of various salts followed the order MgCl2≈CaCl2>MgSO4>NaCl>Na2SO4, suggesting the membranes were positively charged. The composite membranes showed good durability under alkaline aqueous conditions. This study provided new insights into the fabrication of mussel-inspired thin-film composite nanofiltration membranes.

We sequenced the complete plastid genome of Anomodon attenuatus. The genome size is 125,320 bp with two inverted repeat regions of 9,948 bp separated by a large single-copy region of 86,847 bp and ...

The development of highly selective organic solvent reverse osmosis (OSRO) membrane for organic liquid separation is in great demand, but remains very challenging owing to the small sizes of organic liquids. We recently reported a polyketone (PK) supported polyamide (PA) membrane as an OSRO membrane, but only with a moderate separation factor of 8.4 for methanol from a methanol/toluene mixture. Herein, a well-controlled two-step heat treatment; first oven heating, followed by hot water heating, was described to remarkably improve the selectivity. Heat treatment efficiently shrunk the PA layer and enhanced its hydrophilicity. Consequently, the separation factor was highly improved to 45.0, outperforming previously described membranes. The effects of crucial operation conditions, including co-solute, applied pressure, feed ratio, feed temperature, and operation time were evaluated. The developed highly selective OSRO membrane and systematical separation process investigation make significant contributions in addressing various organic liquid mixture separations.

As fathers become more involved in parenting, more attention has been paid to the association between paternal parenting and adolescent depression. Based on Bronfenbrenner's ecological systems theory and attachment theory, we explored the mediating role of deviant peer affiliation and the moderating role of school climate in the relation between paternal parenting and depression. A total of 1177 Chinese adolescents were assessed with the questionnaires regarding parenting, depression, deviant peer affiliation and school climate. After controlling for maternal parenting, paternal parenting was negatively associated with depression. Deviant peer affiliation mediated the association between paternal parenting and depression. The association between deviant peer affiliation and depression was moderated by school climate, as the effect was stronger among adolescents with positive school climate than those with negative school climate. These findings may help to intervene and reduce adolescent depression.

Here we demonstrate the preparation and properties of an electrolyte-responsive polyethersulfone membrane with an amphiphilic copolymer polyethersulfone- block -poly(sulfobetaine methacrylate) (PES- b -PSBMA) as the blending additive. The PES/PES- b -PSBMA blend membrane was fabricated by traditional non-solvent induced phase separation (NIPS) process. The membrane surface chemistry and hydrophilicity/hydrophobicity of the as-made membranes were analyzed by X-ray photoelectron spectroscopy (XPS) and water contact angle measurement, respectively. The experimental results indicated that the hydrophilicity was remarkably enhanced due to the surface-segregation of hydrophilic PSBMA chains during membrane formation. The water permeability and antifouling ability of the PES/PES- b -PSBMA blend membranes were both greatly improved. In addition, the water permeability and separation characteristics of the blend membranes exhibited a strongly electrolyte-responsive nature, which is attributed to the “anti-polyelectrolyte” effect of the blend membranes in salt solution. Moreover, the electrolyte-responsive characteristic of the blend membranes were reversible and durable. This work provided a valuable strategy to fabricate electrolyte-responsive membranes via the introduction of polyelectrolyte-contained amphiphilic copolymers.

Free-standing symmetrical porous membranes consisting of uniform cylindrical micelles were prepared from a polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymer following a process combining self-assembly and nonsolvent-induced phase separation (SNIPS). The fabricated membranes displayed an impressive ultrastructure by the overlapping of the cylindrical micelles throughout the whole membrane profile (∼65 μm). The effects of copolymer molecular weight and membrane-formation condition on membrane morphology were investigated and discussed in detail. It was concluded that the cylindrical micellar membranes could be obtained in a wide window of fabrication conditions as low molecular weight of PS-b-P4VP was used as the raw material. The permeation tests indicated that the water permeability of the symmetrical membranes reached 400 L/(h m2 bar) in neutral condition, which was comparable to that of the block copolymer (BCP) isoporous membrane reported in the literature. Significantly, the permea...

Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase 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. Results: The 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. Conclusion: The 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.

Membrane filtration has proven its advantages in removing micropollutants from water. However, concentrated micropollutants in feed solutions still pose a high risk to environments and may contaminate the permeate. Here, a proof-of-concept of enzyme-aided forward osmosis (E-FO) process was demonstrated. In E-FO process, degradation and rejection of micropollutants occurred simultaneously, providing a detoxified feed solution and a cleaner permeate. A lab-made polyketone-based thin film composite membrane with high flux and high micropollutants rejection was explored as FO membrane. Laccase and 2, 4, 6-trichlorophenol (TCP) was employed as a model enzyme and micropollutant, respectively. Compared with a single enzyme catalysis, E-FO process showed a higher degradation efficiency owing to enzyme condensation during filtration. Compared with a single FO process including 0.051 mM TCP in feed solution, E-FO process adding 0.8 μM laccase showed 7.4 and 10.7 times lower TCP permeation and membrane adsorption when operated for 10 h. An enzyme-aided reverse osmosis (E-RO) process can produce clean water with similar quality as that of E-FO, however, suffers from membrane fouling. This work provides an insight in facile coupling of efficient enzyme catalysis with low fouling FO process for high quality water production from contaminated water resources.

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 re-entrant 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

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 (θow or θwo) 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.

Brønsted acidic ionic liquids (BAILs) are unique ionic liquids that display chemical structures similar to zwitterions, and they were typically used as solvents and catalysts. In this work, an imidazole-based BAIL monolayer was fabricated onto poly(ether sulfone) (PES) membranes via surface clicking reactions, and the multifunctionality, including ion exchange and biofouling resistance to proteins and bacteria, was demonstrated, which was believed to be one of few works in which BAIL had been considered to be a novel fouling resistance layer for porous membranes. The successful immobilization of the BAILs onto a membrane surface was confirmed by X-ray photoelectron spectroscopy analysis, contact angle measurement, and ζ potential determination. The results from Raman spectroscopy showed that, as a decisive step prior to zwitterion, the BAIL was deprotonated in aqueous solution, and biofouling resistance to proteins and bacteria was found. However, BAIL displayed ion exchange ability at lower pH, and surface hydrophilicity/hydrophobicity of membranes could be tuned on purpose. Our results have demonstrated that the BAIL grafted onto membranes will not only act as an antibiofouling barrier like zwitterions but also provide a platform for surface chemical tailoring by ion exchange, the property of which will become especially important in acidic solutions where the fouling resistance performances of zwitterions are greatly weakened.

Here we describe the development of versatile antifouling polyethersulfone (PES) filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive. Amphiphilic polyethersulfone-block-poly(2-hydroxyethyl methacrylate) (PES-b-PHEMA) was beforehand designed and used as the blending additive of PES membranes prepared by phase inversion technique. The surface enriched PHEMA blocks on membrane surface acted as an anchor to immobilize the initiating site. Poly(sulfobetaine methacrylate) (PSBMA) were subsequently grafted onto the PES blend membranes by surface-initiated atom transfer radical polymerization (SI-ATRP). The analysis of surface chemistry confirmed the successful grafting of zwitterionic PSBMA brushes on PES membrane surface. The resulted PES-g-PSBMA membranes were capable of separating proteins from protein solution and oil from oil/water emulsion efficiently. Furthermore, the modified membranes showed high hydrophilicity and strongly antifouling properties due to the incorporation of well-defined PSBMA layer. In addition, the PES-g-PSBMA membranes exhibited excellent blood compatibility and durability during the washing process. The developed antifouling PES membranes are versatile and can find their applications in protein filtration, blood purification and oil/water separation, etc.

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.

Members of the AP1/SQUA subfamily of plant MADS-box genes play broad roles in the regulation of reproductive meristems, the specification of sepal and petal identities, and the development of leaves and fruits. It has been shown that AP1/SQUA-like genes are angiosperm-specific, and have experienced several major duplication events. However, the evolutionary history of this subfamily is still uncertain. Here, we report the isolation of 14 new AP1/SQUA-like genes from seven early-diverging eudicots and the identification of 11 previously uncharacterized ESTs and genomic sequences from public databases. Sequence comparisons of these and other published sequences reveal a conserved C-terminal region, the FUL motif, in addition to the known euAP1/paleoAP1 motif, in AP1/SQUA-like proteins. Phylogenetic analyses further suggest that there are three major lineages (euAP1, euFUL, and AGL79) in core eudicots, likely resulting from two close duplication events that predated the divergence of core eudicots. Among the three lineages, euFUL is structurally very similar to FUL-like genes from early-diverging eudicots and basal angiosperms, whereas euAP1 might have originally been generated through a 1-bp deletion in the exon 8 of an ancestral euFUL- or FUL-like gene. Because euFUL- and FUL-like genes usually have broad expression patterns, we speculate that AP1/SQUA-like genes initially had broad functions. Based on these observations, the evolutionary fates of duplicate genes and the contributions of the frameshift mutation and alternative splicing to functional diversity are discussed.