Expression of floral MADS-box genes in Sinofranchetia chinensis (Lardizabalaceae): implications for the nature of the nectar leaves

Background and Aims

The perianths of the Lardizabalaceae are diverse. The second-whorl floral organs of Sinofranchetia chinensis (Lardizabalaceae) are nectar leaves. The aim of this study was to explore the nature of this type of floral organ, and to determine its relationship to nectar leaves in other Ranunculales species, and to other floral organs in Sinofranchetia chinensis.

Methods

Approaches of evolutionary developmental biology were used, including 3′ RACE (rapid amplification of cDNA ends) for isolating floral MADS-box genes, phylogenetic analysis for reconstructing gene evolutionary history, in situ hybridization and tissue-specific RT-PCR for identifying gene expression patterns and SEM (scanning electron microscopy) for observing the epidermal cell morphology of floral organs.

Key Results

Fourteen new floral MADS-box genes were isolated from Sinofranchetia chinensis and from two other species of Lardizabalaceae, Holboellia grandiflora and Decaisnea insignis. The phylogenetic analysis of AP3-like genes in Ranunculales showed that three AP3 paralogues from Sinofranchetia chinensis belong to the AP3-I, -II and -III lineages. In situ hybridization results showed that SIchAP3-3 is significantly expressed only in nectar leaves at the late stages of floral development, and SIchAG, a C-class MADS-box gene, is expressed not only in stamens and carpels, but also in nectar leaves. SEM observation revealed that the adaxial surface of nectar leaves is covered with conical epidermal cells, a hallmark of petaloidy.

Conclusions

The gene expression data imply that the nectar leaves in S. chinensis might share a similar genetic regulatory code with other nectar leaves in Ranunculales species. Based on gene expression and morphological evidence, it is considered that the nectar leaves in S. chinensis could be referred to as petals. Furthermore, the study supports the hypothesis that the nectar leaves in some Ranunculales species might be derived from stamens.     

Esterified, optical pure (3S, 3′S)-astaxanthin from flowers of Adonis annua

The quantitative carotenoid composition of the red flower petals of Adonis annua is reported. Optically pure (3S, 3′S)-astaxanthin occurs both as a diester (64% of total carotenoid) and as a monoester (11%). The optical purity was determined by hydrolysis of the natural esters in the absence of oxygen and subsequent HPLC analysis of the paren -ketol esterified with (−)-camphanic acid. All non-animal sources hitherto examined synthesize pure 3S,3′S- or 3R,3′R-isomers of astaxanthin, whereas marine animal sources contain mixtures of all three optical isomers, including the meso form.     

Synthèse et hydrolyse du saccharose dans l'œillet alimenté avec une solution glucosée

Sucrose synthesis and sucrose hydrolysis in cut carnations (Dianthus caryophyllus) supplied with glucose solution .
Sucrose synthesis and hydrolysis in cut carnations supplied with a glucose solution have been investigated using both entire floral branches and floral branches without any of their organs (petals, non-petaloid pieces, leaves) and isolated organs. – The flower is a more active sink that the leaves. The transformationn of glucose into sucrose is essential for the ability of the flower to use the exogenous glucose. All organs of the floral branch (petals, ovaries and sepals, leaves, stem) are able to form sucrose. The hydrolysis of the obtained sucrose occurs nearly exclusively in the petals.     

Microemulsion Assisted Assembly of 3D Porous S/Graphene@g‐C3N4 Hybrid Sponge as Free‐Standing Cathodes for High Energy Density Li–S Batteries

A 3D porous sulfur/graphene@g‐C₃N₄ (S/GCN) hybrid sponge, which can be directly applied as a free‐standing cathode for Li–S batteries, is realized via a microemulsion assisted assembly approach. In this strategy, the interior oil emulsion droplets serve as soft templates to form pores to accommodate sulfur and the hydrophilic GCN stacks around oil droplets to assemble into a crosslinked 3D network. Through this microemulsion encapsulation route, S/GCN cathodes with a sulfur loading as high as 82 wt% can be achieved. Furthermore, the enriched N‐sites in GCN macropores offer numerous adhesion sites for polysulfides, realizing a “physical‐chemical” dual‐confinement for polysulfides from diffusion. Moreover, the robust and highly porous 3D graphene frameworks render efficient electron/Li⁺ transport pathways for fast kinetics as well as good structure integrity. Consequently, in comparison to the conventional G‐sponge/Li₂S_n catholyte system, S/GCN delivers a higher specific capacity, superior high‐rate capability (612 mA h g^?1 at 10 C), and alleviated anode corrosion issues. Particularly, an energy density as high as 1493 W h kg^?1 (calculated on the total weight of the cathode) and an extremely low capacity fading rate of 0.017% per cycle over 800 cycles at 0.3 C are achieved.     

凤丹牡丹花朵不同发育时期挥发性成分积累规律与蒸馏工艺研究

以凤丹牡丹(Paeonia ostii)花瓣为试材,采用三因素三水平正交试验设计,结合气相色谱-质谱联用(GC-MS)技术,探讨其花发育时期[大风铃期(S1)、圆桃期(S2)和破绽期(S3)]、料液比 (1:1、1:2和1:3)和蒸馏时间(1 h、2 h和3 h)对蒸馏提取牡丹花露的工艺及其挥发性成分积累规律的影响。结果表明,不同发育时期和不同蒸馏工艺获得的牡丹花露中挥发性成分含量和种类有明显差别,9种处理获得的花露中共检测到145种挥发性成分,包括醇类、萜烯类、醛类、酯类、烷烃及其他物质,其中S1期最多为96种,占比最大的是其他物质;S2和S3期占比最大的是烷烃类。从蒸馏工艺来看,同一发育时期花瓣采用不同料液比和蒸馏时间提取,其挥发性成分种类及含量有差异,S1、S2和S3期花瓣选择料液比分别为1:1、1:3和1:2,蒸馏1 h为最佳蒸馏工艺。     

Capsella as a model system to study the evolutionary relevance of floral homeotic mutants

Several lines of evidence suggest that homeotic changes played a considerable role during the evolution of flowers. This, however, is difficult to reconcile with the predominant evolutionary theory which rejects any drastic, saltational change of the phenotype as reasonable mode of evolution due to its assumed negative impact on the fitness of the affected organism. A better understanding of the evolutionary potential of homeotic transitions requires a study of the performance of respective mutant varieties in the wild. Here we introduce ``Stamenoid petals' (Spe), a variety of Capsella bursa-pastoris (shepherd's purse), as a suitable model to study the evolutionary potential of floral homeotic mutants. In the flowers of the Spe variety all petals are transformed into stamens, while all other floral organs are unaffected. In contrast to most other homeotic mutants the Spe variety occurs on several locations in relatively large and stable populations in the wild. Due to its close relationship to the model plant Arabidopsis thaliana, the Spe variety of C. bursa-pastoris can be rigorously studied, from the molecular genetic basis of the phenotype to its consequences on the fitness in wild habitats. Investigations on Spe may thus help to clarify whether homeotic transformations have the potential to contribute to macroevolution.     

The Space Confinement Approach Using Hollow Graphitic Spheres to Unveil Activity and Stability of Pt‐Co Nanocatalysts for PEMFC

The performance of polymer electrolyte fuel cells is strongly correlated to the electrocatalytic activity and stability. In particular, the latter is the result of an interplay between different degradation mechanisms. The essential high stability, demanded for real applications, requires the synthesis of advanced electrocatalysts that withstand the harsh operation conditions. In the first part of this study, the synthesis of oxygen reduction electrocatalysts consisting of Pt‐Co (i.e., Pt₅Co, Pt₃Co, and PtCo) alloyed nanoparticles encapsulated in the mesoporous shell of hollow graphitic spheres (HGS) is reported. The mass activities of the activated catalysts depend on the initial alloy composition and an activity increase on the order of two to threefold, compared to pure Pt@HGS, is achieved. The key point of the second part is the investigation of the degradation of PtCo@HGS (showing the highest activity). Thanks to pore confinement, the impact of dissolution/dealloying and carbon corrosion can be studied without the interplay of other degradation mechanisms that would induce a substantial change in the particle size distribution. Therefore, impact of the upper potential limit and the scan rates on the dealloying and electrochemical surface area evolution can be examined in detail.     

墨兰花朵发育和衰老生理的初步研究

目的：了解墨兰花朵的发育和衰老生理,为控制黑兰花期提供科学依据。方法：测定不同发育期的墨兰花瓣的干重／鲜重、呼吸速率、过氧化物酶活性及可溶性糖含量。结果：黑兰花朵在由花蕾发育到衰老的过程中,上述指标呈现出一定的变化规律。