State Key Laboratory of Systematic and Evolutionary Botany

BACKGROUND: A robust molecular phylogeny is fundamental for developing a stable classification and providing a solid framework to understand patterns of diversification, historical biogeography, and character evolution. As the sixth largest angiosperm family, Lamiaceae, or the mint family, consitutes a major source of aromatic oil, wood, ornamentals, and culinary and medicinal herbs, making it an exceptionally important group ecologically, ethnobotanically, and floristically. The lack of a reliable phylogenetic framework for this family has thus far hindered broad-scale biogeographic studies and our comprehension of diversification. Although significant progress has been made towards clarifying Lamiaceae relationships during the past three decades, the resolution of a phylogenetic backbone at the tribal level has remained one of the greatest challenges due to limited availability of genetic data. RESULTS: We performed phylogenetic analyses of Lamiaceae to infer relationships at the tribal level using 79 protein-coding plastid genes from 175 accessions representing 170 taxa, 79 genera, and all 12 subfamilies. Both maximum likelihood and Bayesian analyses yielded a more robust phylogenetic hypothesis relative to previous studies and supported the monophyly of all 12 subfamilies, and a classification for 22 tribes, three of which are newly recognized in this study. As a consequence, we propose an updated phylogenetically informed tribal classification for Lamiaceae that is supplemented with a detailed summary of taxonomic history, generic and species diversity, morphology, synapomorphies, and distribution for each subfamily and tribe. CONCLUSIONS: Increased taxon sampling conjoined with phylogenetic analyses based on plastome sequences has provided robust support at both deep and shallow nodes and offers new insights into the phylogenetic relationships among tribes and subfamilies of Lamiaceae. This robust phylogenetic backbone of Lamiaceae will serve as a framework for future studies on mint classification, biogeography, character evolution, and diversification.

Long awns are important for seed dispersal in wild rice (Oryza rufipogon), but are absent in cultivated rice (Oryza sativa). The genetic mechanism involved in loss-of-awn in cultivated rice remains unknown. We report here the molecular cloning of a major quantitative trait locus, An-1, which regulates long awn formation in O. rufipogon. An-1 encodes a basic helix-loop-helix protein, which regulates cell division. The nearly-isogenic line (NIL-An-1) carrying a wild allele An-1 in the genetic background of the awnless indica Guangluai4 produces long awns and longer grains, but significantly fewer grains per panicle compared with Guangluai4. Transgenic studies confirmed that An-1 positively regulates awn elongation, but negatively regulates grain number per panicle. Genetic variations in the An-1 locus were found to be associated with awn loss in cultivated rice. Population genetic analysis of wild and cultivated rice showed a significant reduction in nucleotide diversity of the An-1 locus in rice cultivars, suggesting that the An-1 locus was a major target for artificial selection. Thus, we propose that awn loss was favored and strongly selected by humans, as genetic variations at the An-1 locus that cause awn loss would increase grain numbers and subsequently improve grain yield in cultivated rice.

Seed shattering is an important agricultural trait in crop domestication. SH4 (for grain shattering quantitative trait locus on chromosome 4) and qSH1 (for quantitative trait locus of seed shattering on chromosome 1) genes have been identified as required for reduced seed shattering during rice (Oryza sativa) domestication. However, the regulatory pathways of seed shattering in rice remain unknown. Here, we identified a seed shattering abortion1 (shat1) mutant in a wild rice introgression line. The SHAT1 gene, which encodes an APETALA2 transcription factor, is required for seed shattering through specifying abscission zone (AZ) development in rice. Genetic analyses revealed that the expression of SHAT1 in AZ was positively regulated by the trihelix transcription factor SH4. We also identified a frameshift mutant of SH4 that completely eliminated AZs and showed nonshattering. Our results suggest a genetic model in which the persistent and concentrated expression of active SHAT1 and SH4 in the AZ during early spikelet developmental stages is required for conferring AZ identification. qSH1 functioned downstream of SHAT1 and SH4, through maintaining SHAT1 and SH4 expression in AZ, thus promoting AZ differentiation.

A wide range of morphological and physiological traits have changed between cultivated rice Oryza sativa and wild rice Oryza rufipogon under domestication. Here, we report cloning of the An-2 gene, encoding the Lonely Guy Like protein 6 (OsLOGL6), which catalyzes the final step of cytokinin synthesis in O. rufipogon. The near-isogenic line harboring a wild allele of An-2 in the genetic background of the awnless indica Guangluai 4 shows that An-2 promotes awn elongation by enhancing cell division, but decreases grain production by reducing grains per panicle and tillers per plant. We reveal that a genetic variation in the An-2 locus has a large impact on reducing awn length and increasing tiller and grain numbers in domesticated rice. Analysis of gene expression patterns suggests that An-1 regulates the formation of awn primordial, and An-2 promotes awn elongation. Nucleotide diversity of the An-2 locus in cultivated rice was found to be significantly reduced compared with that of wild rice, suggesting that the An-2 locus was subjected to artificial selection. We therefore propose that the selection of genetic variation in An-2 was due to reduced awn length and increased grain yield in cultivated rice.

The occurrence of areas or centers of endemism is commonly attributed to the existence of suitable refugia in which plant lineages survived while others evolved during the late Neogene and Quaternary global cooling. In China, several studies performed since the 1980s have identified the mountains of central and southern China as the main centers of endemism in the country. A recent work studied the patterns of endemism separately for palaeoendemics and neoendemics and found that these tend to be located in different mountain ranges. Whereas, young endemics are preferably located in the mountain ranges of the eastern fringe of the Tibetan Plateau (“plant cradles”), old endemics tend to occur in the mountains of central, south central, and southeastern China (“plant museums”), although there are some exceptions. This pattern seems to be related to the different geological history of the mountain ranges. The eastern fringe of the Tibetan Plateau clearly constitutes the “evolutionary front” of China, probably due to the uninterrupted uplift of the plateau from the late Neogene. In contrast, the relative tectonic stability in central and southern China during most of the Tertiary may have maximized the persistence of relict plant lineages. These results have significant implications in the conservation of the endemic flora, which are briefly discussed.

BACKGROUND: The C4 perennial grass Miscanthus giganteus has proved to be a promising bio-energy crop. However, the biomass recalcitrance is a major challenge in biofuel production. Effective pretreatment is necessary for achieving a high efficiency in converting the crop to fermentable sugars, and subsequently biofuels and other valued products. RESULTS: Miscanthus lutarioriparious was pretreated with a liquid hot water (LHW) reactor. Between the pretreatment severity (PS) of 2.56-4.71, the solid recovery was reduced; cellulose recovery remained nearly unchanged; and the Klason lignin content was slightly increased which was mainly due to the dissolving of hemicellulose and the production of a small amount of pseudo-lignin. The result shows that a LHW PS of 4.71 could completely degrade the hemicellulose in Miscanthus. Hemicellulose removal dislodged the enzymatic barrier of cellulose, and the ethanol conversion of 98.27% was obtained. CONCLUSIONS: Our study demonstrated that LHW served as an effective pretreatment in case that Miscanthus lutarioriparious was used for ethanol production by simultaneous saccharification and fermentation. The combination and the pretreatment method of Miscanthus feedstock holds a great potential for biofuel production.

Sequences of the chloroplast genes matK and rbcL and nuclear ribosomal ITS2 were used for phylogenetic analyses of Berberidaceae. Three major clades were recognized, corresponding to the chromosome base numbers x = 6, 7, and 8/10. Bongardia was sister to the clade containing Achlys and the Podophyllum group, which consists of Diphylleia, Sinopodophyllum, Podophyllum, and Dysosma. The estimated times of divergence of six disjunct genera between Eurasia and North America ranged from 7.5 ± 2.3 Ma to 1.0 ± 0.7 Ma. The intercontinental disjunct lineages of Berberidaceae may have originated in eastern Asia and then migrated to Europe and North America. However, long-distance dispersal may explain the distribution pattern of Achlys. Desert xerophytes of Berberidaceae in southwestern Asia originated in response to the advent of dry climate at different times; Bongardia diverged from its closest relatives at 46.5 ± 3.6 Ma, whereas Leontice differentiated from Gymnospermium at 10.3 ± 3.2 Ma.

Abstract Using ITS and atpB-rbcL spacer sequences of 38 (of 55) species of the highly disjunct Eurasian/North African Epimedium and all three species of its western North American sister genus Vancouveria, we reconstructed the phylogeny of these two genera and dated major splits with a molecular clock approach. Epimedium was found to be monophyletic with a stem age dated to between 9.7 and 7.4 million years ago (My). Within Epimedium, almost all sections as recognized in the most recent classification of the genus were found to be monophyletic but subg. Epimedium was found to be paraphyletic in relation to subg. Rhizophyllum. Range formation in Eurasia proceeded as follows: in a first step, the western Himalayan part of the generic distribution area (sect. Polyphyllon) was separated from the remainder, followed by a split between the Chinese distribution area (sect. Diphyllon) and the remainder, the separation of the highly disjunct range of E. pinnatum from the Caucasus plus E. perralderianum from North Africa (subg. Rhizophyllum) and the remainder, and in a last step the separation of the European E. alpinum plus the Turkish E. pubigerum from the range of the genus in Japan, Korea, northeastern China and Far Eastern Russia (sects. Epimedium and Macroceras). These results imply that the European mountain species are not most closely related to taxa in mountain areas towards the east (e.g., Caucasus, Himalayas) but rather to taxa in the Far East. Accordingly, in Epimedium the link between western Eurasia and eastern Asia apparently was not through intervening mountain regions but probably through a more northerly deciduous forest belt which does not exist any longer. The largest number of species of Epimedium is found in China (sect. Diphyllon: 44 species mainly in Hubei, Sichuan and Guizhou provinces). The age of this clade was dated to 0.52 to 0.4 My. This implies that the diversification of this group probably is the result of frequent range shifts in the Quaternary.

Seed micromorphology of 13 species, belonging to four genera of subfamily Alsinoideae (Caryophyllaceae) were investigated with scanning electron microscopy (SEM), in order to assess their diagnostic significance at generic level and provide additional evidence on species delimitation, as well as correct identification and phylogenetic position. Genera and species of subfamily Alsinoideae exhibit great variation in ultrastructure and a high diversity of novel micromorphological characters were observed. Variation in seed shape, color, hilum, anticlinal wall, epidermal cell, cell surface, margins, and quantitative characters as length and width were studied in detail, compared, illustrated, and their taxonomic significant were discussed. Seed shapes of the species were classified as reniform, round, angular, subcircular, subreniform, and elliptical pyriform, with sub-central, central, basal, and nearly basal hilum. Wavy, irregular, tetragonal, and elongated epidermal cells structure has been observed as an exomorphological character. The present findings show that the micromorphology of subfamily Alsinoideae provides taxonomic information and is helpful to distinguish different species. The results also explained that SEM morphology of seeds provide important data about affinity among taxa and give potential characters in delimitation of members of subfamily Alsinoideae at generic and species level. A principal component analysis allowed to highlight the most outsiders among seed micromorphology with a possible explanation. Taxonomic keys were developed based on micromorphological characters to delimit the species and useful for their quick identification within subfamily Alsinoideae.

Abstract Clematis, a largely temperate genus of vines and lianas, consists of approximately 300 species. Based on a sampling of about 75 species, sequences of the nrITS, the plastid atpB—rbcL spacer, psbA—trnH—trnQ spacer, and rpoB—trnC spacer regions were analyzed using parsimony, maximum likelihood, and Bayesian inference methods. Analyses of the combined data set by the three methods yielded similar topologies. Previously recognized genera including Archiclematis and Naravelia are nested within Clematis, supporting the merging of these genera within Clematis. Ten major clades with various levels of support were detected in the combined analyses. Our results in general do not support previous infrageneric classifications based on morphological characters and suggest significant convergence in floral and vegetative characters in Clematis. Several clades were resolved as regional geographic groups. Bayesian dating suggests a relatively ancient origin of the genus in the Oligocene, yet a relatively recent species radiation of the crown Clematis in the Miocene. Geologic and climatic changes in the late Tertiary to Quaternary are perhaps important for the speciation of Clematis, especially in eastern Asia. Long-distance dispersal of the fruits by wind, water, and/or animals and strong environmental adaptability, are proposed as the main mechanisms for the current cosmopolitan distribution and high species diversity of Clematis.

Abstract The genus Rhododendron (Ericaceae), with more than 1000 species highly diverse in flower color, is providing distinct ornamental values and a model system for flower color studies. Here, we investigated the divergence between two parental species with different flower color widely used for azalea breeding. Gapless genome assembly was generated for the yellow-flowered azalea, Rhododendron molle. Comparative genomics found recent proliferation of long terminal repeat retrotransposons (LTR-RTs), especially Gypsy, has resulted in a 125 Mb (19%) genome size increase in species-specific regions, and a significant amount of dispersed gene duplicates (13 402) and pseudogenes (17 437). Metabolomic assessment revealed that yellow flower coloration is attributed to the dynamic changes of carotenoids/flavonols biosynthesis and chlorophyll degradation. Time-ordered gene co-expression networks (TO-GCNs) and the comparison confirmed the metabolome and uncovered the specific gene regulatory changes underpinning the distinct flower pigmentation. B3 and ERF TFs were found dominating the gene regulation of carotenoids/flavonols characterized pigmentation in R. molle, while WRKY, ERF, WD40, C2H2, and NAC TFs collectively regulated the anthocyanins characterized pigmentation in the red-flowered R simsii. This study employed a multi-omics strategy in disentangling the complex divergence between two important azaleas and provided references for further functional genetics and molecular breeding.

Complete mitochondrial DNA sequences have been used successfully to estimate phylogenetic relationships among animal taxa, and for studies of population genetics and molecular evolution. We made phylogenetic analyses of 22 species of Galliformes, with two species of Anseriformes as outgroups, using maximum likelihood (ML), maximum parsimony (MP) and Bayesian inference (BI) methods based on the nucleotide dataset and the corresponding amino acid dataset of 13 concatenated protein-coding genes. The consensus phylogenetic trees supported monophyly of Galliformes, Phasianidae (nucleotide and amino acid: posterior probabilities 1.00 in BI, bootstrap value > 99% in ML and MP), Coturnicinae, and Gallininae (nucleotide and amino acid: posterior probabilities 1.00 in BI, bootstrap value > 85% in ML and MP), but failed to demonstrate monophyly of Pavoninae and Phasianinae. Our results also support a sister-group relationship between megapodes and all other galliforms. We found that Arborophilinae is basal to the balance of the Phasianidae. Moreover, we suggest that the turkey should be classified in the Phasianinae of Phasianidae. Although the relationships among the various lineages of the Galliformes remain controversial, these results should be useful for further study.

Abstract Cultivated chrysanthemum (Chrysanthemum × morifolium Ramat.) is a beloved ornamental crop due to the diverse capitula types among varieties, but the molecular mechanism of capitulum development remains unclear. Here, we report a 2.60 Gb chromosome-scale reference genome of C. lavandulifolium, a wild Chrysanthemum species found in China, Korea and Japan. The evolutionary analysis of the genome revealed that only recent tandem duplications occurred in the C. lavandulifolium genome after the shared whole genome triplication (WGT) in Asteraceae. Based on the transcriptomic profiling of six important developmental stages of the radiate capitulum in C. lavandulifolium, we found genes in the MADS-box, TCP, NAC and LOB gene families that were involved in disc and ray floret primordia differentiation. Notably, NAM and LOB30 homologs were specifically expressed in the radiate capitulum, suggesting their pivotal roles in the genetic network of disc and ray floret primordia differentiation in chrysanthemum. The present study not only provides a high-quality reference genome of chrysanthemum but also provides insight into the molecular mechanism underlying the diverse capitulum types in chrysanthemum.

Abstract Growing second‐generation energy crops on marginal land is conceptualized as one of the primary means of future bioenergy development. However, the extent to which marginal land can support energy crop production remains unclear. The L oess P lateau of C hina, one of the most seriously eroded regions of the world, is particularly rich in marginal land. On the basis of the previous field experiment of planting M iscanthus species in Q ingyang of the G ansu P rovince, herein, we estimated the yield potential of M iscanthus lutarioriparius , the species with the highest biomass, across the L oess P lateau. On the basis of the radiation model previously developed from M iscanthus field trials, annual precipitation was introduced as an additional variable for yield estimate in the semiarid and semihumid regions of the L oess P lateau. Of 62 million hectares (Mha) of the L oess P lateau, our model estimated that 48.7 Mha can potentially support M iscanthus growth, with the average yield of 17.8 t ha −1 yr −1 . After excluding high‐quality cropland and pasture and land suitable for afforestation, a total of 33.3 Mha of presumably marginal land were left available for producing the energy crop at the average yield of 16.8 t ha −1 yr −1 and the total annual yield of 0.56 billion tons. The analysis of environmental factors indicated that erosion, aridity, and field steepness were the primary contributors to the poor quality of the marginal land. The change of land uses from traditional agriculture to energy crop production may prevent further erosion and land degradation and consequently establish a sustainable economy for the region.

Abstract Reducing terrestrial carbon emissions is a big challenge for human societies. Ecosystem restoration is predominant to reverse land degradation and carbon loss. Though active restoration of croplands is assumed to increase carbon sequestration more than natural regeneration, it still lacks the robust paired comparisons between them. Here we performed a large-scale paired comparison of active versus natural restoration effects on soil carbon sequestration across China. We found that two restoration strategies consistently enhanced soil carbon relative to croplands, however, the benefits of active restoration versus natural regeneration were highly context-dependent. Active restoration only sequestered more carbon in carbon-poor soils but less carbon in carbon-rich soils than natural regeneration. Moreover, active restoration fixed greater carbon in topsoil but less carbon in subsoil. Overall, these findings highlight landscape context-dependent application of active restoration and natural regeneration, further guiding the efficient management of limited resources to maximize the restoration benefits of carbon sequestration.

In this study, we evaluate the impact of fossil assignments and different models of calibration on divergence time estimates carried out as Bayesian analyses. Estimated ages from preceding studies and liverwort inclusions from Baltic amber are used as constraints on a molecular phylogeny of Cephaloziineae (Jungermanniopsida) obtained from sequences of two chloroplast coding regions: rbc L and psb A. In total, the comparison of 12 different analyses demonstrates that an increased reliability of the chronograms is linked to the number of fossils assigned and to the accuracy of their assignments. Inclusion of fossil constraints leads to older ages of most crown groups, but has no influence on lineage through time plots suggesting a nearly constant accumulation of diversity since the origin of Cephaloziineae in the early to Middle Jurassic. Our results provide a note of caution regarding the interpretation of chronograms derived from DNA sequence variation of extant species based on a single calibration point and/or low accuracy of the assignment of fossils to nodes in the phylogeny.

Abstract Rampant homoplasy can be a major challenge in the classification of land plants that have limited morphological differences and/or ecological diversity, such as liverworts and mosses. Here we present the first comprehensive molecular phylogeny of the derived liverwort genus Cololejeunea and its close relatives. We used three markers (trnL—F, rbcL, and nrITS) and 116 accessions representing the geographic range as well as the morphological diversity of this predominantly epiphyllous genus. The molecular data support three major lineages: Colura, Myriocoleopsis, and Cololejeunea. Myriocoleopsis species were resolved in a clade with Cololejeunea minutissima. Aphanolejeunea and Chondriolejeunea were both resolved as putative monophyletic groups, and nested in the Cololejeunea clade. Cololejeunea angustiflora was found to be sister to the clade comprising the remaining Cololejeunea species. Currently accepted subgenera of Cololejeunea were paraphyletic or polyphyletic. Six out of 30 species with multiple accessions were not supported as natural taxa. The current classifications of Cololejeunea have been influenced by frequent homoplasy of morphological characters and do not accurately reflect species relationships. A new classification for this genus is outlined. Our data did not provide evidence for ancient vicariance events where major clades and continents are associated, instead some evidence was recovered for recent intercontinental species range expansion.

Actions and priorities to connect the global community of plant scientists with the world's changing societies are today more imperative than ever. Environmental degradation, unsustainable resource use, and biodiversity loss all require integrated, collaborative solutions. As plant scientists we are increasingly aware and concerned with the accelerating rate of change of our planet and our societies. In our lifetimes we have witnessed major alterations in the structure and make-up of land, water, and the atmosphere, in use of natural resources and agricultural practices, in migration of plants, animals, and people, in rates of urbanization, and in the rise and spread of infectious diseases. The rate of species extinction is greater now than at any time in the last 65 million years. It is clear that this tremendous transformation, with its profound effect on nature, is primarily the result of human activities. The degree of pressure on the environment has never been greater—far beyond the level at which natural systems will be able to maintain sustainable productivity. The need to act is urgent. Equally in transition are our own disciplines in the plant sciences: taxonomy and systematics, morphology and development, evolution and ecology, physiology and genetics. New technologies that generate immense quantities of data are often limited by current infrastructure and information management capabilities; a growing emphasis on laboratory investigations is overshadowing the need for priority field work in rapidly disappearing environments; and balance in training for pure and applied research careers is shifting. In many nations, funding support for basic science is declining along with public trust in science. Parallel to these changes within the plant sciences are those affecting social, political, and economic contexts within which scientific research is conducted. Factors such as growing income inequality among peoples, the uneven redistribution of resources across the globe, and rising levels of conflict within and among nations all impact our ability to conduct meaningful science. At this time of extraordinary challenges, the International Botanical Congress is being held for the first time in China. The increasing wealth of China and the prosperity of its people, coupled with the country's need for and interest in tackling serious national environmental problems, have given the country a key role in combatting climate change. China also has the potential to address biodiversity loss through the development and implementation of a strong national plan in this area. The Chinese linking of “risks” with “opportunities” has never carried more meaning than it does now, at a time when all countries need for their own sake, and for the world, to help achieve global sustainability. The hosting of IBC 2017 in Shenzhen, this Declaration, and the establishment of the Shenzhen International Award in Plant Sciences are measures of China's clear commitment to action. We endorse the following seven priorities for strategic action in the plant sciences. Vigorous development of these areas will allow society, with the help of science, to mitigate impacts of human activities on plant species, habitats, and distributions, and to approach formation of a sustainable world for ourselves and those who follow us. Plant scientists must contribute to regional and global sustainability as directly and efficiently as possible. Key efforts, such as the urgent preservation of plant diversity and the adaptation of agriculture to increasingly warm climates, must be strengthened greatly if we are to meet the challenges ahead. Our research is not conducted in a vacuum, and we cannot continue to act as if we have a great deal of time available, when we simply and clearly do not. We must confront challenges swiftly and directly to mitigate rapidly deteriorating environmental conditions. Plants play a central role in functioning ecosystems. They also are our sole source of food (directly or indirectly), and provide many of our medicines, building materials, clothing materials, and other essential products. Plants deserve a far greater level of scientific attention through enhanced public and private funding than they are receiving at present. Integrated studies are necessary to develop robust solutions to environmental problems. Support across plant sciences, from description to use, should be provided at adequate levels and sustained. Science is by its very nature international, with the plant sciences no exception. Although progress has been made in moving forward with together, stronger international cooperation will be needed to halt biodiversity loss, improve agriculture, and maintain a stable climate. Working together has never been more important. Stable global partnerships are badly needed to overcome barriers and provide integrated, effective solutions to urgent environmental challenges as rapidly as possible. New technical approaches to information and information sharing will only accelerate in the years to come, making sustainability of data platforms imperative. Increasingly large, linked databases reveal new connections and relationships about life on Earth. Our rapidly advancing ability to sequence genomes leads to new ways of understanding the diversity, evolution, and functioning of life on our planet. As these and other new technologies expand, we must apply them in timely, integrated, and practical ways to organize information and address environmental problems. More than half of the land plant species could be extinct in nature by the end of the present century. Although we have given names to many, we know very little about most of them, and there are more that await discovery. Those we know now can be protected or preserved, but the urgency of finding and learning about the unknowns before they become extinct is clear. Doing so will require integration and collaboration on a scale we have not yet achieved. We need to know plants in order to save them, but time is short. Indigenous, traditional, and local knowledge about nature is disappearing even more rapidly than is biodiversity itself. Once lost, such knowledge, with its unique insights into nature, can never be regained. Plant scientists must work together with holders of this knowledge to understand and achieve sustainable environmental stewardship. Cultural diversity, coupled with crop genetic diversity, will be of central importance for future food security. We will need informed collaboration coupled with urgent, rigorous planning and implementation across cultures and knowledge systems. We need to engage the power of the public with the power of nature. People who care about the environment are motivated to do a great deal to protect it and ensure its future. The creation of an ecological civilization, where societies work together in the creation of knowledge and implementation of solutions, cannot remain only an abstract concept. We all need plants, and plants need our care now more than ever—we depend absolutely upon them for our very existence. Embedding that need into the very fabric of our societies will require global engagement, across nations and cultures—this will require all of us. We believe that, by working together, we can unite innovative plant sciences with the needs and strengths of human societies, helping to create new paths to a green, sustainable future for Earth, with plants and people in harmony.

Abstract— We studied leaf cuticles of 48 species of Beilschmiedia, Endiandra, Potameia, Sinopora, and Syndiclis from eastern Asia and Madagascar using light microscopy and scanning electron microscopy. This study shows that leaf cuticles of Lauraceae possess characters useful in taxonomy, including the ornamentation of periclinal walls, straightness and uniformity of thickness of anticlinal walls, stomatal ledges, and surface of the stomatal complex. The stomatal ledges and the surface of the stomatal complex are valuable in supraspecific grouping while ornamentation of periclinal walls, thickness and straightness of anticlinal walls, and presence/absence of round oil deposits are applicable to species identification. Leaf cuticular features together with veinlet anatomy and macromorphology (e.g. terminal buds) were tentatively applied to classify the Asiatic Beilschmiedia group. Five groups are recognized, namely the Beilschmiedia delicata group, the B. glauca group, the B. intermedia group, the Endiandra group, and the Syndiclis group, each of which shares a suit of cuticular characters. Syndiclis (at least the Chinese species) consists of closely related species with a common origin and has not been derived several times independently from Beilschmiedia. Venation type and cuticular characters support a close relationship between Sinopora and Syndiclis. Sinopora hongkongensis is close to Syndiclis pingbienensis.

In core eudicots, euAP3-type MADS-box genes encode a PISTILLATA (PI)-derived motif, as well as a C-terminal euAP3 motif that originated from a paleoAP3 motif of an ancestral APETALA3 (AP3)-like protein through a translational frameshift mutation. To determine the functional and evolutionary relevance of these motifs, a series of point mutation and domain-swap constructs were generated, involving CsAP3, a paleoAP3-type gene from the basal angiosperm Chloranthus spicatus encoding a truncated paleoAP3 motif, and AtAP3, a euAP3-type gene from the core eudicot Arabidopsis thaliana. The chimeric constructs were expressed in A. thaliana under the control of the AP3 promoter or the CaMV 35S promoter in an ap3 mutant or wild-type background, respectively. Significant recovery of AP3 function was obtained in both complementation and ectopic expression experiments whenever the region upstream of the C-terminal motifs (MIK region) from A. thaliana was taken, even when the PI-derived motif and the truncated paleoAP3 motif of CsAP3 substituted for the corresponding sequences from AtAP3. However, no or very weak complementation or gain-of-function was seen when the MIK region was from CsAP3. Our data suggest that changes in the MIK region rather than mutations in the C-terminal domain were of crucial importance for the evolution of the functional specificity of euAP3-type proteins in stamen and petal development.