4-Coumarate:CoA ligase (4CL) is involved in the formation of coenzyme A thioesters of hydroxycinnamic acids that are central substrates for subsequent condensation, reduction, and transfer reactions in the biosynthesis of plant phenylpropanoids. Previous studies of 4CL appear to suggest that many isoenzymes are functionally equivalent in supplying substrates to various subsequent branches of phenylpropanoid biosyntheses. In contrast, divergent members of a 4CL gene family were identified in soybean (Glycine max L.). We isolated three structurally and functionally distinct 4CL cDNAs encoding 4CL1, 4CL2, and 4CL3 and the gene Gm4CL3. A fourth cDNA encoding 4CL4 had high similarity with 4CL3. The recombinant proteins expressed in Escherichia coli possessed highly divergent catalytic efficiency with various hydroxycinnamic acids. Remarkably, one isoenzyme (4CL1) was able to convert sinapate; thus the first cDNA encoding a 4CL that accepts highly substituted cinnamic acids is available for further studies on branches of phenylpropanoid metabolism that probably lead to the precursors of lignin. Surprisingly, the activity levels of the four isoenzymes and steady-state levels of their transcripts were differently affected after elicitor treatment of soybean cell cultures with a b-glucan elicitor of Phytophthora sojae, revealing the down-regulation of 4CL1 vs. up-regulation of 4CL3/4. A similar regulation of the transcript levels of the different 4CL isoforms was observed in soybean seedlings after infection with Phytophthora sojae zoospores. Thus, partitioning of cinnamic acid building units between phenylpropanoid branch pathways in soybean could be regulated at the level of catalytic specificity and the level of expression of the 4CL isoenzymes.

Induced plant resistance traits are expressed in response to attack and occur throughout the plant kingdom. Despite their general occurrence, the evolution of such resistances has rarely been investigated. Here we report that extrafloral nectar, a usually inducible trait, is constitutively secreted by Central American Acacia species that are obligately inhabited by ants. Extrafloral nectar is secreted as an indirect resistance, attracting ants that defend plants against herbivores. Leaf damage induces extrafloral nectar secretion in several plant species; among these are various Acacia species and other Fabaceae investigated here. In contrast, Acacia species obligately inhabited by symbiotic ants nourish these ants by secreting extrafloral nectar constitutively at high rates that are not affected by leaf damage. The phylogeny of the genus Acacia and closely related genera indicate that the inducibility of extrafloral nectar is the plesiomorphic or 'original' state, whereas the constitutive extrafloral nectar flow is derived within Acacia. A constitutive resistance trait has evolved from an inducible one, obviously in response to particular functional demands.

High-impact biological invasions often involve establishment and spread in disturbed, high-resource patches followed by establishment and spread in biotically or abiotically stressful areas. Evolutionary change may be required for the second phase of invasion (establishment and spread in stressful areas) to occur. When species have low genetic diversity and short selection history, within-generation phenotypic plasticity is often cited as the mechanism through which spread across multiple habitat types can occur. We show that trans-generational plasticity (TGP) can result in pre-adapted progeny that exhibit traits associated with increased fitness both in high-resource patches and in stressful conditions. In the invasive sedge, Cyperus esculentus, maternal plants growing in nutrient-poor patches can place disproportional number of propagules into nutrient-rich patches. Using the invasive annual grass, Aegilops triuncialis, we show that maternal response to soil conditions can confer greater stress tolerance in seedlings in the form of greater photosynthetic efficiency. We also show TGP for a phenological shift in a low resource environment that results in greater stress tolerance in progeny. These lines of evidence suggest that the maternal environment can have profound effects on offspring success and that TGP may play a significant role in some plant invasions.

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Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of characters. This makes it difficult to resolve phylogenetic relationships due to convergent evolution of morphological features. Using comparative sequencing of the chloroplast trnK intron, the monophyly of this complex family and hypotheses of infrageneric relationships were tested. Sequences from 71 Nepenthes taxa, representing all groups and two taxa of the closely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were determined and analysed using maximum parsimony methods. Results of this analysis show that the isolated taxa N. distillatoria (Sri Lanka) and N. pervillei (Seychelles) are the most basal, clearly separated from the Madagascan taxa N. madagascariensis and N. masoalensis which are placed in a distinct subclade. This corresponds with some plesiomorphic characters shared by these taxa. N. khasiana (North India) has an intermediate position between these relic Western species and the remaining taxa. The species of the Malay Archipelago can be referred to three distinct lineages which indicate a correlation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a process of migration and a subsequent diversification on the islands of Borneo, Sumatra, Sulawesi and New Guinea. Based on our molecular data, two interpretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the European Focene, or, ii) a Gondwanaland origin at a time when the Indian plate was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Malay Archipelago a new secondary centre of diversity developed. Madagascar, the Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespead common ancestors with subsequent extinction leaving the current taxa. There is no evidence for long‐distance dispersal. Current infragenic classification of Nepenthes is only partly in accordance with the phylogeny inferred from trnK intron data.

Polyploidy has been ubiquitous in plant evolution and is thought to be an important engine of biodiversity that facilitates speciation, adaptation, and range expansion. Polyploid species can exhibit higher ecological tolerance than their progenitor species. For allotetraploid species, this higher tolerance is often attributed to the existence of heterosis resulting from entire genome duplication. However, multiple origins of allopolyploid species may further promote their ecological success by providing genetic variability in ecological traits underlying local adaptation and range expansion. Here we show in a group of allopolyploid species in the genus Aegilops that range size and abundance are correlated with the number of inferred origins. We found that allopolyploid Aegilops spp. contain multiple chloroplast haplotypes, each identical to haplotypes of the diploid progenitor species, indicating multiple origins as the major source of variation. The number of inferred origins in each allopolyploid species was correlated to the total area occupied by the allopolyploid and the tendency for the species to be common. Additionally, we found differences in ecological tolerance among independent origins in Aegilops triuncialis. These results strongly support the hypothesis that the introduction of genetic variability by multiple origins can increase the ecological amplitude and evolutionary success of allopolyploid species.

Despite intensive morphological, chemical and cladistic studies on Caryophyllidae, the circumscription of this subclass and the interfamilial relationships are still under discussion. Using comparative sequencing of the chloroplast matK gene, hypotheses of relationships between the carnivorous Droseraceae, Nepenthaceae and Dioncophyllaceae and ten other families of the Caryophyllidae s.l. were tested and compared with previously published cladograms based on rbcL, 18S rDNA and ORF2280 sequences. Parsimony analyses indicate two well‐differentiated clades. One strongly supported clade comprises the carnivorous families Droseraceae and Nepenthaceae, along with its close relatives Dioncophyllaceae and Ancistrocladaceae. The second clade is restricted to the Polygonaceae, Plumbaginaceae, Tamaricaceae and Frankeniaceae. The Simmondsiaceae are more closely related to Caryophyllales and are at the base of the remaining taxa. Results of this analysis suggest that carnivory within Caryophyllidae s.l. has a monophyletic origin and, with the exception of Triphyophyllum, this syndrome was lost in the taxa of Dioncophyllaceae and Ancistrocladaceae. The exclusion of Drosophyllum from Droseraceae suggests no close relationship with this family. Finally, the data support a sister group relationship between the Plumbaginaceae and Polygonaceae and the Frankeniaceae and Tamaricaceae. An extensive survey of the rpl2 intron via PCR amplification indicates that the intron is absent from chloroplast genomes of Droseraceae and all taxa of Caryophyllales, but is present in Drosophyllum. Consequently, there is evidence for a multiple loss of the intron and strong support that Drosophyllum has affinities outside the Droseraceae. Our sequence data corroborate many aspects of recent cladistic analyses based predominantly on rbcL sequences. This study shows that matK sequences are useful for'phylogenetic inference among closely related members of Caryophyllidae.

Microsatellites play an important role when investigating population and ecological genetics, although high effort in development and genotyping constitute a technical constraint and remains a major bottleneck. Here we use a microsatellite genotyping approach utilizing sequences of amplicons for allele calling (SSR-GBS) based on Illumina that requires less effort and time. The approach consist of development of highly polymorphic loci, sequencing of multiplexed PCR amplified microsatellites on an Illumina Miseq PE 300 platform and bioinformatic treatment of the sequenced data using custom scripts. The procedure allows automation in allele calling, which can be more reliably replicated and thereby removes biases that might prevent concatenation of datasets from different analyses. Additionally, the methodology enhances information content in the sequenced data beyond the traditional amplicon length (AL) approaches. Using 26 newly developed microsatellite markers and SSR-GBS we investigate the population genetic assessment of anthropogenically altered populations of East African Nile tilapia to show the potential of this genotyping approach. More precisely, we compare genotypic data generated considering AL and whole amplicon information (WAI). We found that genotypes based on WAI are not only able to recover a higher number of alleles but also a more detailed genetic structure pattern. We discuss the capability and importance of WAI allele calling and show perspectives for implementation in the future conservation genetic studies. More specifically, we demonstrate how the current markers and techniques might contribute useful information for studies concerning resources sustainable exploitation and conservation using the East African Nile tilapia.