Browsing by Subject "PLANTS"

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  • Vesterinen, Eero J.; Kaunisto, Kari M.; Lilley, Thomas M. (2020)
    We report a detection of a surprising similarity in the diet of predators across distant phyla. Though just a first glimpse into the subject, our discovery contradicts traditional aspects of biology, as the earliest notions in ecology have linked the most severe competition of resources with evolutionary relatedness. We argue that our finding deserves more research, and propose a plan to reveal more information on the current biodiversity loss around the world. While doing so, we expand the recently proposed conservation roadmaps into a parallel study of global interaction networks.
  • Mgbeahuruike, Eunice Ego; Holm, Yvonne; Vuorela, Heikki; Amandikwa, Chinyere; Fyhrquist, Pia (2019)
    Ethnobotanical relevance: Piper guineense occurs commonly in West Africa where it is used for fungal infections instead of the costly and not always accessible conventional antifungals. Fungal, yeast-based diseases are common in West-Africa especially among those living with HIV/AIDS, and thus this study was performed in Imo state, South-Eastern Nigeria, where P. guineense is predominantly used for the treatment of fungal diseases, such as skin rashes, oral thrush and vaginosis. Aim of study: The scarce number of previous studies on the documentation of the traditional uses of P. guineense extracts for the treatment of fungal infections in Nigeria prompted this survey. The investigation focused on how traditional healers recognize and diagnose fungal infections, how P. guineense is collected, on the various parts used for the treatments, methods of preparations, administrations and treatments. In addition, an in vitro anti fungal screening of P. guineense fruit and leaf extracts of various polarities, and piperine and piperlongumine, representing the main constituents in these extracts, were performed. Methods: A house to house ethnobotanical survey was conducted using questionnaires. Twenty traditional medical practitioners (TMP) and herb sellers from ten villages were interviewed. Four human pathogenic strains of yeast and Cryptococcus neoformans, a yeast-like basidiomycete causing meningitis in immunocompromised individuals, were used for the antifungal screening. Results: The traditional medical practitioners (TMP) and herb sellers explained that the leaves and fruits are the most commonly used plant parts for the treatments. The oral intake of the extracts in locally produced bamboo alcohol (Kai-kai) is the most common method of administration. In accordance with these recorded traditional uses, we found that extracts of P. guineense were growth inhibitory against the fungal strains with MIC values ranging from 39 to 2500 g/mL. The lowest MIC value of 39 g/mL was recorded for a methanol fruit extract against Candida albicans, C. glabrata and C. tropicalis. In addition, ethanol and hexane fruit extracts were effective against the growth of C. albicans and C. glabrata, respectively, with a MIC of 78 g/mL. Piperlongumine and piperine were active against C. albicans with MIC values of 39 and 78 g/mL respectively. Conclusion: P. guineense fruit and leaf extracts, as well as their piperamide alkaloid constituents piperine and piperlongumine, have interesting antifungal properties and could have potential as new antifungal scaffolds. Our results warrant further in-depth investigations to isolate and characterize piperamide alkaloids and other compounds responsible for the antifungal activity in the extracts.
  • Liu, Miao; Liu, Xingxing; Kang, Jieyu; Korpelainen, Helena; Li, Chunyang (2020)
    This study clarifies the mechanisms of Cd uptake, translocation and detoxification in Populus cathayana Rehder females and males, and reveals a novel strategy for dioecious plants to cope with Cd contamination. Females exhibited a high degree of Cd uptake and root-to-shoot translocation, while males showed extensive Cd accumulation in roots, elevated antioxidative capacity, and effective cellular and bark Cd sequestration. Our study also found that Cd is largely located in epidermal and cortical tissues of male roots and leaves, while in females, more Cd was present in vascular tissues of roots and leaves, as well as in leaf mesophyll. In addition, the distributions of sulphur (S) and phosphorus (P) were very similar as that of Cd in males, but the associations were weak in females. Scanning electron microscopy and energy spectroscopy analyses suggested that the amounts of tissue Cd were positively correlated with P and S amounts in males, but not in females (a weak correlation between S and Cd). Transcriptional data suggested that Cd stress promoted the upregulation of genes related to Cd uptake and translocation in females, and that of genes related to cell wall biosynthesis, metal tolerance and secondary metabolism in males. Our results indicated that coordinated physiological, microstructural and transcriptional responses to Cd stress endowed superior Cd tolerance in males compared with females, and provided new insights into mechanisms underlying sexually differential responses to Cd stress.
  • Arteaga, Alba; Malumbres-Olarte, Jagoba; Gabriel, Rosalina; Ros-Prieto, Alejandra; Casimiro, Pedro; Sanchez, Ana Fuentes; Albergaria, Isabel S.; Borges, Paulo A. V. (2020)
    The aim of our study was to characterise and compare the richness and composition of endemic, native (non-endemic) and introduced arthropod assemblages of two Azorean Historic Gardens with contrasting plant species composition. We hypothesised that Faial Botanic Garden would hold higher arthropod diversity and abundance of native and endemic arthropod species due to its larger native plant community. Species were collected using several arthropod standardised techniques between April 2017 and June 2018. We used the alpha diversity metrics (Hill series) and the partitioning of total beta diversity (beta(total)) into its replacement (beta(repl)) and richness (beta(rich)) components, to analyse the adult and total arthropod community. The orders Araneae, Coleoptera and Hemiptera were also studied separately. Our results show that the number of exotic arthropod species exceeds the number of native and/or the endemic species in both gardens, but the arthropod community of Faial Botanic Garden exhibited a higher density of endemic and native species. Despite some minor exceptions, the geographic origins of plant communities largely influenced the arthropod species sampled in each garden. This study improves our knowledge about urban arthropod diversity in the Azores and shows how well-designed urban garden management and planning contribute to the conservation of native and endemic Azorean species.
  • Tanhuanpää, Pirjo; Erkkilä, Maria; Kalendar, Ruslan; Schulman, Alan Howard; Manninen, Outi (2016)
    Timothy (Phleum pratense L.), a cool-season hexaploid perennial, is the most important forage grass species in Nordic countries. Earlier analyses of genetic diversity in a collection of 96 genebank accessions of timothy with SSR markers demonstrated high levels of diversity but could not resolve population structure. Therefore, we examined a subset of 51 accessions with REMAP markers, which are based on retrotransposons, and compared the diversity results with those obtained with SSR markers.
  • Puhlmann, Marie-Luise; de Vos, Willem M. (2020)
    Fibers are increasingly recognized as an indispensable part of our diet and vital for maintaining health. Notably, complex mixtures of fibers have been found to improve metabolic health. Following an analysis of the fiber content of plant-based products, we found the taproot of the chicory plant (Cichorium intybus L) to be 1 of the vegetables with the highest fiber content, comprising nearly 90% of its dry weight. Chicory roots consist of a mixture of inulin, pectin, and (hemi-)cellulose and also contain complex phytochemicals, such as sesquiterpene lactones that have been characterized in detail. Nowaday, chicory roots are mainly applied as a source for the extraction of inulin, which is used as prebiotic fiber and food ingredient. Chicory roots, however, have long been consumed as a vegetable by humans. The whole root has been used for thousands of years for nutritional, medicinal, and other purposes, and it is still used in traditional dishes in various parts of the world. Here, we summarize the composition of chicory roots to explain their historic success in the human diet. We revisit the intake of chicory roots by humans and describe the different types of use along with their various methods of preparation. Hereby, we focus on the whole root in its complex, natural form, as well as in relation to its constituents, and discuss aspects regarding legal regulation and the safety of chicory root extracts for human consumption. Finally, we provide an overview of the current and future applications of chicory roots and their contribution to a fiber-rich diet.
  • Greiser, Caroline; Hylander, Kristoffer; Meineri, Eric; Luoto, Miska; Ehrlen, Johan (2020)
    The role of climate in determining range margins is often studied using species distribution models (SDMs), which are easily applied but have well-known limitations, e.g. due to their correlative nature and colonization and extinction time lags. Transplant experiments can give more direct information on environmental effects, but often cover small spatial and temporal scales. We simultaneously applied a SDM using high-resolution spatial predictors and an integral projection (demographic) model based on a transplant experiment at 58 sites to examine the effects of microclimate, light and soil conditions on the distribution and performance of a forest herb, Lathyrus vernus, at its cold range margin in central Sweden. In the SDM, occurrences were strongly associated with warmer climates. In contrast, only weak effects of climate were detected in the transplant experiment, whereas effects of soil conditions and light dominated. The higher contribution of climate in the SDM is likely a result from its correlation with soil quality, forest type and potentially historic land use, which were unaccounted for in the model. Predicted habitat suitability and population growth rate, yielded by the two approaches, were not correlated across the transplant sites. We argue that the ranking of site habitat suitability is probably more reliable in the transplant experiment than in the SDM because predictors in the former better describe understory conditions, but that ranking might vary among years, e.g. due to differences in climate. Our results suggest that L. vernus is limited by soil and light rather than directly by climate at its northern range edge, where conifers dominate forests and create suboptimal conditions of soil and canopy-penetrating light. A general implication of our study is that to better understand how climate change influences range dynamics, we should not only strive to improve existing approaches but also to use multiple approaches in concert.
  • Daly, Paul; Peng, Mao; Mitchell, Hugh D.; Kim, Young-Mo; Ansong, Charles; Brewer, Heather; de Gijsel, Peter; Lipton, Mary S.; Markillie, Lye Meng; Nicora, Carrie D.; Orr, Galya; Wiebenga, Ad; Hilden, Kristiina S.; Kabel, Mirjam A.; Baker, Scott E.; Makela, Miia R.; de Vries, Ronald P. (2020)
    Saprobic fungi, such as Aspergillus niger, grow as colonies consisting of a network of branching and fusing hyphae that are often considered to be relatively uniform entities in which nutrients can freely move through the hyphae. In nature, different parts of a colony are often exposed to different nutrients. We have investigated, using a multi-omics approach, adaptation of A. niger colonies to spatially separated and compositionally different plant biomass substrates. This demonstrated a high level of intra-colony differentiation, which closely matched the locally available substrate. The part of the colony exposed to pectin-rich sugar beet pulp and to xylan-rich wheat bran showed high pectinolytic and high xylanolytic transcript and protein levels respectively. This study therefore exemplifies the high ability of fungal colonies to differentiate and adapt to local conditions, ensuring efficient use of the available nutrients, rather than maintaining a uniform physiology throughout the colony.
  • Zliobaite, Indre; Fortelius, Mikael (2018)
    How food intake and mastication scale to satisfy the metabolic needs of mammals has been the subject of considerable scientific debate. Existing theory suggests that the negative allometric scaling of metabolic rate with body mass is compensated by a matching allometric scaling of the chewing rate. Why empirical studies have found that the scaling coefficients of the chewing rate seem to be systematically smaller than expected from theory remains unknown. Here we explain this imparity by decoupling the functional surface area of teeth from overall surface area. The functional surface area is relatively reduced in forms emphasizing linear edges (e.g., lophodont) compared with forms lacking linear structures (e.g., bunodont). In forms with reduced relative functional surface, the deficit in food processed per chew appears to be compensated for by increased chewing rate, such that the metabolic requirements are met. This compensation accounts for the apparent difference between theoretically predicted and observed scaling of chewing rates. We suggest that this reflects adaptive functional evolution to plant foods with different fracture properties and extend the theory to incorporate differences in functional morphology. (C) 2017 Elsevier Ltd. All rights reserved.
  • Safronov, Omid; Kreuzwieser, Juergen; Haberer, Georg; Alyousif, Mohamed S.; Schulze, Waltraud; Al-Harbi, Naif; Arab, Leila; Ache, Peter; Stempfl, Thomas; Kruse, Joerg; Mayer, Klaus X.; Hedrich, Rainer; Rennenberg, Heinz; Salojarvi, Jarkko; Kangasjarvi, Jaakko (2017)
    Plants adapt to the environment by either long-term genome evolution or by acclimatization processes where the cellular processes and metabolism of the plant are adjusted within the existing potential in the genome. Here we studied the adaptation strategies in date palm, Phoenix dactylifera, under mild heat, drought and combined heat and drought by transcriptomic and metabolomic profiling. In transcriptomics data, combined heat and drought resembled heat response, whereas in metabolomics data it was more similar to drought. In both conditions, soluble carbohydrates, such as fucose, and glucose derivatives, were increased, suggesting a switch to carbohydrate metabolism and cell wall biogenesis. This result is consistent with the evidence from transcriptomics and cis-motif analysis. In addition, transcriptomics data showed transcriptional activation of genes related to reactive oxygen species in all three conditions (drought, heat, and combined heat and drought), suggesting increased activity of enzymatic antioxidant systems in cytosol, chloroplast and peroxisome. Finally, the genes that were differentially expressed in heat and combined heat and drought stresses were significantly enriched for circadian and diurnal rhythm motifs, suggesting new stress avoidance strategies.
  • Ayvaz, Muavviz; Guven, Avni; Fagerstedt, Kurt Valter (2015)
    Potato crop production in Turkey ranks on the thirteenth place in the world. Toxicity is a problematic issue for some parts of the Turkish soils. Hence, it is very important to clarify the physiological responses of plants to toxic mineral stress. In this study, two different potato cultivars - Solanum tuberosum cv. Resy and Solanum tuberosum cv. Agria - were used as a study material. Excess boron was applied in two different concentrations (5 mmol/L and 12.5 mmol/L) 32 days after planting the tubers. Plants were harvested at the end of 15 days of excess boron application. Chlorophyll fluorescence (Fv/Fm) was measured. Shoot height and shoot-root fresh weight contents were determined. Analyses were carried out for the contents of the endogenous hormones indole-3-acetic acid (IAA) and abscisic acid (ABA) by using gas chromatography-mass spectrophotometry (GS-MS). According to the obtained data, plants' shoot height did not change, whereas the shoot's fresh weight decreased significantly with increasing of the boron concentrations in cv Resy, by applying 12.5 mmol/L boron. With 12.5 mmol/L boron, the photosynthesis was negatively affected in both cultivars. Boron application led to increased endogenous IAA and ABA content in both cultivars. As a result, cv. Resy showed more resistance to excess boron. Findings on the hormone metabolism and chlorophyll fluorescence in different cultivars will shed a light on understanding the physiological response to excess mineral stress.
  • Vesala, Timo; Sevanto, Sanna; Grönholm, Tiia; Salmon, Yann; Nikinmaa, Eero; Hari, Pertti; Hölttä, Teemu (2017)
    The pull of water from the soil to the leaves causes water in the transpiration stream to be under negative pressure decreasing the water potential below zero. The osmotic concentration also contributes to the decrease in leaf water potential but withmuch lesser extent. Thus, the surface tension force is approximately balanced by a force induced by negative water potential resulting in concavely curved water-air interfaces in leaves. The lowered water potential causes a reduction in the equilibrium water vapor pressure in internal (sub-stomatal/ intercellular) cavities in relation to that over water with the potential of zero, i.e., over the flat surface. The curved surface causes a reduction also in the equilibrium vapor pressure of dissolved CO2, thus enhancing its physical solubility to water. Although the water vapor reduction is acknowledged by plant physiologists its consequences for water vapor exchange at low water potential values have received very little attention. Consequences of the enhanced CO2 solubility to a leaf water-carbon budget have not been considered at all before this study. We use theoretical calculations and modeling to show how the reduction in the vapor pressures affects transpiration and carbon assimilation rates. Our results indicate that the reduction in vapor pressures of water and CO2 could enhance plant water use efficiency up to about 10% at a leaf water potential of -2 MPa, and much more when water potential decreases further. The low water potential allows for a direct stomatal water vapor uptake from the ambient air even at sub-100% relative humidity values. This alone could explain the observed rates of foliar water uptake by e.g., the coastal redwood in the fog belt region of coastal California provided the stomata are sufficiently open. The omission of the reduction in the water vapor pressure causes a bias in the estimates of the stomatal conductance and leaf internal CO2 concentration based on leaf gas exchange measurements. Manufactures of leaf gas exchange measurement systems should incorporate leaf water potentials in measurement set-ups.
  • Peivastegan, Bahram; Hadizadeh, Iman; Nykyri, Johanna; Nielsen, Kare Lehmann; Somervuo, Panu; Sipari, Nina; Tran, Cuong; Pirhonen, Minna (2019)
    BackgroundStored potato (Solanum tuberosum L.) tubers are sensitive to wet conditions that can cause rotting in long-term storage. To study the effect of water on the tuber surface during storage, microarray analysis, RNA-Seq profiling, qRT-PCR and phytohormone measurements were performed to study gene expression and hormone content in wet tubers incubated at two temperatures: 4 degrees C and 15 degrees C. The growth of the plants was also observed in a greenhouse after the incubation of tubers in wet conditions.ResultsWet conditions induced a low-oxygen response, suggesting reduced oxygen availability in wet tubers at both temperatures when compared to that in the corresponding dry samples. Wet conditions induced genes coding for heat shock proteins, as well as proteins involved in fermentative energy production and defense against reactive oxygen species (ROS), which are transcripts that have been previously associated with low-oxygen stress in hypoxic or anoxic conditions. Wet treatment also induced senescence-related gene expression and genes involved in cell wall loosening, but downregulated genes encoding protease inhibitors and proteins involved in chloroplast functions and in the biosynthesis of secondary metabolites. Many genes involved in the production of phytohormones and signaling were also affected by wet conditions, suggesting altered regulation of growth by wet conditions. Hormone measurements after incubation showed increased salicylic acid (SA), abscisic acid (ABA) and auxin (IAA) concentrations as well as reduced production of jasmonate 12-oxo-phytodienoic acid (OPDA) in wet tubers. After incubation in wet conditions, the tubers produced fewer stems and more roots compared to controls incubated in dry conditions.ConclusionsIn wet conditions, tubers invest in ROS protection and defense against the abiotic stress caused by reduced oxygen due to excessive water. Changes in ABA, SA and IAA that are antagonistic to jasmonates affect growth and defenses, causing induction of root growth and rendering tubers susceptible to necrotrophic pathogens. Water on the tuber surface may function as a signal for growth, similar to germination of seeds.
  • Alonso Serra, Juan Antonio; Shi, Xueping; Peaucelle, Alexis; Rastas, Pasi; Bourdon, Matthieu; Immanen, Juha; Takahashi, Junko; Koivula, Hanna; Eswaran, Gugan; Muranen, Sampo Johannes; Help-Rinta-Rahko, Hanna; Smolander, Olli-Pekka; Su, Chang; Safronov, Omid; Gerber, Lorenz; Salojärvi, Jarkko; Hagqvist, Risto; Mähönen, Ari Pekka; Helariutta, Yrjö; Nieminen, Kaisa (2020)
    Tree architecture has evolved to support a top-heavy above-ground biomass, but this integral feature poses a weight-induced challenge to trunk stability. Maintaining an upright stem is expected to require vertical proprioception through feedback between sensing stem weight and responding with radial growth. Despite its apparent importance, the principle by which plant stems respond to vertical loading forces remains largely unknown. Here, by manipulating the stem weight of downy birch (Betula pubescens) trees, we show that cambial development is modulated systemically along the stem. We carried out a genetic study on the underlying regulation by combining an accelerated birch flowering program with a recessive mutation at the ELIMAKI locus (EKI), which causes a mechanically defective response to weight stimulus resulting in stem collapse after just 3 months. We observed delayed wood morphogenesis in eki compared with WT, along with a more mechanically elastic cambial zone and radial compression of xylem cell size, indicating that rapid tissue differentiation is critical for cambial growth under mechanical stress. Furthermore, the touch-induced mechanosensory pathway was transcriptionally misregulated in eki, indicating that the ELIMAKI locus is required to integrate the weight-growth feedback regulation. By studying this birch mutant, we were able to dissect vertical proprioception from the gravitropic response associated with reaction wood formation. Our study provides evidence for both local and systemic responses to mechanical stimuli during secondary plant development.
  • Fernandez-Llamazares, Alvaro; Lepofsky, Dana (2019)
    Music is recognized as an essential constituent of the diversity of life on Earth and is enshrined in the concept of biocultural diversity. While research shows that song is an untapped library of biocultural memory, ethnobiologists have not yet explored the many areas in which studying songs and music through an ethnobiological lens could bring into focus the multi-dimensional relationships among humans and their biological worlds. 'the research articles in this special issue illustrate the importance of songs as both a repository of ethnobiological knowledge and as a means to construct, maintain, and mobilize peoples' intimate relations with their local ecologies. Although many traditional music-making systems are under risk of attrition, the extent to which traditional songs continue to be performed and celebrated in many Indigenous and local communities attests not just to the endurance and resilience of their cultures, but also to their deep cultural attachment to their lands as manifested through song. this special issue constitutes one significant step towards the recognition of music both as a timeless prism for looking at human-nature inter-relations, in all their complexities and magnificence, and as an essential form of biocultural heritage, worthy of documentation, conservation, and revitalization.
  • Kolari, Pasi; Chan, Tommy; Porcar-Castell, Albert; Back, Jaana; Nikinmaa, Eero; Juurola, Eija (2014)
  • Othmani, Ahmed; Collin, Myriam; Sellemi, Amel; Jain, Shri Mohan; Drira, Noureddine; Aberlenc, Frederique (2017)
    The date palm (Phoenix dactylifera L.) is dioecious with male flowers deficient in functional gynoecium and female flowers deficient in functional androecium borne on separate palms. The presence of male and female flowers on the same plant, a phenomenon known as monoecy, is unusual in male date palms. This study reports for the first time on hermaphrodite (bisexual) flowers borne by two female date palms, 'Alligue', that were found growing in an open field in Degache, southern Tunisia. The observations on these two female palms were compared with hermaphrodite male date palms growing in the same location. Hermaphrodite female date palm inflorescence branches bear female flowers predominantly near their base, in contrast to the hermaphrodite flowers that are found primarily toward their upper part. The position of the hermaphrodite flowers in hermaphrodite male date palms is reversed: inflorescence branches bear male flowers toward the upper part while the hermaphrodite flowers are found at the base. Histological examination of female hermaphrodite flowers revealed that they had three carpels and 1-6 stamens. Hermaphrodite flowers on male plants were usually also composed of three carpels of variable size, and six stamens. Hermaphrodite flowers on both female and male palm trees turn generally into parthenocarpic fruits. The present data support the theory that dioecious plants are derived from a common hermaphrodite ancestor. Floral hermaphroditism in date palm should be investigated in relation to the in planta self-fertilization process to identify sex markers and genes that control sex organ development.
  • Mganga, Kevin Z.; Ndathi, Aphaxard J. N.; Wambua, Stephen M.; Bosma, Luwieke; Kaindi, Eric M.; Kioko, Theophilus; Kadenyi, Nancy; Musyoki, Gilbert K.; van Steenbergen, Frank; Musimba, Nashon K. R. (2021)
    Context. Rangeland grasses native to Africa constitute the main diet for free-ranging livestock and wild herbivores. Leaf:stem ratio is a key characteristic used for assessing quality of forages. However, studies to determine the allocation of biomass to leaves and stems as well as chemical components and nutritive value, especially of grasses in African rangelands, are rare. Aim. This study was conducted to establish biomass allocation and chemical and mineral components in leaf and stem fractions of three grasses, Eragrostis superba, Enteropogon macrostachyus and Cenchrus ciliaris, all indigenous to African rangelands. Methods. Plant height, plant densities, plant tiller densities and biomass yields were estimated at the elongation stage, before inflorescence. Chemical and mineral components were determined from biomass harvested at the vegetative phase for all three grass species. Dry matter, ash content, organic matter, crude protein, neutral detergent fibre, acid detergent fibre, acid detergent lignin, and calcium, phosphorus and potassium contents were determined. Key results. Enteropogon macrostachyus displayed significantly greater plant and tiller densities and plant height than the other two species. Leaf and stem biomass fractions varied significantly (P <0.05) among grasses. Leaf:stem ratio of E. superba was double that of E. macrostachyus and C. ciliaris. Crude protein and organic matter yields and net energy for lactation were highest (P <0.05) in E. superba leaf biomass, as was Ca content. Conclusions. Eragrostis superba demonstrated greater potential as a forage species for ruminant animal production than E. macrostachyus and C. ciliaris. Implications. Eragrostis superba is a key forage species that warrants promotion in pasture establishment programs in its native environments.
  • Kontturi, Juha; Osama, Raisa; Deng, Xianbao; Bashandy, Hany; Albert, Victor A.; Teeri, Teemu H. (2017)
    The chalcone synthase superfamily consists of type III polyketidesynthases (PKSs), enzymes responsible for producing plant secondary metabolites with various biological and pharmacological activities. Anther-specific chalcone synthase-like enzymes (ASCLs) represent an ancient group of type III PKSs involved in the biosynthesis of sporopollenin, the main component of the exine layer of moss spores and mature pollen grains of seed plants. In the latter, ASCL proteins are localized in the tapetal cells of the anther where they participate in sporopollenin biosynthesis and exine formation within the locule. It is thought that the enzymes responsible for sporopollenin biosynthesis are highly conserved, and thus far, each angiosperm species with a genome sequenced has possessed two ASCL genes, which in Arabidopsis thaliana are PKSA and PKSB. The Gerbera hybrida (gerbera) PKS protein family consists of three chalcone synthases (GCHS1, GCHS3 and GCHS4) and three 2-pyrone synthases (G2PS1, G2PS2 and G2PS3). In previous studies we have demonstrated the functions of chalcone synthases in flavonoid biosynthesis, and the involvement of 2-pyrone synthases in the biosynthesis of antimicrobial compounds found in gerbera. In this study we expanded the gerbera PKS-family by functionally characterizing two gerbera ASCL proteins. In vitro enzymatic studies using purified recombinant proteins showed that both GASCL1 and GASCL2 were able to use medium and long-chain acyl-CoA starters and perform two to three condensation reactions of malonyl-CoA to produce tri- and tetraketide 2-pyrones, usually referred to as alpha-pyrones in sporopollenin literature. Both GASCL1 and GASCL2 genes were expressed only floral organs, with most expression observed in anthers. In the anthers, transcripts of both genes showed strict tapetum-specific localization. (C) 2016 Elsevier Ltd. All rights reserved.