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Due to its ancient origin in the Permian and the high proportion of beetle-pollinated taxa within ancestral magnoliid lineages, it has been hypothesized that beetles were among the first floral visitors of the proto-angiosperms on Earth. Thus, beetle-pollinated flowers have become important model systems essential for the study of the origin and evolution of angiosperms. Under an evolutionary perspective, in this review we synthesize what is currently known about beetles as floral visitors in the family Magnoliaceae, one of the earliest extant groups of flowering plants. Nitidulidae and Scarabaeidae are the two most common groups of beetles reported in the literature as floral visitors to Magnoliaceae; however, the evidence indicates that most modern families of beetles including all the families with known taxa associated with Magnoliaceae had already originated when the latter first appeared by the end of the early Cretaceous. Hence, Magnoliaceae could have represented a newly opened ecological niche that beetles gradually colonized and exploited, possibly shifting from gymnosperm hosts. By feeding, mating and sheltering in their flower structures, beetles have played a major role in shaping the floral biology and morphology of Magnoliaceae. Protogyny, thermogenesis, floral odors and floral movements are traits that could have evolved in response to selection pressures imposed by beetles. Further studies should assess the possible role of anthophagous scarabs (subfamilies Cetoniinae, Melolonthinae, Dynastinae and Rutelinae) in the diversification of Magnoliaceae, since this event broadly coincides with the origin of those groups of beetles in the Eocene, some of which exhibit very close associations with several Magnoliaceae species.

Naturally-occurring membranes in the xylem tissue of gymnosperm sapwood enable its use as an abundantly-available material to construct filters, with potential to facilitate access to safe drinking water in resource-constrained settings. However, the material’s behavior as a filter is poorly understood, and challenges such as short shelf life have not been addressed. Here, we characterize the operational attributes of xylem filters and show that the material exhibits a highly non-linear dependence of flow resistance on thickness upon drying, and a tendency for self-blocking. We develop guidelines for the design and fabrication of xylem filters, demonstrate gravity-operated filters with shelf life >2 years, and show that the filters can provide >3 log removal of E. coli, MS-2 phage, and rotavirus from synthetic test waters and coliform bacteria from contaminated spring, tap, and ground waters. Through interviews and workshops in India, we use a user-centric approach to design a prototype filtration device with daily- to weekly-replaceable xylem filters, and uncover indicators of social acceptance of xylem as a natural water filter. Our work enhances the understanding of xylem as a filtration material, and opens opportunities for engineering a diverse range of low-cost, biodegradable xylem-based filtration products on a global scale., Gymnosperm sapwood is an abundantly available material to construct water filters but the material’s behaviour as a filter is poorly understood and challenges such as short shelf live have not been addressed. Here, the authors develop guidelines for the design and fabrication of xylem filters and demonstrate gravity-operated filters with a shelf life of more than two years for the removal of contaminants from spring, tap and ground water.

It was given the systematical, florogenetical and ecobiomorphological analysis of representatives of Gymnosperm division belonged to Odessa dendroflora. The information about their ecological peculiarities (smogstable, the attitude to soil composition) has been presented. The list of the plants widely used in green building has been submitted., Дан систематический, флорогенетический и экобиоморфологический аналіз представителей отдела Голосеменные, встречающихся в дендрофлоре г. Одессы. Приведена информация об их экологических особенностях (газо- и дымостойкость, отношение к составу почв). Представлен список растений, широко используемых в зелёном строительстве., Проведено систематичний, флорогенетичний та екобіоморфологічний аналіз представників відділу Голонасінні, що зустрічаються у дендрофлорі м. Одеси. Наведена інформація про їхні екологічні особливості (газо- і димостійкість, відношення до складу ґрунтів). Представлено список рослин, що найширше використовуються у зеленому будівництві.

Homologs of Larix kaempferiDEFICIENS-AGAMOUS-LIKE 1 (LaDAL1) promote flowering in Arabidopsis. However, their functional role in the whole life-cycle is limited. Here, we analyzed the phenotypes and transcriptomes of Arabidopsis plants over-expressing LaDAL1. With respect to the defined life-cycle stage of Arabidopsis based on the meristem state, the results showed that LaDAL1 promoted seed germination, bolting, flower initiation, and global proliferative arrest, indicating that LaDAL1 accelerates the meristem reactivation, the transitions of vegetative meristem to inflorescence and flower meristem, and meristem arrest. As a marker gene of meristem, TERMINAL FLOWER 1 was down-regulated after LaDAL1 over-expression. These results reveal that LaDAL1 accelerates the life-cycle progression in Arabidopsis by promoting the transition of meristem fate, providing more and novel functional information about the conifer age-related gene DAL1.

The DELAY OF GERMINATION1 (DOG1) family genes (DFGs) in Arabidopsis thaliana are involved in seed dormancy, reserve accumulation, and desiccation tolerance. Decoding the molecular evolution of DFGs is key to understanding how these seed programs evolved. This article demonstrates that DFGs have diverged in the four lineages DOG1, DOG1-LIKE4 (DOGL4), DOGL5 and DOGL6, whereas DOGL1, DOGL2 and DOGL3 arose separately within the DOG1 lineage. The systematic DFG nomenclature proposed in this article addresses the current issues of inconsistent DFG annotation and highlights DFG genomic synteny in angiosperms. DFG pseudogenes, or collapsed coding sequences, hidden in the genomes of early-diverging angiosperms are documented here. They suggest ancient birth and loss of DFGs over the course of angiosperm evolution. The proposed models suggest that the origin of DFG diversification dates back to the most recent common ancestor of living angiosperms. The presence of a single form of DFG in nonflowering plants is discussed. Phylogenetic analysis of gymnosperm, lycophyte, and liverwort DFGs and similar genes found in mosses and algae suggests that DFGs diverged from the TGACG motif-binding transcription factor genes before the divergence of the bryophyte lineage.

Cell wall thickness (Tcw) determines photosynthesis and leaf elasticity. However, only a few studies in angiosperms addressed cell wall composition implication in regulating photosynthesis and leaf water relations through mesophyll conductance (gm) and bulk modulus of elasticity (e) adjustments, respectively. Thus, we compared the phylogenetically distant Ginkgo biloba L. and Helianthus annuus L. under control and water deprivation to study the relationship between changes in cell wall composition (cellulose, hemicelluloses, and pectins) with gm and e. Although no changes were found for Tcw, both species differently modified cell wall composition, resulting in different physiological consequences. H. annuus increased cellulose, hemicelluloses, and pectins in a similar proportion, maintaining e. Additionally, it reduced photosynthesis due to stomatal closure. G. biloba did not decrease photosynthesis and largely increased hemicelluloses, leaf mass area, and leaf density, enhancing e. Nonetheless, no association between cell wall composition and gm was found in either of the two species.

The giant sequoia (Sequoiadendron giganteum) of California are massive, long-lived trees that grow along the U.S. Sierra Nevada mountains. Genomic data are limited in giant sequoia and producing a reference genome sequence has been an important goal to allow marker development for restoration and management. Using deep-coverage Illumina and Oxford Nanopore sequencing, combined with Dovetail chromosome conformation capture libraries, the genome was assembled into eleven chromosome-scale scaffolds containing 8.125 Gbp of sequence. Iso-Seq transcripts, assembled from three distinct tissues, was used as evidence to annotate a total of 41,632 protein-coding genes. The genome was found to contain, distributed unevenly across all 11 chromosomes and in 63 orthogroups, over 900 complete or partial predicted NLR genes, of which 375 are supported by annotation derived from protein evidence and gene modeling. This giant sequoia reference genome sequence represents the first genome sequenced in the Cupressaceae family, and lays a foundation for using genomic tools to aid in giant sequoia conservation and management.

Epigenetic reprogramming during germ cell formation is essential to gain pluripotency and thus embryogenic potential. The histone modification H3K27me3, which is catalysed by the Polycomb repressive complex 2 (PRC2), regulates important developmental processes in both plants and animals, and defects in PRC2 components cause pleiotropic developmental abnormalities. Nevertheless, the role of H3K27me3 in determining embryogenic potential in gymnosperms is still elusive. To address this, we generated H3K27me3 profiles of Norway spruce (Picea abies) embryonic callus and non-embryogenic callus using CUT&RUN, which is a powerful method for chromatin profiling. Here, we show that H3K27me3 mainly accumulated in genic regions in the Norway spruce genome, similarly to what is observed in other plant species. Interestingly, H3K27me3 levels in embryonic callus were much lower than those in the other examined tissues, but markedly increased upon embryo induction. These results show that H3K27me3 levels are associated with the embryogenic potential of a given tissue, and that the early phase of somatic embryogenesis is accompanied by changes in H3K27me3 levels. Thus, our study provides novel insights into the role of this epigenetic mark in spruce embryogenesis and reinforces the importance of PRC2 as a key regulator of cell fate determination across different plant species., PRC2-mediated H3K27me3 is associated with embryogenic potential in Norway spruce, and the early phase of somatic embryogenesis is accompanied by changes in H3K27me3 levels.

The genusOsmundaL. contains approximately 10 extant species widely distributed in tropical and temperate regions, with the greatest concentration of species in East and Southeast Asia.Osmundais characterized by dimorphic or commonly hemidimorphic fronds with dimorphic pinnae. Its geological history has been traced back to the Triassic. Most records of the genus are based on rhizomes and rarely on pinnae bearing sporangia and spores. Here, we describe fossil pinnae, sporangia, and spores ofOsmunda lignitum(Giebel) Stur recovered from the middle Eocene of the Changchang Formation in the Changchang Basin, Hainan Island and the Youganwo Formation in the Maoming Basin, Guangdong, South China. The fossils closely resemble the extantOsmunda banksiifolia(C. Presl) Kuhn of the subgenusPlenasiumon the basis of their morphological and anatomical structures. The present occurrence ofO. lignitumindicates subg.Plenasiumflourished and extended from the high latitude regions such as Northeast China to the low latitude areas of South China during the middle Eocene. Large numbers of specimens described here also indicate thatOsmundawas the dominant understory fern element beneath mixed evergreen broad-leaf angiosperm and gymnosperm forests living in a warm and humid environment.

The pollination drop (PD), also known as an ovular secretion, is a critical feature of most wind-pollinated gymnosperms and function as an essential component of pollination systems. However, the metabolome and small RNAs of gymnosperm PDs are largely unknown. We employed gas chromatography–mass spectrometry to identify a total of 101 metabolites in Ginkgo biloba L. PDs. The most abundant metabolites were sugars (45.70%), followed by organic acids (15.94%) and alcohols (15.39%) involved in carbohydrate metabolism, glycine, serine and threonine metabolism. Through pollen culture of the PDs, we further demonstrated that the metabolic components of PDs are indispensable for pollen germination and growth; in particular, organic acids and fatty acids play defensive roles against microbial activity. In addition, we successfully constructed a small RNA library and detected 45 known and 550 novel miRNAs in G. biloba PDs. Interestingly, in a comparative analysis of miRNA expression between PDs and ovules, we found that most of the known miRNAs identified in PDs were also expressed in the ovules, implying that miRNAs in PDs may originate from ovules. Further, combining with potential target prediction, degradome validation and transcriptome sequencing, we identified that the interactions of several known miRNAs and their targets in PDs are involved in carbohydrate metabolism, hormone signaling and defense response pathways, consistent with the metabolomics results. Our results broaden the knowledge of metabolite profiling and potential functional roles in gymnosperm PDs and provide the first evidence of extracellular miRNA functions in ovular secretions from gymnosperms.

Continuing the study of petrified gymnosperm trunks recovered from the Pedra de Fogo Formation, we identify here two new taxa from the Permian deposits of the Parnaiba Basin, northeastern Brazil. One taxon is an endemic form named Ductolobatopitys mussae Conceicao, Neregato et Iannuzzi, nov. gen., nov. sp., characterized by solenoid, lobed and non-septate heterocellular pith, cauline bundles with endarch maturation, and secondary xylem with araucarian radial pitting on the tracheid walls. The other form is assigned to the genus Kaokoxylon, which has been recorded from most of Gondwana, including the Parnaiba Basin, but is recorded for the first time from the Pedra de Fogo Formation with the new species Kaokoxylon brasiliensis. It is characterized by solid, non-septate heterocellular pith with sclerenchyma cells, endarch cauline bundles, and uni-to triseriate radial pitting on the walls of the tracheids. The sedimentological interpretations of the outcrops where the fossils were collected indicate that these plants lived on the shores of large continental lakes, with relatively high humidity but possibly periods of drought. These inferences are supported by growth interruptions in the secondary xylem, the presence of calamitalean and tree-fern stems, and microbialites that crop in the same area. These new finds not only increase the known diversity of the flora in the Pedra de Fogo Formation, but also provide more accurate information for understanding the floristic elements that formed the subtropical flora during the Cisuralian in this basin in Western Gondwana.

Plant mitochondrial genomes vary widely in size. Although many plant mitochondrial genomes have been sequenced and assembled, the vast majority are of angiosperms, and few are of gymnosperms. Most plant mitochondrial genomes are smaller than a megabase, with a few notable exceptions. We have sequenced and assembled the complete 5.5-Mb mitochondrial genome of Sitka spruce (Picea sitchensis), to date, one of the largest mitochondrial genomes of a gymnosperm. We sequenced the whole genome using Oxford Nanopore MinION, and then identified contigs of mitochondrial origin assembled from these long reads based on sequence homology to the white spruce mitochondrial genome. The assembly graph shows a multipartite genome structure, composed of one smaller 168-kb circular segment of DNA, and a larger 5.4-Mb single component with a branching structure. The assembly graph gives insight into a putative complex physical genome structure, and its branching points may represent active sites of recombination.

Since historical buildings are living mirrors of the past, it is very important to preserve and transfer them to future generations. In this study, plants growing on the walls of Alanya Castle were identified and the damages that these plants gave to the historical construction and the precautions to be taken to prevent these damages were emphasized. A total of 94 plant taxa, including five pteridophytes, one gymnosperm and 88 angiosperms, belonging to 35 families were identified on the walls of Alanya Castle. Conyza canadensis, Inula heterolepis, Phagnalon graecum, Arabis verna, Mercurialis annua, Fumaria parviflora, Cymbalaria microcalyx, Galium canum subsp. antalyense, Parietaria judaica, Hyoscyamus aureus, Poa bulbosa were the dominant plant species of Alanya Castle walls. Possible seed dispersion of these plants on the castle walls and the methods for controlling them are discussed in detail. We conclude that the most effective method of combating plants that grow naturally on historical buildings and give damage to these buildings is mechanical excavation.

Background Plant dispersal units, or diaspores, allow the colonization of new environments expanding geographic range and promoting gene flow. Two broad categories of diaspores found in seed plants are dry and fleshy, associated with abiotic and biotic dispersal agents, respectively. Anatomy and developmental genetics of fleshy angiosperm fruits is advanced in contrast to the knowledge gap for analogous fleshy structures in gymnosperm diaspores. Improved understanding of the structural basis of modified accessory organs that aid in seed dispersal will enable future work on the underlying genetics, contributing to hypotheses on the origin of angiosperm fruits. To generate a structural framework for the development and evolution of gymnosperm fleshy diaspores, we studied the anatomy and histochemistry of Ephedra (Gnetales) seed cone bracts, the modified leaves surrounding the reproductive organs. We took an ontogenetic approach, comparing and contrasting the anatomy and histology of fleshy and papery-winged seed cone bracts, and their respective pollen cone bracts and leaves in four species from the South American clade. Results Seed bract fleshiness in Ephedra derives from mucilage accumulated in chlorenchyma cells, also found in the reduced young leaves before they reach their mature, dry stage. Cellulosic fibers, an infrequent cell type in gymnosperms, were found in Ephedra, where they presumably function as a source of supplementary apoplastic water in fleshy seed cone bracts. Papery-winged bract development more closely resembles that of leaves, with chlorenchyma mucilage cells turning into tanniniferous cells early on, and hyaline margins further extending into “wings”. Conclusions We propose an evolutionary developmental model whereby fleshy and papery-winged bracts develop from an early-stage anatomy shared with leaves that differs at the pollination stage. The ancestral fleshy bract state may represent a novel differentiation program built upon young leaf anatomy, while the derived dry, papery-winged state is likely built upon an existing differentiation pattern found in mature vegetative leaves. This model for the evolution of cone bract morphology in South American Ephedra hence involves a novel differentiation program repurposed from leaves combined with changes in the timing of leaf differentiation, or heterochrony, that can further be tested in other gymnosperms with fleshy diaspores.

Tree-ring inter-annual pattern variation is crucial in dendrochronology, allowing the identification of possible limiting factors on growth. Thus, trees exposed to subtropical or tropical climates without a marked seasonality may show a low degree of interannual variation, impeding a straightforward dendroclimatological approach. Meanwhile, subtropical regions, and areas in transitional climates such as the Azores archipelago, are widely unexplored in terms of dendroclimatology, providing opportunities to work with endemic trees, including the dominant Azorean tree Juniperus brevifolia (Seub.) Antoine. To evaluate the dendrochronological potential of J. brevifolia, we analyzed tree-ring patterns, crossdating capabilities, and correlation with climate parameters. We sampled 48 individual trees from two natural populations (São Miguel and Terceira islands) using an increment borer. Besides, a Trephor tool was used to obtain wood microcores for micro-anatomical analysis. Although the transition between early and latewood was evident, partially indistinct ring boundaries and wedging rings were present in some cases, affecting the crossdating process, but not impeding the establishment of reliable ring-width chronologies. Following detrending, master chronologies were built and correlated with monthly temperature and precipitation data using the treeclim R package. The climate-growth relationships indicated negative correlations with late summer temperature in both populations. Considering our results and the importance of J. brevifolia as a dominant tree in the Azores natural forests, we conclude that it shows an acceptable potential for dendrochronological research. Thus, this study provides baseline information to help fill the knowledge gap regarding the climate-growth relationship of Azorean trees. Diogo C. Pavão is currently supported by a PhD studentship grant (SFRH/BD/136336/2018) from Fundação para a Ciência e Tecnologia (FCT) , Ministério da Ciência, Tecnologia e Ensino Superior. This research was also supported by the Azores Gov-ernment-DRCT-M1.1.a/015/Funcionamento/2020 (CIBIO-A) ; by FEDER funds through the Operational Program for Competitiveness Factors-COMPETE and by National Funds through FCT-Foundation for Science and Technology under the (FCT) UIDB/50027/2020 (CIBIO) and (FCT) UIDP/50027/2020 (CIBIO) . This work was also funded by FEDER in 85% and by Azorean Public funds by 15% through Operational Program Azores 2020, under the project AZORESBIOPORTAL - POR-BIOTA (ACORES-01-0145-FEDER-000072) . J. Jevšenak was supported by the European Forest Institute Short Scientific Visit grant and Slove-nian Research Agency (P4-0107) . info:eu-repo/semantics/publishedVersion

For most of the Phanerozoic Eon, Earth’s woody vegetation has been dominated by C3 plants - predominantly gymnosperms - with angiosperms only emerging as the dominant plant group as CO2 declined during the Cenozoic (66 Ma onward). At present, differences in carbon isotope discrimination ( Δ 13 C ) between angiosperm and gymnosperm plants are relatively small (2–3 ‰), but an increasing body of evidence points to larger differences across geological times (up to 6–7 ‰), potentially associated with varying environmental conditions and atmospheres (i.e. concentrations of atmospheric carbon dioxide, [CO2], and oxygen, [O2] could have ranged from ∼ 180 to 1100 ppm, and ∼ 15 to 25%, respectively, across the past 250 Ma). Yet, differences in Δ 13 C between the two plant groups, and their potential link to climatic and environmental changes, have not yet been fully explored and understood. Here, we combine a comprehensive ab initio model of discrimination, with a recent model of plant eco-physiology based on least-cost optimality theory, to show how differences in Δ 13 C between angiosperms and gymnosperms arise. We train the comprehensive model using a very large ( n > 7000 ) database of leaf and tree ring data spanning the past 110 years. We find that averaged differences in Δ 13 C between angiosperm and gymnosperms decrease modestly with atmospheric [O2]:[CO2] ratios, and increase strongly with vapor pressure deficit (D). These relationships can be explained by three key physiological differences: (1) the ratio of cost factors for transpiration to carboxylation (higher in angiosperms); (2) the ratio of mesophyll to stomatal conductances of CO2 (lower in gymnosperms); and (3) differences in photorespiration. In particular, the amount of CO2 released from photorespiration per oxygenation reaction, λ , is generally lower in gymnosperms than in angiosperms. As a result of these factors, Δ 13 C is more sensitive to [CO2] in angiosperms, and to D in gymnosperms. We propose a simplified empirical model to account for this behaviour, and test it against isotopic data from leaves, tree rings and previously-published plant chamber experiments, along with geological data from the Cenozoic. Overall, these data agree with our model over a range of [O2]:[CO2] ratios from 100 to 650 mol mol−1 (equivalent to a CO2 range around 323–2100 ppm at 21% O2), and D levels between 0.45 and 1.1 kPa (R2 = 0.51, RMSE = 1.49 ‰). Our simplified empirical model offers a new explanation for secular trends in the geological record, and suggests a way forward to improve paleo-[CO2] proxies based on terrestrial discrimination models by incorporating the effects of [O2], phylogeny, and photorespiration. Lastly, the framework predicts that the average difference in Δ 13 C between woody C3 plant groups will increase in the future if both [CO2] and global D continue to rise as suggested by projections.

ÖZETNEZAHAT GÖKYİĞİT BOTANİK BAHÇESİ GYMNOSPERMLERİÜZERİNDE PALİNOLOJİK ARAŞTIRMALARTürkiye gerek coğrafi konumu gerekse iklim özellikleri nedeniyle, dünyanın en zenginbitki çeşitliliğine sahip ülkelerden biridir. Bu çeşitlilik içinde Gymnospermler de önemlibir yer tutmaktadır. Çoğu bitkide olduğu gibi hem doğal bir zenginlik ve hem deekonomik önemi olan Gymnospermlerin çeşitli özelliklerinin tanımlanması, kaynaklarınkayda geçirilmesi ve korunması büyük öneme sahiptir. Bitkilerde klasik morfolojiktanımlamalar yanında polen morfolojilerinin (polen boyutu, polen şekli, polenaçıklıklarının tipi ve sayısı, polen dış çeperi ekzinin yüzey özellikleri vb.) mikroskobik(ışık-elektron) yöntemler kullanılarak belirlenmesi de yaygın olarak kullanılmaktadır.Elde edilen polen morfolojisi ile ilgili veriler bitki sistematiği alanının yanı sıra bölgeselpolen dağılımı, geçmişte ve devam eden iklim değişiklikleri, arkeolojik-jeolojik kayıtlar,coğrafik veriler, alerjik-solunum rahatsızlıkları ve polen ürünlerinin (bal vb.) kalitesikonularında da değerlendirilmektedir. Yapılan literatür taramaları ve takip edilen listelerebakıldığında, çalışmaların çoğunda Angiospermlere ait palinolojik özelliklerinvurgulandığı görülmüştür. Bu nedenle bu tez çalışması, Nezahat Gökyiğit BotanikBahçesi (NGBB) Gymnospermleri üzerinde yoğunlaşarak palinolojik açıdanmikroskobik incelemeler yapılmasını amaçlamaktadır. Gymnosperm türlerine ait polenlerNGBB’de var olan ağaçlardan temin edilmiştir. Cupressaceae ve Pinaceae familyalarınaait 15 taksona ait polen taneleri Wodehouse yöntemi kullanılarak ışık mikroskobudüzeyinde incelenmiştir. Elde edilen sonuçlara göre Cupressaceae familyasına ait türlersferoidal şekilli ve granulat yüzey ornamentasyonlu, Pinaceae familyasına ait türler ise 2adet hava kesesi içeren verrukat veya skabrat yüzey ornamentasyonlu olduğubelirlenmiştir. Bu polen örneklerinin ait olduğu taksonların bir kısmı palinolojiközellikleri daha önce hiç kayda alınmamıştır. Elde ettiğimiz ışık mikroskobu verilerininuzun vadede Türkiye’deki biyolojik çeşitliliğin kayda alınması, polen atlasının veanahtarının oluşturulmasına da katkı sağlayacağı da düşünülmektedir.ABSTRACTPALYNOLOGICAL INVESTIGATIONS ON GYMNOSPERMS OF NEZAHATGÖKYİĞİT BOTANICAL GARDENDue to its geographical location and climatic characteristics, Turkey is one of thecountries with the richest plant diversity in the world. Gymnosperms also have animportant place in this diversity. As with most plants, the identification of variouscharacteristics of Gymnosperms, which have both natural richness and economicimportance, is of great importance in terms of recording and protecting resources. Inaddition to classical morphological definitions in plants, the determination of pollenmorphology (pollen size, pollen shape, type and number of pollen openings, surfaceproperties of pollen outer wall excise, etc.) using microscopic (light-electron) methods isalso widely used. In addition to the field of plant systematics, the obtained data on pollenmorphology are also evaluated on regional pollen distribution, past and ongoing climatechanges, archaeological-geological records, geographical data, allergic-respiratorydisorders and quality of pollen products (honey, etc.). When the literature reviews and thelists followed, it was seen that the palynological features of Angiosperms wereemphasized in most of the studies. For this reason, this thesis study focuses on NezahatGökyiğit Botanical Garden (NGBB) Gymnosperms and aims to make microscopicexaminations from a palynological point of view. Pollens belonging to Gymnospermspecies were obtained from trees existing in NGBB. Pollen grains belonging to 15 taxabelonging to Cupressaceae and Pinaceae families were examined at the light microscopelevel using the Wodehouse method. According to the results obtained, the speciesbelonging to the Cupressaceae family were determined to be spheroidal shaped andgranulate surface ornamentation, while the species belonging to the Pinaceae family weredetermined to have verrucate or scabrate surface ornamentation containing 2 air sacs. Thepalynological features of some of the taxa to which these pollen samples belong havenever been recorded before. It is also thought that the light microscopy data we haveobtained will contribute to the recording of biological diversity in Turkey and the creationof the pollen atlas and key in the long term.

The leafminers on gymnosperms receive much less attention than those on either angiosperms or ferns. Given the distinctly different leaf shape and leaf venation found in gymnosperms, they would be expected to host significantly different leafminer groups. Very few comprehensive reports on gymnosperm-feeding leafminers have been presented.Based on the well-studied fauna in North America and Europe, we compiled a list of 133 species, 30 genera and 13 families of gymnosperm-feeding leafminers. The gymnosperm-mining families (in descending order of leafminer number) included Tortricidae, Gelechiidae, Argyresthiidae, Yponomeutidae, Batrachedridae, Pyralidae, Adelidae, Agromyzidae, Blastobasidae, Bucculatricidae, Coleophoridae, Curculionidae and Noctuidae. There were 109 species, 22 genera and ten families in North America and 34 species, 19 genera and nine families in Europe. We compiled a list of 102 species and 16 genera of host plants, belonging to four families: Pinaceae, Cupressaceae, Taxaceae and Zamiaceae. There were 84 host species, 15 genera and three host families in North America and 46 host species, ten genera and three host families in Europe. Dominant gymnosperm-mining families and dominant host families were generally the same in the two continents.

Plastid genomes (plastomes) have a quadripartite structure, but some species have drastically reduced or lost inverted repeat (IR) regions. IR regions are important for genome stability and the evolution rate. In the evolutionary process of gymnosperms, the typical IRs of conifers were lost, possibly affecting the evolutionary rate and selection pressure of genomic protein‐coding genes. In this study, we selected 78 gymnosperm species (51 genera, 13 families) for evolutionary analysis. The selection pressure analysis results showed that negative selection effects were detected in all 50 common genes. Among them, six genes in conifers had higher ω values than non‐conifers, and 12 genes had lower ω values. The evolutionary rate analysis results showed that 9 of 50 common genes differed between conifers and non‐conifers. It is more obvious that in non‐conifers, the rates of psbA (trst, trsv, ratio, dN, dS, and ω) were 2.6‐ to 3.1‐fold of conifers. In conifers, trsv, ratio, dN, dS, and ω of ycf2 were 1.2‐ to 3.6‐fold of non‐conifers. In addition, the evolution rate of ycf2 in the IR was significantly reduced. psbA is undergoing dynamic change, with an abnormally high evolution rate as a small portion of it enters the IR region. Although conifers have lost the typical IR regions, we detected no change in the substitution rate or selection pressure of most protein‐coding genes due to gene function, plant habitat, or newly acquired IRs., There are significant differences in the selection pressure of 12 genes and the evolution rate of 9 genes between conifer and non‐conifer. This difference seems to be not related to the loss of typical IR regions but related to habitat. And the newly obtained short IR region plays a role in stabilizing the genome. The ycf2 located in the IR region showed a reduced substitution rate, providing evidence for the IR region a reduced substitution rate. PsbA is undergoing dynamic changes, and part of it enters the IR region, showing an abnormally high substitution rate.

Background R2R3-MYB is a class of transcription factor crucial in regulating secondary cell wall development during wood formation. The regulation of wood formation in gymnosperm has been understudied due to its large genome size. Using Single-Molecule Real-Time sequencing, we obtained full-length transcriptomic libraries from the developmental stem of Cunninghamia lanceolata, a perennial conifer known as Chinese fir. The R2R3-MYB of C. lanceolata (hereafter named as ClMYB) associated with secondary wall development were identified based on phylogenetic analysis, expression studies and functional study on transgenic line. Results The evolutionary relationship of 52 ClMYBs with those from Arabidopsis thaliana, Eucalyptus grandis, Populus trichocarpa, Oryza sativa, two gymnosperm species, Pinus taeda, and Picea glauca were established by neighbour-joining phylogenetic analysis. A large number of ClMYBs resided in the woody-expanded subgroups that predominated with the members from woody dicots. In contrast, the woody-preferential subgroup strictly carrying the members of woody dicots contained only one candidate. The results suggest that the woody-expanded subgroup emerges before the gymnosperm/angiosperm split, while most of the woody-preferential subgroups are likely lineage-specific to woody dicots. Nine candidates shared the same subgroups with the A. thaliana orthologs, with known function in regulating secondary wall development. Gene expression analysis inferred that ClMYB1/2/3/4/5/26/27/49/51 might participate in secondary wall development, among which ClMYB1/2/5/26/27/49 were significantly upregulated in the highly lignified compression wood region, reinforcing their regulatory role associated with secondary wall development. ClMYB1 was experimentally proven a transcriptional activator that localised in the nucleus. The overexpression of ClMYB1 in Nicotiana benthamiana resulted in an increased lignin deposition in the stems. The members of subgroup S4, ClMYB3/4/5 shared the ERF-associated amphiphilic repression motif with AtMYB4, which is known to repress the metabolism of phenylpropanoid derived compounds. They also carried a core motif specific to gymnosperm lineage, suggesting divergence of the regulatory process compared to the angiosperms. Conclusions This work will enrich the collection of full-length gymnosperm-specific R2R3-MYBs related to stem development and contribute to understanding their evolutionary relationship with angiosperm species.

China is one of the diversity centers of gymnosperms. Nearly one-fifth (195 species) of gymnosperms are located in China, but 69 species are threatened. To date, the conservation status of gymnosperms, especially threatened gymnosperms in China, remains largely unknown, which seriously restricts the comprehensive protection of gymnosperms. Understanding the distribution pattern of species richness and exploring the relationships between species richness and environmental factors are key steps for their protection. In this study, we first constructed a database for the 69 threatened species of gymnosperms with 13 270 distribution records. It is found that 31 of the grid cells (50 × 50 km) cover all threatened gymnosperm species in China, and the grid cells of threatened gymnosperms are mainly distributed in the southern area of the Yellow River, with a distribution center in the Western Sichuan Plateau. Then, we evaluated the conservation status of threatened gymnosperms, and the results indicate that 9 (13%) threatened gymnosperms are distributed outside of nature reserves. Therefore, there are still conservation gaps in the protection of threatened gymnosperms in China. We should give more attention to unprotected threatened gymnosperms and conduct taxonomic studies on the species without detailed distribution records. Finally, conservation priority areas and priority conservation levels of threatened gymnosperms in China were proposed. The Western Sichuan Plateau is the most important conservation priority area of threatened gymnosperms. This study will shed light on plant protection and forest management in China.