In Europe, fossil fruits and seeds of Rhodoleia (Hamamelidaceae) have been described from the Upper Cretaceous to the Miocene, whereas no fossil record of Rhodoleia has been reported in Asia, where the modern species occur. Herein, 21 fossil leaves identified as Rhodoleia tengchongensis sp. nov. are described from the Upper Pliocene of Tengchong County, Yunnan Province, Southwest China. The fossils exhibit elliptic lamina with entire margins, simple brochidodromous major secondary veins, mixed percurrent intercostal tertiary veins, and looped exterior tertiaries. The leaf cuticle is characterized by pentagonal or hexagonal cells, stellate multicellular trichomes, and paracytic stomata. The combination of leaf architecture and cuticular characteristics suggests that the fossil leaves should be classified into the genus Rhodoleia. The fossil distributions indicate that the genus Rhodoleia might originate from Central Europe, and that migrated to Asia prior to the Late Pliocene. Additionally, insect damage is investigated, and different types of damage, such as hole feeding, margin feeding, surface feeding, and galling, are observed on the thirteen fossil leaves. Based on the damage frequencies for the fossil and extant leaves, the specific feeding behavior of insects on Rhodoleia trees appears to have been established as early as the Late Pliocene. The high occurrence of Rhodoleia insect herbivory may attract the insect-foraging birds, thereby increasing the probability of pollination.

Twenty-one fossil foliage, identified as Fokienia shengxianensis sp. nov. (Cupressaceae), were collected from the upper Miocene Shengxian Formation in Tiantai and Ninghai counties, Zhejiang Province of eastern China. These fossils can likely be distinguished from other extant genera in the family Cupressaceae s.l. except Fokienia by leaf external morphology alone. Foliar cuticular comparison with the only modern species in this genus, Fokienia hodginsii Henry et Thomas, further suggests that the present fossil species closely resembles the modern counterpart. Paleoecologically, the occurrence of Fokienia from the Shengxian Formation appears to support that the fossil site was covered by subtropical evergreen broad-leaved forest and under warm and humid conditions during the late Miocene, consistent with evidence from previously published fossil plants.

Eight fossil leaves identified as Exbucklandia tengchongensis sp. nov. (Hamamelidaceae) were collected from the Pliocene Mangbang Formation in Tengchong, Yunnan Province, Southwest China. The fossil leaves are characterized by the overall rounded lamina with entire margin, actinodromous venation, and cyclocytic stomata, which suggest the affinity within the genus Exbucklandia, particularly with E. populnea. A survey on the cuticles of the sun and shade leaves of modern E. populnea indicates that the shade leaves generally possess more pronounced undulate anticlinal cell walls and a much lower stomatal density than the sun leaves. Two morphotypes, i.e. sun vs. shade types, of the fossil leaves were therefore recognized. The distribution of the modern Exbucklandia suggests that the genus lives under a warm climate with a mean annual temperature (MAT) from 13 °C to 27 °C and a mean annual precipitation (MAP) from 800 mm to 2500 mm. Hence, E. tengchongensis might also live under a similar climatic condition in the Pliocene. Leaf margin analysis on the Tengchong flora supports this result. The little change of Neogene MAT in Southwest China is therefore supported.

No description available.

No / Background Hair is degraded by the action of both dermatophytic and nondermatophytic microorganisms. The importance of understanding hair sample condition in archaeological and forensic investigation highlights the need for a detailed knowledge of the sequence of degradation in samples that have been either buried or left exposed at the ground surface. Objectives To investigate the sequence of biodegradative change to human terminal scalp hair from archaeological and forensic contexts. Methods Cut modern scalp hair from three individuals with caucasoid-type hair was inoculated with soil microorganisms through soil burial in the field and under laboratory conditions to produce experimentally degraded samples. The degraded hair fibres were subjected to detailed histological examination using a combination of high-resolution light microscopy, transmission electron microscopy and scanning electron microscopy to investigate the nature and sequence of degradative change to hair structural components. Results/discussion Degradation was found to occur first within the least structurally robust components that afford the least resistance to microbial/chemical attack. The sequence of degradation (most to least-reflecting degree of vulnerability) in the hair cuticle was as follows: (1) intercellular 6-layer (cell membrane complex); (2) endocuticle; (3) cell membrane ß-layers; (4) exocuticle; (5) epicuticle; and (6) A-layer. In the hair cortex this was as follows: (I) intercellular 6-layer (cell membrane complex); (II) cell membrane ß-layers; (III) intermacrofibrillar matrix/nuclear remnants; (IV) microfibrils; (V) intermicrofibrillar matrix; and (VI) pigment granules (the hair fibre component that was the least vulnerable to degradation). Conclusions The selective progress of degradation in the hair shaft has been charted and this provides a basis for further histological work in better understanding the condition of hair fibres derived from archaeological or forensic contexts as well as being relevant to investigation of diseased hair, in particular hair infected by dermatophytes and hair weakened by genetic hair shaft abnormalities.

The occurrence of winter injury in red spruce (<u>Picea rubens</u>) L. sarg. and Fraser fir (<u>Abies fraseri</u>) pursh. poir. in relation to the level of atmospheric nitrates and climatic parameters of precipitation and temperatures was investigated. Data and foliage samples were collected from established field plots at 5500, 6000, and 6500 feet in the Black Mountains of North Carolina and from seedlings under 4 treatments of artificial rainfall. varying by N03 concentration. Samples were collected 4 times over the 1987 growing season. Responses were similar in shadehouse and field samples. Wax content differed between collections but not between treatment levels. except for shadehouse spruce. and wax content decreased after collection 2. Between treatment levels. differences were found in the amount of water lost over 14 hours, but not in the average initial fresh weight dry weight ratio (RWT). Differences were found in both RWT and transpiration rate over the growing season with field trees decreasing or remaining stable with each collection. and shadehouse seedlings increasing. No relationship between climatic parameters and annual leader growth was modeled because understory field trees were immature and exhibiting height growth. masking the effects of climate to understory trees. Winter injury ratings decreased from summer of 1987 to spring of 1988 and no significant differences in ratings were found between elevations. Classic winter injury symptoms were observed on one plot at 6500 feet, but most ratings greater than 0 were given because of the effects of shading from the overstory. / Master of Science

The conserved metabolites, oleic acid (18:1), a major monounsaturated fatty acid (FA), and glycerol-3-phosphate (G3P) are obligatory precursors of glycerolipid biosynthesis in plants. In Arabidopsis, the SSI2-encoded SACPD is the major isoform that contributes to 18:1 biosynthesis. Signaling induced upon reduction in oleic acid (18:1) levels not only upregulates salicylic acid (SA)-mediated responses but also inhibits jasmonic acid (JA)- inducible defenses. I examined the transcription profile of ssi2 plants and identified two transcription factors, WRKY50 and WRKY51. Although the ssi2 wrky50 and ssi2 wrky51 plants were constitutively upregulated in SA-derived signaling, they were restored in JAdependent defense signaling. Not only did these plants show JA-inducible PDF1.2 expression, but they were also restored for basal resistance to the necrotrophic pathogen, Botrytis cinerea. Overall, my results show that the WRKY50 and WRKY51 proteins mediate both SA- and low 18:1-dependent repression of JA signaling in Arabidopsis plants. My studies also show that cellular G3P levels are important for plant defense to necrotrophic pathogens. I showed that G3P levels are induced in Arabidopsis in response to the necrotrophic fungal pathogen B. cinerea. G3P-dependant induction of basal defense is not via the activities of other defense-related hormones such as SA, JA or the phytoalexin camalexin. Arabidopsis mutants unable to accumulate G3P (gly1, gli1) showed enhanced susceptibility to B. cinerea. Previous studies in our lab identified acyl-carrier protein 4 (ACP4), a component of FA and lipid biosynthesis, as an important regulator of plant systemic immunity. ACP4 mutant plants were defective in systemic acquired resistance (SAR) because they contained a defective cuticle. I further investigated the role of the plant cuticle in SAR by studying the involvement of long-chain acyl-CoA synthetases (LACS), a gene family involved in long-chain FA and cuticle biosynthesis, in SAR. In all, eight lacs mutants (lacs1, lacs2, lacs3, lacs4, lacs6, lacs7, lacs8, lacs9) were isolated and characterized. Six mutants were compromised in SAR. Together, my studies show that the various LACS isoforms contribute differentially to both cuticle formation and systemic immunity in Arabidopsis.

La cuticule, une matrice lipidique extracellulaire constituée de cires et d’un squelette de cutine, est la barrière de défense la plus externe des plantes face à leur environnement. Elle intervient dans de nombreuses propriétés agronomiques comme la conservation post récolte, les propriétés mécaniques ou bien l’aspect du fruit, dont la brillance. Afin d’isoler des mutants de cuticule, le criblage d’une collection de mutants EMS de tomate a été entrepris, en se basant sur la brillance des fruits, conduisant à la sélection de 24 mutants. Chez ceux-ci, des analyses biochimiques ont montré de fortes variations de charge et de composition de la cuticule, notamment chez les mutants de cutine. La caractérisation de 4 mutants remarquables a été entreprise afin d’identifier les mutations responsables des phénotypes de brillance. Le mutant le plus affecté, présentant une charge en cutine réduite de 85% par rapport au type sauvage, a révélé une mutation du gène SlGDSL2 codant pour une acylhydrolase à motif GDSL, responsable de la polymérisation de la cutine. Afin d’étudier la formation et la régulation de la cutine, la suite du travail a consisté à obtenir et à caractériser des simples et des doubles mutants affectés dans la synthèse des monomères de cutine, le transport apoplastique et la polymérisation de la cutine. / The cuticle, an extracellular lipid matrix consisting of waxes and of a cutin skeleton is the outermost plants protection barrier against their environment. The cuticle is involved in many agronomic traits such as post-harvest storage, biomechanical or fruit appearance properties like surface brightness. In order to isolate cuticle mutants, the screening of an EMS tomato mutants collection has been undertaken, based on fruit brightness, leading to the selection of 24 mutants. Biochemical analyzes have shown wide variations in cuticle loads and compositions, especially in cutin mutants. The characterization of 4 remarkable mutants was undertaken to identify the mutations responsible for brightness phenotypes. The most affected mutant shows a cutin load reduced by 85% compared to the wild type, and is due to a mutation in the SlGDSL2 gene, encoding a GDSL-motive acylhydrolase enzyme, responsible for the cutin polymerization. In order to further study the cutin formation and regulation, the next work was to obtain and characterize single and double mutants affected in cutin monomer synthesis, apoplastic transport and cutin polymerization.

Master of Science / Department of Biology / Loretta Johnson / Plant epicuticular wax (ECW) isolates internal tissues from harsh external conditions increasing drought tolerance. Beta-diketone-rich ECW reflect light and result in a glaucous phenotype that may ameliorate the thermal environment of the leaf. The overall goal is to characterize the form and function of ECW in two closely related, but phenotypically divergent grasses. [italicized]Andropogon gerardii ssp. [italicized]gerardii, big bluestem, is a non-glaucous, agronomically and ecologically dominant grass in the United States while [italicized]Andropogon gerardii ssp. [italicized]hallii, sand bluestem, is a glaucous subspecies restricted to dry, sandy soils. The objectives are to contrast sand and big bluestem ECW chemistry, morphology, and physiology to determine the distinctions in ECW resulting in the glaucous phenotype and determine the effect this has on leaf optical qualities and permeability. Gas chromatography mass spectrometry (GC-MS) and scanning electron microscopy (SEM) were used to examine ECW chemistry and micromorphology. It was hypothesized that beta-diketones and beta-diketone tubules where present only in leaves of sand bluestem and that the ECW was more reflective and abundant and the cuticle was less permeable. Beta-diketones and tubular ECW were absent in big bluestem and common on sand bluestem’s surface, although less than 20% of ECW was beta-diketones. Functional implications of ECW phenotypes were investigated by comparing minimum conductance (G[subscript]min), wax load, reflectance, and transmittance. Reflectance, with and without ECW, and G [subscript]min were measured with an infrared gas analyzer and a spectroradiometer, respectively. Sand bluestem had twice the ECW in mg cm[superscript]2 (P=.01) and three times lower G [subscript]min in ms[superscript]-1 10[superscript]-5 (P=.02). Partial least squares (PLS) models were trained to predict subspecies from reflectance spectra and were able to distinguish the subspecies. These experiments indicate that in comparison to big bluestem, increased reflectance is a property uniquely imparted to sand bluestem by ECW and the presence of beta-diketones determines the distinction. Glaucous crop species have shown higher yield under drought and extreme weather, including drought, is expected to become more common. Therefore, this study of glaucous waxes, may be applied in engineering drought tolerance.

Como qualquer inseto holometábolo, a abelha Apis mellifera sofre metamorfose completa, apresentando grandes mudanças na forma e fisiologia quando passa do estágio larval para o estágio de pupa (muda metamórfica). Após esta muda, com o prosseguimento do desenvolvimento, o tegumento pupal (cutícula e a epiderme subjacente), extensivamente remodelado, é substituído pelo tegumento adulto, definitivo, que passa por intensa melanização e esclerotização. Eletroforese bidimensional e espectrometria de massas foram utilizadas neste trabalho para caracterizar as mudanças do padrão proteico no tegumento em desenvolvimento de operárias e zangões. No total foram identificadas 51 proteínas diferentes no tegumento torácico extraído de larvas, pupas e adultos (adultos-faratos). Quatorze proteínas foram identificadas como genuinamente cuticulares: Apidermina-3,1-like, Apidermina-2, Cuticular proteins analogous to peritrophins-3C e 3D, AmelCPR3, 12, 16 e 27, Glicoproteína SgAbd-2-like, e cinco outras proteínas homólogas à proteínas cuticulares de outras espécies de insetos contendo um domínio de ligação à quitina. As proteínas diferiram principalmente quantitativamente entre as fases de desenvolvimento e sexo, e poucas diferenças qualitativas foram observadas. Por exemplo, Apidermina-2 é típica de tegumentos fortemente esclerotizados e pigmentados. As diferenças quantitativas foram destacadas pela comparação da abundância de algumas proteínas e seus respectivos RNA mensageiros (utilizando RT-PCR em tempo real) entre as fases de desenvolvimento e entre os sexos. Várias proteínas cuticulares mostraram mais de uma forma molecular, aparentemente derivadas de modificações pós-traducionais. Além de conferir suporte experimental para a validação de genes de A. mellifera preditos, ou não-anotados, nossos dados forneceram novas informações sobre as proteínas que atuam no tegumento em desenvolvimento. / As a holometabolous insect, the honey bee undergoes complete metamorphosis, displaying a marked change in shape and physiology when passing from the larval to the pupal stage (metamorphic molt). As development progresses, the extensively remodeled pupal integument (cuticle and subjacent epidermis) is replaced by the adult integument, which undergoes intense sclerotization and melanization. Two-dimensional electrophoresis and mass spectrometry were here used to characterize the changing protein patterns in the developing integument of workers and drones. Overall, we identified 51 different proteins in the thoracic integument extracted from larvae, pupae and adults (pharate adults). Fourteen proteins were identified as genuine cuticular proteins: Apidermin-3,1-like protein, Apidermin-2, Cuticular Proteins Analogous to Peritrophins-3C and 3D, AmelCPR3, 12, 16 and 27, Glycoprotein SgAbd-2-like, and 5 other proteins homologous to cuticular proteins from other insect species, and containing the chitin-binding domain. Integument proteins mainly differed quantitatively among the developmental stages and sexes, although few qualitative differences have also been detected. For example, Apidermin-2 is typical of the heavily pigmented and sclerotized integument. The quantitative differences were highlighted by comparing the levels of some of these proteins and their respective mRNAs (using RT-qPCR) among the developmental phases and between sexes. It is noteworthy that several cuticle proteins showed more than one molecular form, apparently derived from post-translational modifications. In addition to give experimental support for validation of predicted, or unannotated, honey bee genes, our data provided new information on proteins acting in the metamorphosing integument.