No description available.

Made available in DSpace on 2014-06-11T19:28:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-19Bitstream added on 2014-06-13T20:58:16Z : No. of bitstreams: 1 vasconcelos_rt_me_jabo.pdf: 229680 bytes, checksum: e9ad586e99b84a5606b13d8fbf2bad77 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi determinar a necessidade e a concentração apropriada de ácido indolbutírico (AIB) no enraizamento de estacas de K. senegalensis A.Juss. para a produção de mudas. O material vegetal foi constituído de 540 estacas caulinares de mudas jovens de origem seminal. As bases das estacas foram tratadas pelo método de imersão lenta em solução de etanol a 5% durante 12 h contendo 0, 100, 200, 400 mg L-1 de AIB e via imersão rápida em solução de etanol a 50% durante cinco segundos contendo 0, 3000, 6000, 9000 e 12000 mg L-1 de AIB. O delineamento experimental foi o inteiramente casualizado com um total de nove tratamentos, cinco repetições e 12 estacas por parcela. As estacas permaneceram em bandejas contendo vermiculita por 45 dias e, após este período, foi avaliado a porcentagem de sobrevivência das estacas, porcentagem de estacas enraizadas, número de raízes adventícias por estaca e comprimento total de raízes adventícias por estaca. Após essas avaliações, as estacas que enraizaram foram transferidas para vasos de plástico contendo 1500 cm3 de substrato à base de casca de pinus, sendo mantidas por 120 dias adicionais, para avaliação da porcentagem de sobrevivência das mudas, porcentagem de plantas com brotações e altura das brotações. A produção de mudas de Khaya senegalensis pode ser obtida pela estaquia de ramos provenientes de mudas de origem seminal, sem o uso de AIB / This work aim was stablish the requirement as well the appropriated concentration of Indolbutiric Acid (IBA) in the Khaya senegalensis A.Juss. stem cuttings to produce new plants. The vegetal material consisted of 540 seed-origin young stem cuttings. The cuttings base were treated via 5% ethanol solution slow-immersion method during 12h with 0, 100, 200, and 400 mg L-1 of IBA and via 50% ethanol solution fast-immersion method during 5 seconds with 0, 3000, 6000, 9000, and 1200 mg L-1 of IBA. The experimental design used was the completely randomized with nine treatments, five replications and twelve cuttings per plot. The cuttings were in trays containing vermiculite per 45 days and then the cutting surviving percentage, cutting rooting percentage, adventitious roots number per cutting, and total adventitious roots length per cutting were evaluated. Later, the rooted cuttings were transferred to plastic pots containing 1500 cm3 of pine-based substrate, staying in it 120 days to evaluate the new plants surviving percentage, budding percentage, and budding height. The production of new plants of Khaya senegalensis can be obtained by cutting branches from seedlings, without IBA use

Orientador: Sérgio Valiengo Valeri / Banca: Vitor Corrêa de Mattos Barretto / Banca: Antonio Baldo Geraldo Martins / Resumo: O objetivo deste trabalho foi determinar a necessidade e a concentração apropriada de ácido indolbutírico (AIB) no enraizamento de estacas de K. senegalensis A.Juss. para a produção de mudas. O material vegetal foi constituído de 540 estacas caulinares de mudas jovens de origem seminal. As bases das estacas foram tratadas pelo método de imersão lenta em solução de etanol a 5% durante 12 h contendo 0, 100, 200, 400 mg L-1 de AIB e via imersão rápida em solução de etanol a 50% durante cinco segundos contendo 0, 3000, 6000, 9000 e 12000 mg L-1 de AIB. O delineamento experimental foi o inteiramente casualizado com um total de nove tratamentos, cinco repetições e 12 estacas por parcela. As estacas permaneceram em bandejas contendo vermiculita por 45 dias e, após este período, foi avaliado a porcentagem de sobrevivência das estacas, porcentagem de estacas enraizadas, número de raízes adventícias por estaca e comprimento total de raízes adventícias por estaca. Após essas avaliações, as estacas que enraizaram foram transferidas para vasos de plástico contendo 1500 cm3 de substrato à base de casca de pinus, sendo mantidas por 120 dias adicionais, para avaliação da porcentagem de sobrevivência das mudas, porcentagem de plantas com brotações e altura das brotações. A produção de mudas de Khaya senegalensis pode ser obtida pela estaquia de ramos provenientes de mudas de origem seminal, sem o uso de AIB / Abstract: This work aim was stablish the requirement as well the appropriated concentration of Indolbutiric Acid (IBA) in the Khaya senegalensis A.Juss. stem cuttings to produce new plants. The vegetal material consisted of 540 seed-origin young stem cuttings. The cuttings base were treated via 5% ethanol solution slow-immersion method during 12h with 0, 100, 200, and 400 mg L-1 of IBA and via 50% ethanol solution fast-immersion method during 5 seconds with 0, 3000, 6000, 9000, and 1200 mg L-1 of IBA. The experimental design used was the completely randomized with nine treatments, five replications and twelve cuttings per plot. The cuttings were in trays containing vermiculite per 45 days and then the cutting surviving percentage, cutting rooting percentage, adventitious roots number per cutting, and total adventitious roots length per cutting were evaluated. Later, the rooted cuttings were transferred to plastic pots containing 1500 cm3 of pine-based substrate, staying in it 120 days to evaluate the new plants surviving percentage, budding percentage, and budding height. The production of new plants of Khaya senegalensis can be obtained by cutting branches from seedlings, without IBA use / Mestre

Auxin resistant cropping systems will provide producers with an alternative option for weed management, but with this new technology also comes the concern of off target movement of dicamba and/or 2,4-D to susceptible crops. Research was conducted over multiple site years in order to determine the effect of soybean response to different application timings and rates of 2,4-D and dicamba. 2,4-D was applied at 1X (0.56 kg ae/ha), 1/4X, 1/16X, 1/64X, and 1/256X rates, and dicamba was applied in a separate study at 1X (0.56 kg ae/ha), 1/4X, 1/16X, 1/64X, 1/256 and 1/1024X. All rates were applied at the V3 and R1 growth stages. Greatest yield losses occurred from dicamba applied at the R1 growth stage. Additional studies were conducted to determine at which growth stage soybeans are most sensitive to 2,4-D and dicamba. Greatest yield losses occurred at the late vegetative and early reproductive growth stages for both herbicides.

No description available.

No description available.

Proteomics is defined as a tool to explore how proteins control and regulate important molecular and physiological processes. Further, peptide-centric approaches, or bottom-up methods, provide more comprehensive coverage of a proteome compared to whole-protein approaches. This body of work assesses the technical feasibility of several bottom-up proteomics technologies applied to Arabidopsis thaliana, including gel-based methods, those that require peptide derivitization, and those that do not. Selected-reaction monitoring (SRM) for targeted proteomics, and data-independent acquisition (MSE) was also evaluated. In addition to assessing the capabilities of these technologies, we then applied them to the context of uncovering new insights into the flavonoid biosynthetic pathway and the auxin and ethylene signaling pathways. Chapter one provides background information related to secondary metabolism, phytohormone signaling, and the status of proteomics in plants. In Chapter 2 and Appendix A, we establish the methodology to apply traditional and DiGE-based 2D-GE strategies to global proteomics in Arabidopsis. Our results suggest that while 2D-GE is applicable to Arabidopsis, there are practical and conceptual limitations that must be understood. Further, our results suggest that pertubations in the flavonoid pathway do not affect the abundance of proteins in Arabidopsis seedlings, roots, or flowers that can be studied using 2D-GE and DiGE. Additionally, we demonstrated the first parallel comparison of the effects of auxin and ethylene on the Arabidopsis root proteome and observed no overlap among the proteins regulated by the two phytohormones, at least for the most abundant proteins observed by 2D-GE. Chapter 3 explores the efficacy of selected reaction monitoring for relative peptide quantification in Arabidopsis roots. Our results suggest that while the technology parallels application in yeast and humans, there are substantial analytical challenges that much be addressed. In Chapter 4 we explore the MSE data acquisition scheme for global proteomics in Arabidopsis. We observe that treatment with exogenous auxin affects the abundance of many proteins representing diverse biological processes. Interestingly, we observe minimal overlap among genes and proteins regulated by exogenous auxin. Appendix B explores the efficacy of iTRAQ labeling for relative peptide quantification in Arabidopsis roots. / Ph. D.

The plant hormones gibberellins (GAs) regulate multiple processes of plant development. Most of this regulation occurs at the transcriptional level, through the activity of the DELLAs, which are nuclear-localized proteins subjected to GA-mediated proteolitic degradation. DELLAs are encoded by five genes, and genetic studies show that each DELLA displays specific, but also partially overlapping roles with respect to their paralogs. In this Thesis, we have addressed two issues: (1) the contribution of DELLA multiplication to the diversification of functions controlled by GAs; and (2) the identification of direct targets regulated by DELLAs in etiolated seedlings with special attention to those involved in differential growth processes. Using combinations of mutants and transgenic lines expressing two phylogenetically distant DELLA genes (RGA and RGL2), we have found that these two DELLA proteins can perform each other's role as long as they are expressed under the reciprocal promoters, indicating that DELLA subfunctionalization relies mainly on their differential expression patterns. To identify direct DELLA targets, we have performed transcriptomic analyses of dark-grown seedlings expressing an inducible version of gai-1, a stable, dominant allele of a DELLA gene. This approach rendered a list of over 150 genes differentially expressed after induction of gai-1. The presence of several auxin-related genes among the primary targets of DELLA proteins has allowed us to establish a new role for GAs in the modulation of hypocotyl gravitropism through the repression of IAA19/MASSUGU2 expression by DELLAs. Moreover, the repression of HOOKLESS1 and the auxin efflux carriers PIN3 and PIN7 by DELLAs, is proposed as the molecular mechanism to explain the already known physiological regulation of apical hook development by GAs. / Gallego Bartolomé, J. (2011). Della protein function during differential growth processes in arabidopsis [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/11403

The morphology of plant body is shaped by genetically coded developmental programme together with environmental factors. The influence of environmental factors on the morphology is much more important in plants that in other multicellular organisms. The developmental programme provides a general scheme that is modified by environmental signals. Phytohormone auxin is a regulator of plant morphogenesis and its distribution in the plant body is an important mechanism controling the growth and development of plants and coordinating the developmental programme with environmentally-induced changes. This thesis investigates factors important for transport of auxin from cells, second part is dedicated to bioinformatic analysis of the transporters from the PIN protein family. For investigation of signals involved in regulation of activity of auxin efflux transporters I have selected (based on published information) physiological signals influencing auxin transport. These signals were changed by treatment with chemicals and resulting changes in auxin transport were measured (on the cellular level) with the intention to discover signals that can rapidly (within minutes) change the activity of auxin efflux transporters. The signals, which satisfy these requirements were subjected to further investigation. He detailed...

The differentiation of plant vascular tissue is regulated by plant hormones and transcription factors. One of the key plant hormones involved in this process is auxin. Auxin signals are mediated by auxin response factor transcription factors (ARFs). These transcription factors are involved in the perception of auxin signals and the subsequent activation or deactivation of suites of downstream genes. Based on its mutant phenotype, one of the most interesting members of this family is the ARF MONOPTEROS (MP). This thesis investigates the role played by MP in secondary vascular differentiation, as well as taking a look at other molecular aspects of secondary vascular differentiation, with a focus on the model plants Arabidopsis thaliana and poplar (Populus trichocarpa and hybrid poplar). A dexamethasone inducible RNAi silencing strategy was developed, and transgenic Arabidopsis lines produced. When silencing was induced in these lines from germination, a phenotype closely resembling the mp mutant was observed. When MP silencing was induced in bolting stems, early senescence, as well as a dramatic reduction in interfascicular fibre production was observed, and these stems were thinner and less rigid than empty vector controls. RNA from these stems was isolated and used in a global transcript profiling microarray experiment. This experiment showed that several auxin-related genes, as well as several transcription factors, were differentially regulated in response to MP silencing. Because Arabidopsis is not a typical woody plant, further investigation into the role played by MP in wood formation was done using the model tree poplar. A BLAST search of a poplar xylem EST database identified a single promising partial sequence. Based on this sequence information, a poplar MP homolog was isolated and named PopMP1. The full-length sequence of this gene demonstrated remarkable structural conservation when compared with that of Arabidopsis. Subsequent complete sequencing of the poplar genome revealed a second copy of the MP gene in poplar and named PopMP2. Expression profiling across a range of tissues suggests that subfunctionalization has occurred between the two copies. Overexpression transgenic lines for PoptrMP1 were developed. AtHB8 is known to be regulated by MP in Arabidopsis, and a poplar HB8 homolog was upregulated in the transgenic lines. However, no obvious physical phenotype in these lines was apparent. To investigate the transcriptome-wide changes associated with initiation of cambium formation in poplar stems, a global transcript profiling experiment was performed. Out of 15400 genes tested, 2320 met an arbitrary cutoff of >1.3 fold and p-value <0.05 and were labeled differentially expressed (DE). These included several transcription factors and showed remarkable similarity to analogous data from Arabidopsis. The conclusions drawn from this thesis support the hypothesis that MP plays roles in later development, and do not rule out the possibility that MP is directly involved in wood development. The data reported also offer a large number of candidate for further investigation into the genetic control of wood development.