Ultraviolet –B (UV-B) radiation is an abiotic stress that has significant effects on plant growth, development, and gene regulation. Due to the depletion of the stratospheric ozone layer over the past several decades, the amount of UV-B light that is reaching the earth’s surface has significantly increased. As a result, research over the past few decades on the effects of UV-B light on plant growth, development, and the mechanisms that regulate a plant’s protection and survival against UV-B light has grown greatly. Brachypodium distachyon is a relatively new model system and one that has not been extensively studied. The aim of this study was to determine the UV-B dose time required to elicit a significant increase in phenolic content, while subsequently assessing protein production to qualitatively implicate whether or not the experimental dosage of UV-B administered was initiating a UV-B specific or non-specific response. In addition, this research annotated the genes that encode the protein sequences for UVR8 and CHS proteins to see if B. distachyon possessed the necessary proteins to undergo a UV-B specific response similar to that of Arabidopsis. The results of the study show that in response to artificial UV-B light, the dose time of UV-B required to elicit a significant increase in total phenolic content is 2 hours. The data also shows an increase in total protein content after 4 hours of UV-B exposure. In addition to the metabolic data, computational analysis of chalcone synthase (CHS) and UV-RESISTANCE LOCUS 8 (UVR8) revealed that there are seven genes in B. distachyon that encode the protein transcripts for CHS and CHS-like proteins, and two genes that code for UVR8 proteins. The results of this study suggest that the UV-B dose regimen used in this study may be initiating the non-specific UV-B signaling pathway. In addition, the presence of UVR8 and CHS protein sequences suggest that B. distachyon has the capacity to work through the UV-B specific signaling pathway.

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Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-11-26T13:31:45Z No. of bitstreams: 2 Dissertação - Samara Rayane Pereira de Morais - 2018.pdf: 1662554 bytes, checksum: a507cd1d13ea851ee565f7b6064db936 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-11-26T13:34:37Z (GMT) No. of bitstreams: 2 Dissertação - Samara Rayane Pereira de Morais - 2018.pdf: 1662554 bytes, checksum: a507cd1d13ea851ee565f7b6064db936 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-11-26T13:34:37Z (GMT). No. of bitstreams: 2 Dissertação - Samara Rayane Pereira de Morais - 2018.pdf: 1662554 bytes, checksum: a507cd1d13ea851ee565f7b6064db936 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-04-17 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The common bean anthracnose caused by the fungus Colletotrichum lindemuthianum is one of the main diseases that impacts negatively on crop yield. The use of resistant cultivars is an efficient tool to control this disease. However, the wide variability of C. lindemuthianum is a challenge for breeding programs. The pyramiding of different resistance alleles is a recommended strategy aiming to effective and durable resistance. Fourteen resistance loci to common bean anthracnose have been identified and described so far: Co-1, Co-2, Co-3, Co-4, Co-5, Co-6, co-8, Co-11, Co- 12, Co-13, Co-14, Co-15, Co16, and Co-17. This work has aimed to: (1) evaluate common bean resistance source based on their reaction to anthracnose in controlled environment and on the molecular analysis with molecular markers previously identified as linked to resistance loci; (2) test the allelic relationship among the anthracnose resistance loci present in the carioca seeded cultivars BRS Horizonte and BRS Cometa; and (3) study the genetic inheritance and mapping the anthracnose resistance in BRS Cometa. The phenotypic screening of the population F2 BRS Horizonte × BRS Cometa and F2 and F2:3 Rosinha G2 × BRS Cometa were carried out using the C. lindemuthianum pathotypes 89 and 91, respectively. The phenotypic and molecular characterization of 26 common bean lines were performed using two pathotypes (races 73 and 81) and seven SCAR and one STS markers. The evaluation of the reaction to disease was carried out using a 1-to-9 scale (resistant = 1 to 3, and susceptible = 4 to 9). The genotyping of the 104 F2 plants from the Rosinha G2 × BRS Cometa cross with SNP markers was carried out using the BARBean6K_3 Illumina Bead Chip on the Illumina Infinium HD Assay Ultra® genotyping platform. The genomic regions flanking the SNP markers were aligned against the reference genome of Phaseolus vulgaris, Andean variety (G19833) and Mesoamerican variety (BAT 93), using the BLASTN tool. As result from the phenotypic characterization, BRS Cometa and other thirteen common bean lines have been considered resistant to the races 73 and 81. The molecular characterization result has indicated that the resistance to anthracnose in BRS Cometa can be controlled by the Co-3 or other resistance locus in the chromosome Pv04, since BRS Cometa has showed amplification only for markers linked to the Co-3. Results from the phenotyping of the F2BRS Horizonte × BRS Cometa population indicated that the segregation ratio for the resistance to anthracnose has fit to the expected ratio of 15R_:1rr ( 2 = 1.24% and P = 26.41%). The segregation ratios in the F2 and F2:3 Rosinha G2 × BRS Cometa population has fit to expected ratio of 3R_:1rr ( 2 = 0.40% and P = 50.50%) and 1RR:2Rr:1rr ( 2 = 0.0% and P = 100%), respectively, indicating that the resistance to anthracnose in BRS Cometa is monogenic and dominant. The anthracnose resistance locus in BRS Cometa (Co-Cometa) was mapped on Pv04. Based on the genetic and physical distances observed between Co-Cometa and other resistance loci already described in Pv04 (Co-3, Co-15 and Co-16), the evidences indicate that Co-Cometa is a different locus. / A antracnose do feijoeiro, causada pelo fungo Colletotrichum lindemuthianum, é uma das principais doenças que impacta negativamente a produtividade da cultura. Para o manejo dessa doença, a utilização de cultivares resistentes é uma ferramenta eficiente. Porém, a ampla variabilidade de C. lindemuthianum representa um desafio para os programas de melhoramento genético. Deste modo, a piramidação de distintos alelos de resistência é uma estratégia recomendada. Atualmente, 14 locos de resistência à antracnose já foramcaracterizados e descritos: Co-1, Co-2, Co-3, Co-4, Co-5, Co-6, co-8, Co-11, Co-12, Co13, Co-14, Co-15, Co-16 e Co-17. O presente trabalho teve como objetivos: 1) avaliar linhagens fontes de resistência com base na reação à antracnose em ambiente controlado e análise molecular com marcadores moleculares identificados como ligados a locos de resistência; 2) testar a relação alélica entre os locos de resistência à antracnose presentes nas cultivares de feijão carioca BRS Horizonte e BRS Cometa; e 3) estudar a herança e mapear a resistência à antracnose na cultivar BRS Cometa. Foi realizada a fenotipagem das populações F2 BRS Horizonte × BRS Cometa e F2 e F2:3 Rosinha G2 × BRS Cometa, utilizando as raças 89 e 91, respectivamente. A caracterização fenotípica e molecular de 26 linhagens fontes de resistência foi realizada utilizando dois patótipos (raça 73 e 81) e sete marcadores SCAR e um STS. A avaliação da reação à doença foi realizada utilizando uma escala de notas contendo nove graus de reação (resistentes = 1 a 3 e suscetíveis = 4 a 9). Foi realizada a genotipagem de 104 plantas F2 Rosinha G2 × BRS Cometa com marcadores SNP, utilizando o BARBean6K_3 Illumina Bead Chip na plataforma de genotipagem Illumina Infinium HD Assay Ultra®. As regiões genômicas flanqueando os marcadores SNP foram alinhadas contra o genoma de referência de Phaseolus vulgaris, variedades Andina (G19833) e Mesoamericana (BAT 93), usando a ferramenta BLASTN. Como resultado da caracterização fenotípica, BRS Cometa e 13 linhagens foram consideradas resistentes às raças 73 e 81. A caracterização molecular indicou que a resistência à antracnose presente em BRS Cometa pode ser governada pelo loco Co-3 ou outro loco de resistência presente no cromossomo Pv04, uma vez que BRS Cometa apresentou amplificação apenas para marcadores ligados ao loco Co-3. Os resultados da fenotipagem da população F2 BRS Horizonte × BRS Cometa indicaram que a razão de segregação para resistência à antracnose se ajustou à proporção esperada de 15R_: 1rr ( 2 = 1,24 e P = 26,41%). As razões de segregação nas populações F2 e F2:3 Rosinha G2 × BRS Cometa se ajustaram à proporção esperada de 3R_:1rr ( 2 = 0,40 e P = 50,50%) e 1RR:2Rr:1rr ( 2 = 0,0 e P = 100%), respectivamente, evidenciando que a resistência em BRS Cometa é monogênica dominante. O loco de resistência à antracnose presente em BRS Cometa (CoCometa) foi mapeado no cromossomo Pv04. Com base nas distâncias genéticas e físicas observadas entre Co-Cometa e outros locos de resistência já descritos em Pv04 (Co-3, Co15 e Co-16), as evidencias são que Co-Cometa trata-se de um loco distinto.