RESUMO
Cotton has been collected in Brazil for decades for its conservation, evaluation, and the use of its genetic resources. Gossypium mustelinum is an allotetraploid cotton species that only occurs in Brazil, and little is known about its genetic potential for improvement. However, the species is threatened by habitat fragmentation and interspecific hybridization with exotic species of cotton. In this study, we investigated the rate of natural hybridization in two populations of G. mustelinum in Bahia, Brazil, with G. hirsutum and G. barbadense using a set of microsatellite markers.
Assuntos
Gossypium/genética , Hibridização Genética , Alelos , Brasil , Mapeamento Cromossômico , Cromossomos de Plantas , Conservação dos Recursos Naturais , Frequência do Gene , Variação Genética , Genética Populacional , Repetições de Microssatélites , Filogenia , Polimorfismo Genético , TetraploidiaRESUMO
Gene expression related to drought response in the leaf tissues of two Brazilian upland cultivars, the drought-tolerant Douradão and the drought-sensitive Primavera, was analyzed. RNA-seq identified 27,618 transcripts in the Douradão cultivar, with 24,090 (87.2%) homologous to the rice database, and 27,221 transcripts in the Primavera cultivar, with 23,663 (86.9%) homologous to the rice database. Gene-expression analysis between control and water-deficient treatments revealed 493 and 1154 differentially expressed genes in Douradão and Primavera cultivars, respectively. Genes exclusively expressed under drought were identified for Douradão, including two genes of particular interest coding for the protein peroxidase precursor, which is involved in three distinct metabolic pathways. Comparisons between the two drought-exposed cultivars revealed 2314 genes were differentially expressed (978 upregulated, 1336 downregulated in Douradão). Six genes distributed across 4 different transcription factor families (bHLH, MYB, NAC, and WRKY) were identified, all of which were upregulated in Douradão compared to Primavera during drought. Most of the genes identified in Douradão activate metabolic pathways responsible for production of secondary metabolites and genes coding for enzymatically active signaling receptors. Quantitative PCR validation showed that most gene expression was in agreement with computational prediction of these transcripts. The transcripts identified here will define molecular markers for identification of Cis-acting elements to search for allelic variants of these genes through analysis of polymorphic SNPs in GenBank accessions of upland rice, aiming to develop cultivars with the best combination of these alleles, resulting in materials with high yield potential in the event of drought during the reproductive phase.
Assuntos
Adaptação Fisiológica/genética , Secas , Ecótipo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Oryza/genética , Oryza/fisiologia , Clima Tropical , Sequência de Bases , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Ontologia Genética , Redes e Vias Metabólicas/genética , Anotação de Sequência Molecular , Folhas de Planta/genética , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/genéticaRESUMO
Drought and rice blast disease caused by Magnaporthe oryzae are two of the most serious threats to global rice production. To explore the mechanisms underlying gene expression induced in rice by stresses, studies involving transcriptome analyses have been conducted over the past few years. Thus, it is crucial to have a reliable set of reference genes to normalize the expression levels of rice genes affected by different stresses. To identify potential reference genes for studies of the differential expression of target genes in rice under M. oryzae infection and drought conditions, the present study evaluated five housekeeping genes for the normalization of gene expression. The stability of the expression of these genes was assessed using the analytical software packages geNorm and NormFinder. For all samples analyzed, the stability rank was UBQ5 > GAPDH > eIF-4α> ß-TUB > 18S rRNA. The data showed that the UBQ5, GAPDH, and eIF-4αgenes are appropriate, high-performing reference genes and will be highly useful in future expression studies of fungal infections and drought in rice.
Assuntos
Regulação da Expressão Gênica de Plantas , Genes Essenciais , Genes de Plantas , Oryza/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Secas , Fator de Iniciação 4A em Eucariotos/genética , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/genética , Magnaporthe/patogenicidade , Magnaporthe/fisiologia , Oryza/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Padrões de Referência , Estresse Fisiológico , Transcriptoma , Ubiquitina/genéticaRESUMO
The Cecropia spp. (Cecropiaceae) trees are attacked by several insects; among them, Coelomera lanio (Dalman) (Coleoptera: Chrysomelidae). The reproductive behavior of C. lanio was studied under laboratory conditions (12 hour photoperiod, 24.1 +/- 0.1 degrees C and mean relative humidity 67.7 +/- 0.6%), in Viçosa, Minas Gerais, Brazil. The insects were reared in cages and in Petri dishes and fed leaves of Cecropia pachystachya Trec. Reproductive activity began 5.8 +/- 0.2 days after adult emergence and mean copulation time was 2.5 +/- 0.1 min. The female began oviposition only after 25.7 +/- 0.7 days. Each female laid a mean of 4.7 +/- 0.4 times (range 1-9). The mean number of eggs per oviposition and female was 129.2 +/- 2.4 and 587.4 +/- 92.1 respectively, and the time between egg-layings averaged 16.3 +/- 0.8 days.
