MicroRNAs Associated with Secondary Metabolites Production

MicroRNAs (miRNAs) are noncoding RNAs that play an important role in the regulation of the genetic expression in animals and plants by targeting mRNAs for cleavage or translational repression. Several miRNAs regulate the plant development, the metabolism, and the responses to biotic and abiotic stresses. Characterization of an miRNA has helped to show its role in fine tuning the mechanisms of posttranscriptional gene regulation. Although there is a lot of information related to miRNA regulation of some processes, the role of miRNA involved in the regulation of biosynthesis of secondary plant product is still poorly understood. In this chapter, we summarize the identification and characterization of miRNAs that participate in the regulation of the biosynthesis of secondary metabolites in plants and their use in the strategies to manipulate a controlled manipulation

Tissue-specific transcriptional biomarkers in medicinal plants: Application of large-scale meta-analysis and computational systems biology

© 2019 Elsevier BV. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (January 2019) in accordance with the publisher’s archiving policyBiosynthesis of secondary metabolites in plant is a complex process, regulated by many genes and influenced by several factors. In recent years, the next-generation sequencing (NGS) technology and advanced statistical analysis such as meta-analysis and computational systems biology have provided novel opportunities to overcome biological complexity. Here, we performed a meta-analysis on publicly available transcriptome datasets of twelve economically significant medicinal plants to identify differentially expressed genes (DEGs) between shoot and root tissues and to find the key molecular features which may be effective in the biosynthesis of secondary metabolites. Meta-analysis identified a total of 880 genes with differential expression between two tissues. Functional enrichment and KEGG pathway analysis indicated that the functions of those DEGs are highly associated with the developmental process, starch metabolic process, response to stimulus, porphyrin and chlorophyll metabolism, biosynthesis of secondary metabolites and phenylalanine metabolism. In addition, systems biology analysis of the DEGs was applied to find protein–protein interaction network and discovery of significant modules. The detected modules were associated with hormone signal transduction, transcription repressor activity, response to light stimulus and epigenetic processes. Finally, analysis was extended to search for putative miRNAs that are associated with DEGs. A total of 31 miRNAs were detected which belonged to 16 conserved families. The present study provides a comprehensive view to better understand the tissue-specific expression of genes and mechanisms involved in secondary metabolites synthesis and may provide candidate genes for future researches to improve yield of secondary metabolites

Acúmulo de biomassa, produção de esteviosídeo e rebaudiosídeo A e tolerância à geada e ao acamamento de acessos de Stevia rebaudiana Bert.

Orientador : Prof. Dr. Cícero DeschampsDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Programa de Pós-Graduação em Agronomia. Defesa: Curitiba, 24/02/2015Inclui referênciasÁrea de concentração: Produção vegetalResumo: Stevia rebaudiana Bert. é uma espécie da família Asteraceae, herbácea, nativa do Brasil e Paraguai e economicamente importante devido à aplicação como adoçante não calórico. O poder adoçante advém da produção dos glicosídeos diterpênicos esteviosídeo (EST) e rebaudiosídeo A (RA) que são, respectivamente, 300 e 450 vezes mais doces que a sacarose e não são calóricos por não serem absorvidos no trato intestinal humano. A estévia também possui propriedades medicinais como anti-hiperglicêmica, anti-hipertensiva, anti-inflamatória, antitumoral e antioxidante. No Brasil, o cultivo de estévia é incipiente e não há produção suficiente para atender a demanda do mercado interno. No ano de 2013, o Brasil importou acima de US$8 milhões e exportou US$ 2,7 milhões de estévia. Para o avanço do cultivo no Brasil, há carência de materiais genéticos com padrão industrial adaptados às condições edafoclimáticas de cada região produtora. O objetivo deste trabalho foi avaliar o acúmulo de biomassa, produção de EST e RA e tolerância à geada e ao acamamento de sete acessos de estévia nas condições climáticas da região metropolitana de Curitiba, PR. O plantio foi realizado na última semana de outubro de 2013 com espaçamento 25x50 cm, resultando em população de 80.000 plantas ha-1. A produtividade de massa seca de folhas, índice de área foliar, área foliar específica, teores de EST e RA por HPLC, relação entre RA/EST, produtividade de EST e RA, tolerância à geada e ao acamamento e morfologia dos acessos foram avaliados. Os acessos 6, 7 e 14 apresentaram padrão químico exigido pela indústria com relação RA/EST próxima ou superior a 1 e produtividade de até 558,5 kg ha-1 de EST e 553,1 kg ha-1 de RA. Os acessos com maior altura e menores ramificação, índice de área foliar e área foliar específica são superiores em RA e relação RA/EST. Os acessos 4, 7 e 8 são os mais tolerantes à geada e os acessos 7 e 14 mais suscetíveis ao acamamento. Palavras-chave: diabetes, adoçante, estévia, produtividade, morfologia.Abstract: Stevia rebaudiana (Bert.) is an herbaceous species of the family Asteraceae, native in Brazil and Paraguay economically because of its use as a non-caloric sweetener. Its sweetness is a result of the production of diterpene glycosides stevioside (ST) and rebaudioside A (RA), respectively, which are 300 and 450 times sweeter than sucrose and are non-caloric because they are not absorbed in the human intestinal tract. Stevia also has medicinal properties such as anti-hyperglycemic, anti-hypertensive, anti-inflammatory, antitumor and antioxidant. The Brazilian stevia cultivation is incipient and there is no enough production to meet the internal market. In 2013, Brazil imported over U$8 million and exported U$2.7 million of stevia. There is a lack of genetic materials with industry standard and adapted to growing conditions of each producing region. This study aimed to evaluate the potencial production of ST and RA of seven stevia accessions in Cfb climate of Köppen. The planting was in the last week of October 2013 with spacing of 25x50 cm and population of 80,000 plants ha-1. The production of leaf dry matter, leaf area index, specific leaf area, yield of EST and RA, RA/EST ratio, frost tolerance, morphology and lodging of accessions werw evaluated. The accessions 6, 7 and 14 have chemical industrial standard with RA/EST ratio near or over 1 and productivity of 558.5 kg ha-1 of EST and 553.1 kg ha-1 of RA. The accessions high height, low branching, low index of leaf area and low specific leaf area are higher yield RA and ratio RA/EST. The accessions 4, 6, 7 and 8 are tolerant to frost and the accessions 7 and 14 are more susceptible to lodging. Key words: diabetes, sweetener, productivity, morphology

Identification of miR414 and Expression Analysis of Conserved miRNAs from Stevia rebaudiana

MicroRNAs (miRNAs) usually contain 19-24 nucleotides and have been identified as important eukaryotic gene regulators. Applications of various computational approaches have simplified the task by predicting miRNAs from available sequence data sources. In this study, we identified a conserved miR414 from a computational analysis of EST sequence data available from Stevia rebaudiana. In addition, we also identified six conserved miRNAs namely miR169, miR319, miR414, miR164, miR167 and miR398 using stem-loop RT-PCR analysis. Hence, miR414 was commonly identified using both methods. The expression analysis of these miRNAs documented their roles in growth and development of Stevia. Furthermore, the detected miRNAs were found to target genes involved in plant growth, development, metabolism and signal transduction. This is the first study reporting these conserved miRNAs and their expression in Stevia