RESUMO
Gentiana macrophylla, a medicinal plant with significant pharmacological properties, contains the bioactive compound gentiopicroside. Methyl jasmonate (MeJA) is an effective elicitor for enhancing the production of such compounds. However, little is known about MeJA-mediated biosynthesis of gentiopicroside. We investigated this phenomenon as well as gene expression profiles to determine the molecular mechanisms for MeJA-mediated gentiopicroside biosynthesis and regulation in G. macrophylla. Our HPLC results showed that Gentiana macrophylla seedlings exposed to MeJA had significantly higher concentrations of gentiopicroside when compared with control plants. We used RNA sequencing to compare transcriptional profiles in seedlings treated for 5 d with either 0 µmol L-1 MeJA (C) or 250 µmol L-1 MeJA (M5) and detected differentially expressed genes (DEGs). In total, 77,482 unique sequences were obtained from approximately 34 million reads. Of these, 48,466 (57.46%) sequences were annotated based on BLASTs performed against public databases. We identified 5,206 DEGs between the C and M5 samples, including genes related to the α-lenolenic acid degradation pathway, JA signaling pathway, and gentiopicroside biosynthesis. Expression of numerous enzyme genes in the glycolysis pathway was significantly up-regulated. Many genes encoding transcription factors (e.g. ERF, bHLH, MYB, and WRKY) also responded to MeJA elicitation. Rapid acceleration of the glycolysis pathway that supplies precursors for IPP biosynthesis and up-regulates the expression of enzyme genes in that IPP pathway are probably most responsible for MeJA stimulation of gentiopicroside synthesis. Our qRT-PCR results showed that the expression profiles of 12 gentiopicroside biosynthesis genes were consistent with the RNA-Seq data. These results increase our understanding about how the gentiopicroside biosynthesis pathway in G. macrophylla responds to MeJA.
Assuntos
Acetatos/farmacologia , Vias Biossintéticas/genética , Ciclopentanos/farmacologia , Gentiana/genética , Glucosídeos Iridoides/metabolismo , Oxilipinas/farmacologia , Plântula/genética , Transcrição Gênica/efeitos dos fármacos , Vias Biossintéticas/efeitos dos fármacos , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Gentiana/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Anotação de Sequência Molecular , Oxilipinas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Metabolismo Secundário/efeitos dos fármacos , Metabolismo Secundário/genética , Plântula/efeitos dos fármacos , Análise de Sequência de RNA , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Transcriptoma , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Ácido alfa-Linolênico/metabolismoRESUMO
OBJECTIVE: To investigate the influences of temperature, lightness, storage method, storage time, and gibberellin on seed germination of Gentiana rigescens. METHOD: The germination rates of G. rigescens in different treatments were observed. RESULT AND CONCLUSION: The most suitable temperature for the seed germination was 25 degrees C, at which the germination rate was 76.33%. The effect of lightness on the seeds was significantly; the germination rate of the seed was very low. Under the natural condition, the best storage method was dry storage (within 6 months), which could promote the after-ripening of the seed. 100-1 000 mg x L(-1) gibberellic acid could significantly reduce the seed germination time, and 500 mg x L(-1) gibberellic acid increased the germination rate of the seed to 95.00%.