RESUMO
The hemibiotrophic fungus Colletotrichum graminicola may cause severe damage to maize, affecting normal development of the plant and decreasing grain yield. In this context, understanding plant defense pathways at the inoculation site and systemically in uninoculated tissues can help in the development of genetic engineering of resistance against this pathogen. Previous work has discussed the molecular basis of maize - C. graminicola interaction. However, many genes involved in defense have not yet been exploited for lack of annotation in public databases. Here, changes in global gene expression were studied in root, male and female inflorescences of maize under local and systemic fungal infection treatments, respectively. RNA-Seq with qPCR was used to indicate genes involved in plant defense. We found that systemic acquired resistance induction in female inflorescences mainly involves accumulation of salicylic acid (SA)-inducible defense genes (ZmNAC, ZmHSF, ZmWRKY, ZmbZIP and PR1) and potential genes involved in chromatin modification. Furthermore, transcripts involved in jasmonic acid (JA) and ethylene (ET) signaling pathways were also accumulated and may participate in plant immunity. Moreover, several genes were functionally re-annotated based on domain signature, indicating novel candidates to be tested in strategies involving gene knockout and overexpression in plants.
Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Transcriptoma/genética , Zea mays/genética , Colletotrichum/genética , Colletotrichum/patogenicidade , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Oxilipinas/metabolismo , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo , Zea mays/microbiologiaRESUMO
Zantedeschia aethiopica is an evergreen perennial plant cultivated worldwide and commonly used for ornamental and medicinal purposes including the treatment of bacterial infections. However, the current understanding of molecular and physiological mechanisms in this plant is limited, in comparison to other non-model plants. In order to improve understanding of the biology of this botanical species, RNA-Seq technology was used for transcriptome assembly and characterization. Following Z. aethiopica spathe tissue RNA extraction, high-throughput RNA sequencing was performed with the aim of obtaining both abundant and rare transcript data. Functional profiling based on KEGG Orthology (KO) analysis highlighted contigs that were involved predominantly in genetic information (37%) and metabolism (34%) processes. Predicted proteins involved in the plant circadian system, hormone signal transduction, secondary metabolism and basal immunity are described here. In silico screening of the transcriptome data set for antimicrobial peptide (AMP) -encoding sequences was also carried out and three lipid transfer proteins (LTP) were identified as potential AMPs involved in plant defense. Spathe predicted protein maps were drawn, and suggested that major plant efforts are expended in guaranteeing the maintenance of cell homeostasis, characterized by high investment in carbohydrate, amino acid and energy metabolism as well as in genetic information.
Assuntos
Flores/genética , Flores/metabolismo , Transcriptoma/genética , Zantedeschia/genética , Sequência de Aminoácidos , Anti-Infecciosos/farmacologia , Proteínas de Transporte/química , Ritmo Circadiano/genética , Meio Ambiente , Escherichia coli/efeitos dos fármacos , Flores/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Ligantes , Testes de Sensibilidade Microbiana , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Reguladores de Crescimento de Plantas/metabolismo , Imunidade Vegetal/efeitos dos fármacos , Imunidade Vegetal/genética , Metabolismo Secundário/efeitos dos fármacos , Metabolismo Secundário/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Staphylococcus aureus/efeitos dos fármacos , Extratos de Tecidos , Transcrição Gênica/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Zantedeschia/efeitos dos fármacos , Zantedeschia/imunologiaRESUMO
BACKGROUND: Soybean pathogens and pests reduce grain production worldwide. Biotic interaction cause extensive changes in plant gene expression profile and the data produced by functional genomics studies need validation, usually done by quantitative PCR. Nevertheless, this technique relies on accurate normalization which, in turn, depends upon the proper selection of stable reference genes for each experimental condition. To date, only a few studies were performed to validate reference genes in soybean subjected to biotic stress. Here, we report reference genes validation in soybean during root-knot nematode (Meloidogyne incognita) parasitism and velvetbean caterpillar (Anticarsia gemmatalis) attack. FINDINGS: The expression stability of nine classical reference genes (GmCYP2, GmELF1A, GmELF1B, GmACT11, GmTUB, GmTUA5, GmG6PD, GmUBC2 and GmUBC4) was evaluated using twenty-four experimental samples including different organs, developmental stages, roots infected with M. incognita and leaves attacked by A. gemmatalis. Two different algorithms (geNorm and NormFinder) were used to determine expression stability. GmCYP2 and GmUBC4 are the most stable in different organs. Considering the developmental stages, GmELF1A and GmELF1B genes are the most stable. For spatial and temporal gene expression studies, normalization may be performed using GmUBC4, GmUBC2, GmCYP2 and GmACT11 as reference genes. Our data indicate that both GmELF1A and GmTUA5 are the most stable reference genes for data normalization obtained from soybean roots infected with M. incognita, and GmCYP2 and GmELF1A are the most stable in soybean leaves infested with A. gemmatalis. CONCLUSIONS: Future expression studies using nematode infection and caterpilar infestation in soybean plant may utilize the reference gene sets reported here.
