RESUMO
KEY MESSAGE: A gene encoding a coproporphyrinogen III oxidase mediates disease resistance in plants by the salicylic acid pathway. A number of genes that regulate powdery mildew resistance have been identified in Arabidopsis, such as ENHANCED DISEASE RESISTANCE 1 to 3 (EDR1 to 3). To further study the molecular interactions between the powdery mildew pathogen and Arabidopsis, we isolated and characterized a mutant that exhibited enhanced resistance to powdery mildew. The mutant also showed dramatic powdery mildew-induced cell death as well as growth defects and early senescence in the absence of pathogens. We identified the affected gene by map-based cloning and found that the gene encodes a coproporphyrinogen III oxidase, a key enzyme in the tetrapyrrole biosynthesis pathway, previously known as LESION INITIATION 2 (LIN2). Therefore, we designated the mutant lin2-2. Further studies revealed that the lin2-2 mutant also displayed enhanced resistance to Hyaloperonospora arabidopsidis (H.a.) Noco2. Genetic analysis showed that the lin2-2-mediated disease resistance and spontaneous cell death were dependent on PHYTOALEXIN DEFICIENT 4 (PAD4), SALICYLIC ACID INDUCTION-DEFICIENT 2 (SID2), and NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), which are all involved in salicylic acid signaling. Furthermore, the relative expression levels of defense-related genes were induced after powdery mildew infection in the lin2-2 mutant. These data indicated that LIN2 plays an important role in cell death control and defense responses in plants.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/microbiologia , Coproporfirinogênio Oxidase/genética , Resistência à Doença/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Ascomicetos/patogenicidade , Sequência de Bases , Morte Celular/genética , Coproporfirinogênio Oxidase/metabolismo , Ciclopentanos/metabolismo , Etilenos/metabolismo , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas , Dados de Sequência Molecular , Mutação , Oomicetos/patogenicidade , Oxilipinas/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Ácido Salicílico/metabolismoRESUMO
Somatic embryogenesis receptor-like kinase (SERK) genes were identified in different plant species, such as Daucus carota, Arabidopsis thaliana and Oryza sativa. Studies of these genes showed that they have conserved structures and expression patterns. These genes are not only expressed in embryogenic tissues, but also in post-embryogenic development. They function in embryogenesis and reproductive development and defences in particular, related signal transduction pathways.
Assuntos
Perfilação da Expressão Gênica , Proteínas de Plantas/genética , Plantas/genética , Proteínas Quinases/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Proteínas Quinases/metabolismoRESUMO
Gibberellins (GAs) is a sort of high efficiency plant growth regulator which is very important for cotton fiber initiation and development. Recently, the research of GA signal transduction mostly focuses on Arabidopsis, wheat, barley, maize, rice and so on. Yet we know little about molecular mechanism of GA to cotton fiber initiation and development. In recent years, exciting progress has been made in identifying many important components involved in gibberellin signal transduction pathways, which can help us to understand deeply these pathways and their regulation. This review summarized the recently research process of GA signal transduction and correlation of GA and cotton fiber' molecular development. We hope that the paper can provide some new ideas about the function and mechanism of GA in cotton fiber initiation and development, and for cotton breeding task.