RESUMO
Mirabilis himalaica is an endangered medicinal plant species in the Tibetan Plateau. The two genes respectively encoding chalcone synthase (MhCHS) and chalcone isomerase (MhCHI) were isolated and characterized from M. himalaica. The sequence analysis revealed that the two genes were similar with their corresponding homologous genes in other plants. The tissue profiles showed that both MhCHS and MhCHI had higher expression levels in roots than in stems and leaves. Transgenic hairy root cultures respectively with overexpressing MhCHS and MhCHI were established. The genomic PCR detection confirmed the authority of transgenic hairy root lines, in which either MhCHS or MhCHI expression levels were much higher than that in non-transgenic hairy root line. Finally, the HPLC detection results demonstrated that the rotenoid contents in MhCHS/MhCHI-transformed hairy root lines were enhanced. This study provided two candidate genes that could be used to genetic engineering rotenoid biosynthesis in M. himalaica and an alternative method to produce rotenoid using transgenic hairy root cultures.
Assuntos
Aciltransferases/genética , Liases Intramoleculares/genética , Mirabilis/genética , Transgenes/genética , Aciltransferases/química , Aciltransferases/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Liases Intramoleculares/química , Liases Intramoleculares/metabolismo , Mirabilis/citologia , Mirabilis/enzimologia , Mirabilis/metabolismo , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Rotenona/metabolismo , Análise de Sequência de DNARESUMO
Accelerated gene evolution is a hallmark of pathogen adaptation following a host jump. Here, we describe the biochemical basis of adaptation and specialization of a plant pathogen effector after its colonization of a new host. Orthologous protease inhibitor effectors from the Irish potato famine pathogen, Phytophthora infestans, and its sister species, Phytophthora mirabilis, which is responsible for infection of Mirabilis jalapa, are adapted to protease targets unique to their respective host plants. Amino acid polymorphisms in both the inhibitors and their target proteases underpin this biochemical specialization. Our results link effector specialization to diversification and speciation of this plant pathogen.