RESUMEN
Domesticated crops with high yield and quality are frequently susceptible to pathogen attack, whereas enhancement of disease resistance generally compromises crop yield. The underlying mechanisms of how plant development and disease resistance are coordinately programed remain elusive. Here, we showed that the basic Helix-Loop-Helix (bHLH) transcription factor Cucumis sativus Irregular Vasculature Patterning (CsIVP) was highly expressed in cucumber vascular tissues. Knockdown of CsIVP caused severe vasculature disorganization and abnormal organ morphogenesis. CsIVP directly binds to vascular-related regulators YABBY5 (CsYAB5), BREVIPEDICELLUS (CsBP), and AUXIN/INDOLEACETIC ACIDS4 (CsAUX4) and promotes their expression. Knockdown of CsYAB5 resulted in similar phenotypes as CsIVP-RNA interference (RNAi) plants, including disturbed vascular configuration and abnormal organ morphology. Meanwhile, CsIVP-RNAi plants were more resistant to downy mildew and accumulated more salicylic acid (SA). CsIVP physically interacts with NIM1-INTERACTING1 (CsNIMIN1), a negative regulator in the SA signaling pathway. Thus, CsIVP is a novel vasculature regulator functioning in CsYAB5-mediated organ morphogenesis and SA-mediated downy mildew resistance in cucumber.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Cucumis sativus/crecimiento & desarrollo , Cucumis sativus/inmunología , Proteínas de Plantas/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Cucumis sativus/clasificación , Cucumis sativus/genética , Resistencia a la Enfermedad/genética , Expresión Génica , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismo , Morfogénesis , Filogenia , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Haz Vascular de Plantas/genética , Haz Vascular de Plantas/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Unión Proteica , Ácido Salicílico/metabolismo , Transducción de Señal/genéticaRESUMEN
Euphyllophytes encompass almost all extant plants, including two sister clades, ferns and seed plants. Decoding genomes of ferns is the key to deep insight into the origin of euphyllophytes and the evolution of seed plants. Here we report a chromosome-level genome assembly of Adiantum capillus-veneris L., a model homosporous fern. This fern genome comprises 30 pseudochromosomes with a size of 4.8-gigabase and a contig N50 length of 16.22 Mb. Gene co-expression network analysis uncovered that homospore development in ferns has relatively high genetic similarities with that of the pollen in seed plants. Analysing fern defence response expands understanding of evolution and diversity in endogenous bioactive jasmonates in plants. Moreover, comparing fern genomes with those of other land plants reveals changes in gene families important for the evolutionary novelties within the euphyllophyte clade. These results lay a foundation for studies on fern genome evolution and function, as well as the origin and evolution of euphyllophytes.