RESUMO
BACKGROUND: Pomegranate (Punica granatum L.) is a tropical fruit crop of pharma-nutritional importance. However, it faces farming challenges due to pests and diseases, particularly bacterial blight and wilt. Developing resistant cultivars is crucial for sustainable pomegranate cultivation, and understanding resistance's genetic basis is essential. METHODS AND RESULTS: We used an extensive resistance gene analogues (RGA) prediction tool to identify 958 RGAs, classified into Nucleotide Binding Site-leucine-rich repeat (NBS-LRR) proteins, receptor-like kinases (RLKs), receptor-like proteins (RLPs), Transmembrane coiled-coil (TM-CC), and nine non-canonical RGAs. RGAs were distributed across all eight chromosomes, with chromosome 02 containing the most RGAs (161), and chromosome 08 having the highest density (4.42 RGA/Mb). NBS-LRR genes were predominantly present on chromosomes 08 and 02, whereas RLKs and RLPs were primarily located on chromosomes 04 and 07. Gene ontology analysis revealed that 475 RGAs were associated with defence against various biotic stresses. Using RNAseq, we identified 120 differentially expressed RGAs, with RLKs (74) being prominent among the differentially expressed genes. CONCLUSION: The discovery of these RGAs is a significant step towards breeding pomegranates for pest and disease resistance. The differentially expressed RLKs hold promise for developing resistant cultivars against bacterial blight, thereby contributing to the sustainability of pomegranate cultivation.
Assuntos
Resistência à Doença , Doenças das Plantas , Proteínas de Plantas , Punica granatum , Transcriptoma , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Punica granatum/genética , Transcriptoma/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genoma de Planta , Regulação da Expressão Gênica de Plantas , Perfilação da Expressão Gênica/métodos , Xanthomonas/patogenicidadeRESUMO
Xanthomonas citri pv. punicae causing bacterial blight is a devastating disease of pomegranate in India and Pakistan. Most xanthomonads use the type III secretion system to inject transcription activator-like effector (TALE) proteins into the host cell. TALEs bind to the effector-binding elements in the promoter of host susceptibility genes, triggering disease development. PacBio single-molecule real-time long-read sequencing technology was used to identify the TALE-encoding genes, which is otherwise not possible using next-generation short-read sequencers. In all, 1.74 Gb of raw data containing 368,980 subreads, with an average read length of 4,724 bp and longest read length of 77,471, were generated. Subreads were assembled into 15 scaffolds generating approximately 5.4 Mb (348×) of genome. X. citri pv. punicae exhibited close lineage with X. citri pv. citri with 98.78% average nucleotide identity. Of the 4,263 protein-coding genes, 11 non-TALE type III effectors and 2 TALE-encoding genes were identified.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
