| Popis: |
Leaf color mutations are excellent research tools for understanding the mechanics of pigment metabolism, chloroplast development, and photosynthesis. Chloroplasts and photosynthetic pigments in leaf cells of plants both play a significant role in determining the photosynthetic efficiency, as well as crop productivity to a greater extent. Leaf color has been regarded as an essential agronomic trait in rice (Oryza sativa L.) majorly because any changes in leaf color have an impact on rice yield. In this study, M-507, a green-revertible albino mutant of Nagina 22 (N22), was characterized and compared to wild-type in terms of anatomical, physiological, and molecular similarities. The mutant showed significantly lower chlorophyll content, defective chloroplast morphology, and reduced photosynthetic capacity than the wild-type. The differentially expressed genes (DEGs) were identified in M-507 with respect to wild-type using high-throughput transcriptome sequencing revealed downregulation of genes essential for the synthesis of chlorophyll, carotenoid, anthocyanin, and photosynthesis pathway. Whereas, genes associated with chlorophyll degradation, ion transport, and starch and sucrose metabolism were remarkably up-regulated in M-507. Co-expression networking revealed a substantial positive correlation between the expression profiles of the chloroplastic genes, transcription factors, and the genes involved in pigment metabolism and starch and sucrose metabolism. Furthermore, sequence similarity analysis revealed existing single-nucleotide polymorphism (SNP) and Insertions and Deletions (InDels) in M-507 as compared to N22. The identified SNPs and InDels candidate genes have been found to have strong associated positive and negative expression quantitative trait loci (eQTLs). Additionally, transcription factor family genes, including NAC, bHLH, WRKY, AP2/ERF, and MYB, were also identified. Real-time quantitative PCR (qPCR) was used to confirm the reliability of RNA sequencing results. These findings provide a possible pathway for the molecular mechanism associated with leaf color formation as well as a valuable resource for molecular marker development, that will be critical for improving rice crop production efficiency. |
