Abstract
BACKGROUND: The degree of yellowing in tobacco leaves is an important indicator for determining the maturity and harvesting time of tobacco leaves. Decreasing chlorophyll levels helps speed up the ripening process of tobacco leaves for easier mechanical harvesting. Identifying and utilizing genes that regulate yellowing in tobacco leaves are crucial for developing tobacco varieties suitable for mechanized harvesting and understanding the molecular processes that control leaf color changes. RESULTS: In this study, the phenotypes of the yellow-leaf K326 and K326 varieties were analysed, and it was observed that the yellow-leaf K326 variety exhibited a distinct yellow leaf phenotype with a significant reduction in chlorophyll content. Subsequently, using a combination of BSA-seq, transcriptomic sequencing (RNA-seq), and proteomic sequencing approaches, we identified the candidate gene Nitab4.5_0008674g0010 that encodes dihydroneopterin aldolase as a factor associated with tobacco leaf yellowing. Finally, by measuring the folate content in K326 and Huangye K326, the folate content in Huangye K326 was observed to be significantly lower than that in K326, thus indicating that folate synthesis plays a crucial role in phenotypic changes in tobacco yellow leaves. CONCLUSIONS: This study is the first to use BSA-seq combined with RNA-seq and proteomic sequencing to identify candidate genes in tobacco yellow leaves. The results provide a theoretical basis for the analysis of the mechanism of tobacco yellow leaf mutations.