Differential Analysis of Nutrient Content and Metabolism of Camellia oleifera at Different Growing Periods

In order to indicate the variations in nutrient content, gene expression associated with nitrogen metabolism, and starch and sucrose metabolism in C. oleifera at different growing periods, leaves from the C. oleifera 'Dabieshan 1' cultivar were collected at the juvenile (2-year-old C. oleifera), early fruiting stage(6-year-old C. oleifera), and peak fruiting stages(10-year-old C. oleifera), which were selected as experimental materials. Determination of nutrient content and analysis of transcriptome sequencing were conducted on leaf samples in the early flowering stage, systematically studying the content of nutrients and related metabolic pathways of C. oleifera during different growing periods. The results distinguished 9 homologous genes related to nitrogen metabolism and 24 related to starch and sucrose metabolism, respectively, after subjecting the C. oleifera leaves collected during both the juvenile and the peak fruiting stage to comparison in the KEGG database. With increasing tree age, changes in the nitrogen metabolism and the starch and sucrose metabolic pathways in C. oleiferaleaves. C. oleifera would enhance both the phenylalanine ammonia-lyase pathway and sucrose biosynthesis. These ultimately led to increased levels of soluble proteins and soluble sugars in C. oleifera leaves. This study provides new insights into the mechanisms of changes in nitrogen metabolism, starch and sucrose metabolism, and nutrient content during the transformation of C. oleifera from vegetative growth to reproductive growth. It offers theoretical references for understanding its fruiting period and applying plant foliar fertilizers to promote flowering and fruiting.