%0 Journal Article %A PENG Cuiyun %A WANG Haiyan %A SHI Hongzhi %A GUO Hui %A YANG Huijuan %T Physiological Indexes and Metabolomics Changes in the Upper Stalk Tobacco Leaves Under the Delaying Harvesting in Yuzhong Area %D 2021 %R 10.11869/j.issn.100-8551.2021.11.2655 %J Journal of Nuclear Agricultural Sciences %P 2655-2663 %V 35 %N 11 %X

In order to explore the effects of delayed harvesting practice on the physiological indexes and metabolomics of upper leaves of Yuzhong flue-cured tobacco, Zhongyan 100 was used as experimental material to study the effects of delayed harvesting practice on antioxidant indexes, key enzyme activities of nitrogen metabolism, reducing sugar content and metabolomics of upper leaves. Results showed that with the extension of delayed harvesting time, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in the antioxidant system of tobacco leaves were decreased gradually, while the contents of malondialdehyde (MDA) and proline (Pro) were increased compared with the normal harvesting way. Compared with conventional harvesting method, the content of reducing sugar in upper tobacco leaves reached the highest level when the harvesting was delayed for 8 days, which increased by 97.10%. The activities of nitrate reductase (NR) and glutamine synthase (GS), the key enzymes in nitrogen metabolism, decreased gradually with the prolongation of harvesting time, and reached the lowest level after 16 days’ delaying. The time series analysis (STEM) of metabolites from upper tobacco leaves under different treatments showed that the metabolites which had the similar expression patterns were clustered into one group. In addition, KEGG analysis showed that with the prolongation of harvest period, the metabolites which mainly enriched in the biosynthesis of terpenoids and steroids, the metabolism of D-glutamine and D-glutamate, the biosynthesis of unsaturated fatty acids and the biosynthesis of tropane, piperidine and pyridine alkaloids were continuously down-regulated during the whole process. The metabolites which enriched in starch and sucrose metabolic pathways, tyrosine metabolism, plant hormone biosynthesis and other metabolic pathways were down-regulated when delayed for 8 days. In conclusion, in Yuzhong area the best harvesting time for the upper tobacco leaves is 8 days’ delay. This study provides an important theoretical basis for determining the suitable harvesting time of fluc-cured tobacco upper stalk leaves and guiding the field harvest scientifically in Yuzhong area.

%U https://www.hnxb.org.cn/EN/10.11869/j.issn.100-8551.2021.11.2655