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Tobacco is an important crop. During the flowering period of tobacco cultivation, the top part of plant contains high levels of water and impurities, which affect the taste of tobacco. Therefore, topping operations are carried out. Currently, deep learning is widely used in modern agricultural image recognition, pest and disease management, and other scenarios. However, due to the cost and technology limitations, its application in agricultural production is relatively low. This study proposed a tobacco flowering period recognition technology based on deep learning. An attention mechanism was introduced into the backbone residual module of deep learning to collect tobacco flower characteristic data at different stages to realize tobacco flower identification. Meanwhile, considering the large computational load of the tobacco flower detection model, a cascade strategy and transmembrane segment splitting were introduced to optimize the repeated features in backpropagation and improve the segmentation effect of the model. In the detection model test, compared with the convolutional and the unimproved models, the proposed model improved the recognition effect of tobacco flowers by 45.65% and 28.65%, respectively. In the multi-model comparison, the accuracy of the proposed model in dark light scenes was 0.853, which was better than other models. In the segmentation model test, the proposed model performed best in terms of confidence, time consumption, and number of frames. Improving the segmentation model during training took 3.5 seconds and detected 5 flowers, which was significantly better than the improved tobacco flower detection model and taking less time. The proposed tobacco flower detection model showed good application effects in tobacco flower detection scenarios, took less time, and had high detection accuracy, meeting the production requirements of modern farmers. The research provided important technical references for the management and cultivation of tobacco varieties. [ABSTRACT FROM AUTHOR]

Phosphatidylinositol 3-kinase (PI3K) is a key enzyme that phosphorylates phosphatidylinositol at 3'-hydroxyl position of the inositol head group initiating the generation of several phosphorylated phosphatidylinositols, collectively referred to as phosphoinositides. The function of PI3K in plant senescence and ethylene signal transduction process was studied by expression of Solanum lycopersicum PI3K in transgenic Nicotiana tabacum, and delineating its effect on flower senescence. Detached flowers of transgenic tobacco plants with overexpressed Sl-PI3K (OX) displayed accelerated senescence and reduced longevity, when compared to the flowers of wild type plants. Flowers from PI3K-overexpressing plants showed enhanced ethylene production and upregulated expression of 1-aminocyclopropane-1-carboxylic acid oxidase 1 (ACO1). Real time polymerase chain reaction (PCR) analysis showed that PI3K was expressed at a higher level in OX flowers than in the control. Seedlings of OX-lines also demonstrated a triple response phenotype with characteristic exaggerated apical hook, shorter hypocotyls and increased sensitivity to 1-aminocyclopropane-1-carboxylate than the control wild type seedlings. In floral tissue from OX-lines, Solanum lycopersicum phosphatidylinositol 3-kinase green fluorescent protein (PI3K-GFP) chimera protein was localized primarily in stomata, potentially in cytoplasm and membrane adjacent to stomatal pores in the guard cells. Immunoblot analysis of PI3K expression in OX lines demonstrated increased protein level compared to the control. Results of the present study suggest that PI3K plays a crucial role in senescence by enhancing ethylene biosynthesis and signaling. [ABSTRACT FROM AUTHOR]

Phosphatidylinositol 3-kinase (PI3K) is a key enzyme that phosphorylates phosphatidylinositol at 3’-hydroxyl position of the inositol head group initiating the generation of several phosphorylated phosphatidylinositols, collectively referred to as phosphoinositides. The function of PI3K in plant senescence and ethylene signal transduction process was studied by expression of Solanum lycopersicum PI3K in transgenic Nicotiana tabacum, and delineating its effect on flower senescence. Detached flowers of transgenic tobacco plants with overexpressed Sl-PI3K (OX) displayed accelerated senescence and reduced longevity, when compared to the flowers of wild type plants. Flowers from PI3K-overexpressing plants showed enhanced ethylene production and upregulated expression of 1-aminocyclopropane-1-carboxylic acid oxidase 1 (ACO1). Real time polymerase chain reaction (PCR) analysis showed that PI3K was expressed at a higher level in OX flowers than in the control. Seedlings of OX-lines also demonstrated a triple response phenotype with characteristic exaggerated apical hook, shorter hypocotyls and increased sensitivity to 1-aminocyclopropane-1-carboxylate than the control wild type seedlings. In floral tissue from OX-lines, Solanum lycopersicum phosphatidylinositol 3-kinase green fluorescent protein (PI3K-GFP) chimera protein was localized primarily in stomata, potentially in cytoplasm and membrane adjacent to stomatal pores in the guard cells. Immunoblot analysis of PI3K expression in OX lines demonstrated increased protein level compared to the control. Results of the present study suggest that PI3K plays a crucial role in senescence by enhancing ethylene biosynthesis and signaling.

The effect of addition of different proportions of flowers volatile oil into reconstituted sheet on chemical composition of tobacco smoke was investigated using CO2 supercritical extraction to extract volatile oil from flue-cured tobacco flowers. GC-MS was used to identify the particulate matter from cigarette smoke. The results showed that the total number of volatile components was 74,73,and 88 generated from reconstituted sheet when 0. 1%,0. 2%,and 0. 4% flower volatile oil was added into the sheet,respectively. The number of newly generated compounds was observed to be 38,39,and 52,respectively,and the content of volatile components from smoke condensate was significantly improved compared to the blank control. Through the analysis of the chemical composition of cigarette smoke,the taste was not positively correlated with the addition proportion of volatile oil to reconstituted sheet. [ABSTRACT FROM AUTHOR]

In this article, the author discusses a research related to antioxidant activity potential of Virginia Tobacco Flower polysaccharide obtained by ultrasound-assisted extraction. Topics discussed include four parameters including ultrasound power, extraction time, ratio of solvent to solid, and extraction temperature were optimized by the orthogonal matrix method, crude polysaccharide was purified by sepharose CL-6B column chromatography, and polysaccharides are in cell walls of plants.