Metabolome and molecular basis for carbohydrate increase and nitrate reduction in burley tobacco seedlings by glycerol through upregulating carbon and nitrogen metabolism

Abstract

Burley tobacco (Nicotiana Tabacum) is a chlorophyll-deficiency mutant. Nitrate is one precursor of tobacco-specific nitrosamines (TSNAs) and is largely accumulated in burley tobacco. To decrease nitrate accumulation in burley tobacco, glycerol, a polyhydric alcohol compound and physiological regulating material, was sprayed and its effects were investigated based on metabolomic technology and molecular biology. The results showed that glucose, glutamine and glutamic acid increased by 2.6, 5.1 and 196, folds, respectively, in tobacco leaves after glycerol application. Nitrate content was significantly decreased by 12–16% and expression of eight genes responsible for carbon and nitrogen metabolism were up-regulated with glycerol applications under both normal and 20% reduced nitrogen levels (P < 0.01). Leaf biomass of plants sprayed with glycerol and 20% nitrogen reduction was equivalent to that of no glycerol control with normal nitrogen application. Carbohydrates biosynthesis, nitrate transport and nitrate assimilation were enhanced in glycerol sprayed burley tobacco seedlings which might contribute to reduced nitrate and increased carbohydrates contents. In conclusion, glyerol spray coupled with 20% nitrogen reduction would be an effective method to reduce nitrate accumulation in burley tobacco.

A Review of Environment Effects on Nitrate Accumulation in Leafy Vegetables Grown in Controlled Environments

“…Photoperiod or light duration is another vital environmental factor regulating plant flowering, morphogenesis, and metabolism. The extension of light duration or modification of the photoperiod using artificial light sources can increase carbohydrate synthesis, which stimulates nitrate assimilation by providing a continuous supply of reductant energy and carbon skeletons [ 48 ]. After being taken up from the soil and transported into different organs, nitrates are generally stored in the vacuole in the dark [ 49 ].…”

A comprehensive study on the relieving effect of Lilium brownii on the intestinal flora and metabolic disorder in p -chlorphenylalanine induced insomnia rats

“… 2017 ; Li et al. 2018 ). Moreover, metabolomics is accepted to comprehensively evaluate endogenous metabolites of a biological system holistically, and its property is consistent with the holistic efficacy of Chinese medicine (Yang et al.…”

“…Simultaneously, a growing number of studies prove that gut microbiota interferes with gastrointestinal physiology, metabolism, and immune function of the host, and influences central nervous system (CNS) function and behaviour via the microbiota-gut-brain (MGB) axis (Foster and McVey Neufeld 2013 ; Luna and Foster 2015 ; Li et al. 2018 ). The delicate imbalance of gut microbiota is implicated in numerous human diseases, such as sleep loss, circadian misalignment, affective disorders, and metabolic disease (Agus et al.…”

Phenotypic and transcriptomic responses of the sun- and shade-loving plants to sunlight and dim-light conditions

“…In ginseng, however, the two advantageous phenotypes may not only provide resource of energy during seed gemination but also increase the capacity to capture limited light under shaded habitat. For physiological traits, both the one-year and four-year ginseng plants possessed relatively lower light saturation point (300-400 μmol·m -2 ·s -1 ) compared to Arabidopsis (700-800 μmol·m -2 ·s -1 ) and other heliophytic plant species (600-1000 μmol·m -2 ·s -1 ) (Boonchai et al ., 2018; Li et al ., 2018). In particular, we showed that both one-year and four-year ginseng plants exhibited significantly higher Fv/Fm values under dim-light compared to sunlight condition.…”