Comparison of nitrification inhibitors for mitigating cadmium accumulation in pakchoi and their associated microbial mechanisms.

The use of nitrification inhibitors has been suggested as a strategy to decrease cadmium (Cd) accumulation in crops. However, the most efficient nitrification inhibitor for mitigating crop Cd accumulation remains to be elucidated, and whether and how changes in soil microbial structure are involved in this process also remains unclear. To address these questions, this study applied three commercial nitrification inhibitors, namely, dicyandiamide (DCD), 3,4-dimethylpyrazole phosphate (DMPP), and nitrapyrin (NP), to pakchoi.

Enhanced nitrogen use efficiency, growth and yield of wheat through soil urea hydrolysis inhibition by extract.

Soil urease inhibition slows down the urea hydrolysis and prolongs nitrogen (N) stay in soil, resulting in an increased N uptake by plants. Apart from several chemical urease inhibitors, the urease inhibition potential of plant extracts is rarely reported. In our previous study, the soil urease inhibition by leaf extract was reported; however, its role in relation to growth and yield of wheat () under pot and field conditions remains unknown.

The ferroxidases are critical for Fe(II) oxidation in xylem to ensure a healthy Fe allocation in .

The long-distance transport of iron (Fe) in the xylem is critical for maintaining systemic Fe homeostasis in plants. The loading form of Fe(II) into the xylem and the long-distance translocation form of Fe(III)-citrate have been identified, but how Fe(II) is oxidized to Fe(III) in the xylem remains unknown. Here, we showed that the cell wall-resided ferroxidases LPR1 and LPR2 (LPRs) were both specifically expressed in the vascular tissues of , while disruption of both of them increased Fe(II) in the xylem sap and caused excessive Fe deposition in the xylem vessel wall under Fe-sufficient conditions.

Phytomelatonin and plant mineral nutrition.

Plant mineral nutrition is critical for agricultural productivity and for human nutrition; however, the availability of mineral elements is spatially and temporally heterogeneous in many ecosystems and agricultural landscapes. Nutrient imbalances trigger intricate signalling networks that modulate plant acclimation responses. One signalling agent of particular importance in such networks is phytomelatonin, a pleiotropic molecule with multiple functions.

Inhibition of Enhances Plant Tolerance to Zn Toxicity by Upregulating Pathways Related to Iron Nutrition.

The identification of the key genes regulating plant tolerance to Zn stress is important for enhancing the Zn phytoremediation of targeted plants. Here, we showed that the T-DNA insertion-induced inhibition of the () gene in the mutant greatly improved Zn tolerance, as indicated by increased biomass production and reduced leaf chlorosis. The complementation in the mutant abolished the improvement of Zn tolerance.

Cross-Talk between Hydrogen Peroxide and Nitric Oxide during Plant Development and Responses to Stress.

Nitric oxide (NO) and hydrogen peroxide (HO) are gradually becoming established as critical regulators in plants under physiological and stressful conditions. Strong spatiotemporal correlations in their production and distribution have been identified in various plant biological processes. In this context, NO and HO act synergistically or antagonistically as signals or stress promoters depending on their respective concentrations, engaging in processes such as the hypersensitive response, stomatal movement, and abiotic stress responses.

Molecular functions of nitric oxide and its potential applications in horticultural crops.

Nitric oxide (NO) regulates plant growth, enhances nutrient uptake, and activates disease and stress tolerance mechanisms in most plants, making NO a potential tool for use in improving the yield and quality of horticultural crop species. Although the use of NO in horticulture is still in its infancy, research on NO in model plant species has provided an abundance of valuable information on horticultural crop species. Emerging evidence implies that the bioactivity of NO can occur through many potential mechanisms but occurs mainly through S-nitrosation, the covalent and reversible attachment of NO to cysteine thiol.

[Effects of dicyandiamide on cadmium accumulation in pakchoi under instant soluble nitrogen fertilizers].

We investigated the effects of dicyandiamide (DCD) on the growth and Cd concentrations in pakchoi cultivated under different instant soluble N fertilizers [ammonium sulfate, ammonium sulfate and sodium nitrate (1:1, ammonium/nitrate), and urea] in Cd-contaminated soils. The results showed that the fresh weight of the edible parts of Cd-stressed pakchoi were increased by 583.3%, 41.

Melatonin: A master regulator of plant development and stress responses.

Melatonin is a pleiotropic molecule with multiple functions in plants. Since the discovery of melatonin in plants, numerous studies have provided insight into the biosynthesis, catabolism, and physiological and biochemical functions of this important molecule. Here, we describe the biosynthesis of melatonin from tryptophan, as well as its various degradation pathways in plants.

Melatonin ameliorates aluminum toxicity through enhancing aluminum exclusion and reestablishing redox homeostasis in roots of wheat.

Melatonin is a universal regulator modulating plant development and responses to abiotic stresses. The alteration and potential roles of melatonin in mediating aluminum (Al) tolerance were investigated in two wheat genotypes differing in Al resistance. Using the high-resolution mass spectrometry, we observed that melatonin contents in Xi Aimai-1 were 1.

Alteration of Phenolic Composition in Lettuce ( L.) by Reducing Nitrogen Supply Enhances its Anti-Proliferative Effects on Colorectal Cancer Cells.

Consumption of vegetables rich in phenolic compounds has become a useful method to reduce the risk of developing several types of cancer. This study investigated the potential relationship between the alteration of phenolic compounds in lettuce induced by reduced nitrogen supply and its anti-proliferative effects on Caco-2 colorectal cancer cells. Our results showed that phenolic extracts from lettuce grown under low nitrogen conditions (LP) exhibited better anti-proliferative effects against Caco-2 cells, in part, by interfering with the cell cycle and inducing apoptosis, compared with those from lettuce supplied with adequate nitrogen.

Estimating nutrient uptake requirements for radish in China based on QUEFTS model.

Imbalanced fertilization has caused lower yield and nutrient use efficiency for radish (Raphanus sativus L.) production in China. Estimating nutrient requirements for radish is crucial in optimizing fertilization to resolve the problem.

Reduced nitrogen supply enhances the cellular antioxidant potential of phenolic extracts through alteration of the phenolic composition in lettuce (Lactuca sativa L.).

Background: Nitrogen availability is an important environmental factor that determines the production of phenolic compounds in vegetables, but the relationship between low nitrogen-induced alterations of phenolic compounds in vegetable crops and the cellular antioxidant activities of these compounds remains unclear. This study investigated the effect of reduced nitrogen supply (0.05 mmol L nitrate) on phenolic metabolism in lettuce and the protective role of phenolic extracts against H O -induced oxidative stress in Caco-2 cells by determining cell damage, reactive oxygen species (ROS) content and antioxidant enzyme activities.

The chirality of imazethapyr herbicide selectively affects the bacterial community in soybean field soil.

The chiral herbicide imazethapyr (IM) is frequently used to control weeds in soybean fields in northeast China. However, the impact of IM enantiomers on microbial communities in soil is still unknown. Genetic markers (16S rRNA V3-V4 regions) were used to characterize and evaluate the variation of the bacterial communities potentially effected by IM enantiomers.

Short-Term Nitrate Limitation Prior to Harvest Improves Phenolic Compound Accumulation in Hydroponic-Cultivated Lettuce ( Lactuca sativa L.) without Reducing Shoot Fresh Weight.

Long-term exposure to a low nitrogen supply could effectively improve phenolic content in vegetables, but it also greatly decreases the yield. Therefore, it is necessary to develop cost-effective strategies of nitrogen management to overcome these obstacles. Here, we find that decreasing the nitrogen (NO) supply from 8.

Developmental Responses of Root Hairs to Mg Deficiency.

Magnesium (Mg), an essential element for plants is easily leached in acidic and sandy soils. Magnesium deficiency induces the initiation and elongation of root hairs, which allows the plant roots to acquire more Mg under Mg-limited conditions. However, the signals involved in the regulatory cascade leading to the induction of root hair development under Mg deficiency are largely unknown to date.

Auxin Acts Downstream of Ethylene and Nitric Oxide to Regulate Magnesium Deficiency-Induced Root Hair Development in Arabidopsis thaliana.

This study examines the association of auxin with ethylene and nitric oxide (NO) in regulating the magnesium (Mg) deficiency-induced root hair development in Arabidopsis thaliana. With Mg deficiency, both ethylene and NO promoted the elevation of root auxin levels in roots by inducing the expression of AUXIN-RESISTANT1 (AUX1), PIN-FORMED 1 (PIN1) and PIN2 transporters. In turn, auxin stimulated ethylene and NO production by activating the activities of 1-aminocyclopropane-1-carboxylate (ACC) oxidase (ACO), ACC synthase (ACS), nitrate reductase (NR) and NO synthase-like (NOS-L).

Spatial responses of antioxidative system to aluminum stress in roots of wheat (Triticum aestivum L.) plants.

Aluminum (Al) toxicity associated with acid soils represents one of the biggest limitations to crop production worldwide. The root apex of plants is the major perception site of Al toxicity. In Al stressed wheat primary roots, Al accumulation and loss of plasma membrane integrity were highest in the root apex (0-5mm), and decreased along the root axis (5-25mm).

Aluminum Induces Distinct Changes in the Metabolism of Reactive Oxygen and Nitrogen Species in the Roots of Two Wheat Genotypes with Different Aluminum Resistance.

Aluminum (Al) toxicity in acid soils is a primary factor limiting plant growth and crop yield worldwide. Considerable genotypic variation in resistance to Al toxicity has been observed in many crop species. In wheat (Triticum aestivum L.

Effects of split applications of nitrogen fertilizers on the Cd level and nutritional quality of Chinese cabbage.

Cadmium (Cd) contamination in soil is an increasingly serious problem. Management of plant nutrients has been proposed as a potentially promising strategy for minimizing Cd accumulation in crops grown in contaminated soil. This study investigated the effects of split applications of nitrogen (N) fertilizers on the Cd concentration in Chinese cabbage (Brassica chinensis L.

Slow-release nitrogen fertilizers can improve yield and reduce Cd concentration in pakchoi (Brassica chinensis L.) grown in Cd-contaminated soil.

Cadmium (Cd) pollution in vegetable crops has become a serious problem in recent years. Owing to the limited availability of arable land resources, large areas of Cd-contaminated lands are inevitably being used for the production of vegetables, posing great risks to human health via the food chain. However, strategies to improve yield and reduce Cd concentration in crops grown in contaminated soils are being developed.

Effects of organic amendment on soil aggregation and microbial community composition during drying-rewetting alternation.

The alternation of drying and rewetting events could dramatically affect the biological and structural properties of soil and consequently influence nutrient transformation. To examine whether organic amendments could improve the resistance and resilience of microbial function (extracellular enzyme activities), community composition (phospholipid fatty acids), and soil structure to drying-rewetting alternation, cropland soils with or without wheat-straw amendment were allowed to desiccate in a microcosm for two months, followed by moist incubation for five weeks, and continuously moist treatments were maintained at 50% water holding capacity during the entire period, as a control treatment. Straw amendment increased microbial biomass, extracellular enzyme activities, the relative abundance of fungal groups, dissolved organic carbon, and proportion of large macroaggregates (>2000μm), but decreased mineral nitrogen and available phosphorus.

Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants.

Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5.

Effect of calcium cyanamide, ammonium bicarbonate and lime mixture, and ammonia water on survival of Ralstonia solanacearum and microbial community.

The inorganic nitrogenous amendments calcium cyanamide (CC), ammonia water (AW), and a mixture of ammonium bicarbonate with lime (A+L) are popularly used as fumigants to control soil-borne disease in China. However, it is unclear which of these fumigants is more effective in controlling R. solanacearum.

Decreasing methylation of pectin caused by nitric oxide leads to higher aluminium binding in cell walls and greater aluminium sensitivity of wheat roots.

Nitric oxide (NO) is an important bioactive molecule involved in cell wall metabolism, which has been recognized as a major target of aluminium (Al) toxicity. We have investigated the effects of Al-induced NO production on cell wall composition and the subsequent Al-binding capacity in roots of an Al-sensitive cultivar of wheat (Triticum aestivum L. cv.