Exploring the complexities of rice iron toxicity: Paradoxes, mechanisms, and strategic deliberations.

Iron (Fe) toxicity in rice presents a paradox: excessive soil Fe in tropical flooded soils reduces yields by 15-30 %, yet edible grains remain Fe-deficient, worsening global "hidden hunger", which affects 1.72 billion people. This paradox arises from inefficient Fe translocation from roots to grains and complex research landscapes: field, pot, and hydroponic studies yield conflicting tolerance rankings, hindering mechanistic insights.

Ion toxicity in waterlogged soils: mechanisms of root response and adaptive strategies.

Waterlogging poses a significant global threat to agriculture by inducing ion toxicities (e.g. Fe², Mn², NH ) in roots due to soil redox changes.

The potential risk of microplastics accumulation in farmland soils and vegetables from the development of rural tourism.

Development of rural tourism, such as in the Erhai Lake region of China's Yunnan Province, can lead to significant increases in farmers' incomes. However, the large amounts of plastic waste generated by tourism activities may increase microplastics (MPs) concentrations in surrounding farmland soils and pose a risk to human health. Here, we investigated the abundance and characteristics of MPs in farmland soils and vegetables in the Erhai Lake region.

Ammonium mitigates cadmium toxicity by activating the bZIP20-APX2/CATA transcriptional module in rice seedlings in an ABA-dependent manner.

The amelioration of cadmium (Cd) toxicity in plants by ammonium (NH) has been widely investigated. However, the molecular mechanisms underpinning this amelioration have remained ambiguous. Here, we found that NH significantly reduces Cd accumulation and enhances antioxidant capacity by increasing ABA accumulation, which, in turn, improves Cd tolerance in rice seedlings.

Variation in TaSPL6-D confers salinity tolerance in bread wheat by activating TaHKT1;5-D while preserving yield-related traits.

Na exclusion from above-ground tissues via the Na-selective transporter HKT1;5 is a major salt-tolerance mechanism in crops. Using the expression genome-wide association study and yeast-one-hybrid screening, we identified TaSPL6-D, a transcriptional suppressor of TaHKT1;5-D in bread wheat. SPL6 also targeted HKT1;5 in rice and Brachypodium.

Biological mitigation of soil nitrous oxide emissions by plant metabolites.

Plant metabolites significantly affect soil nitrogen (N) cycling, but their influence on nitrous oxide (NO) emissions has not been quantitatively analyzed on a global scale. We conduct a comprehensive meta-analysis of 173 observations from 42 articles to evaluate global patterns of and principal factors controlling NO emissions in the presence of root exudates and extracts. Overall, plant metabolites promoted soil NO emissions by about 10%.

Physiological and molecular mechanisms of plant-root responses to iron toxicity.

The chemical form and physiological activity of iron (Fe) in soil are dependent on soil pH and redox potential (Eh), and Fe levels in soils are frequently elevated to the point of causing Fe toxicity in plants, with inhibition of normal physiological activities and of growth and development. In this review, we describe how iron toxicity triggers important physiological changes, including nitric-oxide (NO)-mediated potassium (K) efflux at the tips of roots and accumulation of reactive oxygen species (ROS) and reactive nitrogen (RNS) in roots, resulting in physiological stress. We focus on the root system, as the first point of contact with Fe in soil, and describe the key processes engaged in Fe transport, distribution, binding, and other mechanisms that are drawn upon to defend against high-Fe stress.

OsEIL1 is involved in the response to heterogeneous high ammonium in rice: A split-root analysis.

Ammonium (NH) concentrations in rice fields show heterogeneous spatial distribution under the combined influences of nitrogen fertilizer application and modern agronomic practices. However, the characteristics and mechanisms of rice roots in response to heterogeneous NH supply are not well understood. Here, we found a systemic response of rice roots to heterogeneous and high (10 mM) NH supply using a split-root experiment, and show root growth on the NH-free (NO) side was also inhibited by localized high-NH supply.

Plant iron status regulates ammonium-use efficiency through protein N-glycosylation.

Improving nitrogen-use efficiency is an important path toward enhancing crop yield and alleviating the environmental impacts of fertilizer use. Ammonium (NH4+) is the energetically preferred inorganic N source for plants. The interaction of NH4+ with other nutrients is a chief determinant of ammonium-use efficiency (AUE) and of the tipping point toward ammonium toxicity, but these interactions have remained ill-defined.

Nitrogen-loss and carbon-footprint reduction by plant-rhizosphere exudates.

Low-carbon approaches to agriculture constitute a pivotal measure to address the challenge of global climate change. In agroecosystems, rhizosphere exudates are significantly involved in regulating the nitrogen (N) cycle and facilitating belowground chemical communication between plants and soil microbes to reduce direct and indirect emissions of greenhouse gases (GHGs) and control N runoff from cultivated sites into natural water bodies. Here, we discuss specific rhizosphere exudates from plants and microorganisms and the mechanisms by which they reduce N loss and subsequent N pollution in terrestrial and aquatic environments, including biological nitrification inhibitors (BNIs), biological denitrification inhibitors (BDIs), and biological denitrification promoters (BDPs).

Syringic acid from rice roots inhibits soil nitrification and NO emission under red and paddy soils but not a calcareous soil.

Syringic acid (SA) is a novel biological nitrification inhibitor (BNIs) discovered in rice root exudates with significant inhibition of strains. However, the inhibitory effect of SA on nitrification and nitrous oxide (NO) emissions in different soils and the environmental factors controlling the degree of inhibition have not been studied. Using 14-day microcosm incubation, we investigated the effects of different concentrations of SA on nitrification activity, abundance of ammonia-oxidizing microorganisms, and NO emissions in three typical agricultural soils.

The nitrification inhibitor 1,9-decanediol from rice roots promotes root growth in Arabidopsis through involvement of ABA and PIN2-mediated auxin signaling.

1,9-decanediol (1,9-D) is a biological nitrification inhibitor secreted in roots, which effectively inhibits soil nitrifier activity and reduces nitrogen loss from agricultural fields. However, the effects of 1,9-D on plant root growth and the involvement of signaling pathways in the plant response to 1,9-D have not been investigated. Here, we report that 1,9-D, in the 100-400 μM concentration range, promotes primary root length in Arabidopsis seedlings at 3d and 5d, by 10.

Smallholder vegetable farming produces more soil microplastics pollution than large-scale farming.

Microplastics (MPs) accumulation in farmland has attracted global concern. Smallholder farming is the dominant type in China's agriculture. Compared with large-scale farming, smallholder farming is not constrained by restrictive environmental policies and public awareness about pollution.

The Role of Plant Growth Regulators in Modulating Root Architecture and Tolerance to High-Nitrate Stress in Tomato.

Plant growth regulators are known to exert strong influences on plant performance under abiotic stress, including exposure to high nitrate, as occurs commonly in intensive vegetable production. However, direct comparative evaluations of growth regulators under otherwise identical conditions in major crop species are scarce. In this study, tomato ( L.

The good and the bad of preprint servers in plant physiology.

Preprint servers allow rapid publication of research findings by eliminating the time gap between submission and publication associated with editorial and peer review of scientific works. Consequently, non-peer-reviewed articles are essentially accessible immediately to researchers and the public. There are many valid justifications for sharing work on preprint servers, such as the ability to collect feedback from the research community and improve work prior to journal submission and a reduced risk of work being "scooped" by competitors.

OsEIL1 protects rice growth under NH nutrition by regulating OsVTC1-3-dependent N-glycosylation and root NH efflux.

Rice is known for its superior adaptation to ammonium (NH ) as a nitrogen source. Compared to many other cereals, it displays lower NH efflux in roots and higher nitrogen-use efficiency on NH . A critical role for GDP-mannose pyrophosphorylase (VTC1) in controlling root NH fluxes was previously documented in Arabidopsis, but the molecular pathways involved in regulating VTC1-dependent NH efflux remain unclear.

OsGF14b is involved in regulating coarse root and fine root biomass partitioning in response to elevated [CO] in rice.

Elevated [CO] can increase rice biomass and yield, but the degree of this increase varies substantially among cultivars. Little is known about the gene loci involved in the acclimation and adaptation to elevated [CO] in rice. Here, we report on a T-DNA insertion mutant in japonica rice exhibiting a significantly enhanced response to elevated [CO] compared with the wild type (WT).

Coordination of nitrogen uptake and assimilation favours the growth and competitiveness of moso bamboo over native tree species in high-NH environments.

Phenotypic plasticity and competitive strength are major mechanisms determining the success of invasive species and are influenced by abiotic factors. A rise in the ratio of ammonium (NH) to nitrate (NO) in soils is frequently associated with the invasion of bamboo into broad-leaved evergreen forests. However, the influence of soil nitrogen (N) chemistry on plant growth and interspecific competition in the context of invasion remains insufficiently studied.

Stigmasterol root exudation arising from Pseudomonas inoculation of the duckweed rhizosphere enhances nitrogen removal from polluted waters.

Rhizospheric microorganisms such as denitrifying bacteria are able to affect 'rhizobioaugmention' in aquatic plants and can help boost wastewater purification by benefiting plant growth, but little is known about their effects on the production of plant root exudates, and how such exudates may affect microorganismal nitrogen removal. Here, we assess the effects of the rhizospheric Pseudomonas inoculant strain RWX31 on the root exudate profile of the duckweed Spirodela polyrrhiza, using gas chromatography/mass spectrometry. Compared to untreated plants, inoculation with RWX31 specifically induced the exudation of two sterols, stigmasterol and β-sitosterol.

Potassium physiology from Archean to Holocene: A higher-plant perspective.

In this paper, we discuss biological potassium acquisition and utilization processes over an evolutionary timescale, with emphasis on modern vascular plants. The quintessential osmotic and electrical functions of the K ion are shown to be intimately tied to K-transport systems and membrane energization. Several prominent themes in plant K-transport physiology are explored in greater detail, including: (1) channel mediated K acquisition by roots at low external [K]; (2) K loading of root xylem elements by active transport; (3) variations on the theme of K efflux from root cells to the extracellular environment; (4) the veracity and utility of the "affinity" concept in relation to transport systems.

High ammonium inhibits root growth in Arabidopsis thaliana by promoting auxin conjugation rather than inhibiting auxin biosynthesis.

Ammonium (NH) inhibits primary root (PR) growth in most plant species when present even at moderate concentrations. Previous studies have shown that transport of indole-3-acetic acid (IAA) is critical to maintaining root elongation under high-NH stress. However, the precise regulation of IAA homeostasis under high-NH stress (HAS) remains unclear.

Induction of S-nitrosoglutathione reductase protects root growth from ammonium toxicity by regulating potassium homeostasis in Arabidopsis and rice.

Ammonium (NH4+) is toxic to root growth in most plants already at moderate levels of supply, but mechanisms of root growth tolerance to NH4+ remain poorly understood. Here, we report that high levels of NH4+ induce nitric oxide (NO) accumulation, while inhibiting potassium (K+) acquisition via SNO1 (sensitive to nitric oxide 1)/SOS4 (salt overly sensitive 4), leading to the arrest of primary root growth. High levels of NH4+ also stimulated the accumulation of GSNOR (S-nitrosoglutathione reductase) in roots.

Continuous monitoring of plant sodium transport dynamics using clinical PET.

Background: The absorption, translocation, accumulation and excretion of substances are fundamental processes in all organisms including plants, and have been successfully studied using radiotracers labelled with C, N, C and Na since 1939. Sodium is one of the most damaging ions to the growth and productivity of crops. Due to the significance of understanding sodium transport in plants, a significant number of studies have been carried out to examine sodium influx, compartmentation, and efflux using Na- or Na-labeled salts.

Selenium Biofortification and Interaction With Other Elements in Plants: A Review.

Selenium (Se) is an essential element for humans and animals and its deficiency in the diet is a global problem. Crop plants are the main source of Se for consumers. Therefore, there is much interest in understanding the factors that govern the accumulation and distribution of Se in the tissues of crop plants and the mechanisms of interaction of Se absorption and accumulation with other elements, especially with a view toward optimizing Se biofortification.