Long-term nitrogen fertilization alters the partitioning of amino acids between citrus leaves and fruits.

Introduction: The growth of evergreen fruit trees is influenced by the interaction of soil nitrogen (N) and leaf amino acid contents. However, information on free amino acid contents in leaves of fruiting and non-fruiting branches during long-term N fertilizer application remains scarce.

Methods: Here, a four-year field experiment (2018-2021) in a citrus orchard revealed consistently lower total N and amino acid contents in leaves of fruiting compared to non-fruiting branches.

Lead accumulation and concomitant reactive oxygen species (ROS) scavenging in Robinia pseudoacacia are dependent on nitrogen nutrition.

Heavy metal pollution combined with nitrogen (N) limitation is a major factor preventing revegetation of contaminated land. Woody N-fixing legumes are a natural choice for phytoremediation. However, the physiological responses of woody legumes to lead (Pb) with low N exposure are currently unknown.

Pre-Grafting Exposure to Root-Promoting Compounds Improves Top-Grafting Performance of Citrus Trees.

Top grafting is an efficient and practical technique for the renewal and rejuvenation of citrus trees in old orchards. However, root death after top grafting restricts plant growth and canopy reconstruction. Thus, applications of rooting promotion substances before citrus top grafting may increase the amount and activity of roots, thereby enhancing top-grafted plant performance.

Groundcover improves nutrition and growth of citrus trees and reduces water runoff, soil erosion and nutrient loss on sloping farmland.

Introduction: Groundcover management plays a crucial role in improving water retention and soil nutrition in orchard systems, thereby preventing environmental constrains by non-point source pollution. However, effectiveness of groundcover management in citrus orchards developed on sloping farmland with eroded purple soil has not been studied in detail. In particular, information on the soil nutrient losses, , nitrogen (N) and phosphorus (P), through interflow and its effects on growth and nutrition of citrus plants has not been reported.

Date palm diverts organic solutes for root osmotic adjustment and protects leaves from oxidative damage in early drought acclimation.

Date palm (Phoenix dactylifera L.) is an important crop in arid regions that is well-adapted to desert ecosystems. To understand the remarkable ability to grow and yield in water-limited environments, experiments with water-withholding for up to four weeks were conducted.

Biochar amendment affects the microbial genetic profile of the soil, its community structure and phospholipid fatty acid contents.

Biochar (BC) amendment has been proposed as a promising strategy for mitigating greenhouse gas (GHG) emissions, specifically carbon dioxide (CO), methane (CH), and nitrous oxide (NO). Conducting a meta-analysis to evaluate the impact of biochar on microbial genetic profile, community structure, and phospholipid fatty acid (PLFA) contents can aid in identifying key microbial groups involved in GHG production and consumption, and assessing the overall effectiveness of biochar in reducing GHG emissions. The present meta-analysis revealed that the addition of biochar resulted in a 22 % and 41 % reduction in pmoA and mcrA genes of methanogenic microorganisms, respectively.

How to Cope With Stress in the Desert-The Date Palm Approach.

Increasing desertification constitutes a global environmental problem, mainly driven by climate change and inappropriate land-use that limits agriculture, forestry and human colonization. The selection of suitable plant species to mitigate desertification is particularly challenging, as it usually requires simultaneous counteraction against a whole set of unfavourable environmental conditions, including heat, drought, high tropospheric ozone and salinity. It therefore seems useful to identify the survival strategies of plants native in desert environments.

Effects of environmental changes on soil respiration in arid, cold, temperate, and tropical zones.

Soil respiration (R) is projected to be substantially affected by climate change, impacting the storage, equilibrium, and movement of terrestrial carbon (C). However, uncertainties surrounding the responses of R to climate change and soil nitrogen (N) enrichment are linked to mechanisms specific to diverse climate zones. A comprehensive meta-analysis was conducted to address this, evaluating the global effects of warming, increased precipitation, and N enrichment on R across various climate zones and ecosystems.

Sulfur availability and nodulation modify the response of Robinia pseudoacacia L. to lead (Pb) exposure.

Both sulfur (S) supply and legume-rhizobium symbiosis can significantly contribute to enhancing the efficiency of phytoremediation of heavy metals (HMs). However, the regulatory mechanism determining the performance of legumes at lead (Pb) exposure have not been elucidated. Here, we cultivated black locust (Robinia pseudoacacia L.

Water deprivation modifies the metabolic profile of lavender (Lavandula angustifolia Mill.) leaves.

Lavender plantation is globally expanded due to the increasing demand of its essential oil and its popularity as an ornamental species. However, lavender plantations, and consequently essential oil industries, are threatened by more frequent and severe drought episodes in a globally changing climate. Still little is known about the changes in the general metabolome, which provides the precursors of essential oil production, by extended drought events.

Strategies of plants to overcome abiotic and biotic stresses.

In their environment, plants are exposed to a multitude of abiotic and biotic stresses that differ in intensity, duration and severity. As sessile organisms, they cannot escape these stresses, but instead have developed strategies to overcome them or to compensate for the consequences of stress exposure. Defence can take place at different levels and the mechanisms involved are thought to differ in efficiency across these levels.

Co-inoculation of rhizobia and AMF improves growth, nutrient uptake, and cadmium resistance of black locust grown in sand culture.

Rhizobia and arbuscular mycorrhizal fungi (AMF) are symbiotic microorganisms important for plants grown in nutrient-deficient and heavy metal-contaminated soils. However, it remains unclear how plants respond to the coupled stress by heavy metal and nitrogen (N) deficiency under co-inoculation. Here, we investigated the synergistic effect of Mesorhizobium huakuii QD9 and Funneliformis mosseae on the response of black locust (Robinia pseudoacacia L.

Physiological responses of low- and high-cadmium accumulating Robinia pseudoacacia-rhizobium symbioses to cadmium stress.

The role of rhizobia in alleviating cadmium (Cd) stress in woody legumes is still unclear. Therefore, two types of black locust (Robinia pseudoacacia L.) with high and low Cd accumulation abilities were selected from 11 genotypes in China, and the effects of rhizobium (Mesorhizobium huakuii GP1T11) inoculation on the growth, CO and HO gas exchange parameters, Cd accumulation, and the absorption of mineral elements of the high (SX) and low Cd-accumulator (HB) were compared.

Integrated proteome and physiological traits reveal interactive mechanisms of new leaf growth and storage protein degradation with mature leaves of evergreen citrus trees.

The growth of fruit trees depends on the nitrogen (N) remobilization in mature tissues and N acquisition from the soil. However, in evergreen mature citrus (Citrus reticulata Blanco) leaves, proteins with N storage functions and hub molecules involved in driving N remobilization remain largely unknown. Here, we combined proteome and physiological analyses to characterize the spatiotemporal mechanisms of growth of new leaves and storage protein degradation in mature leaves of citrus trees exposed to low-N and high-N fertilization in the field.

Selenium- and chitosan-modified biochars reduce methylmercury contents in rice seeds with recruiting Bacillus to inhibit methylmercury production.

Biochar could reshape microbial communities, thereby altering methylmercury (MeHg) concentrations in rice rhizosphere and seeds. However, it remains unclear whether and how biochar amendment perturbs microbe-mediated MeHg production in mercury (Hg) contaminated paddy soil. Here, we used pinecone-derived biochar and its six modified biochars to reveal the disturbance.

An assessment of ozone risk for date palm suggests that phytotoxic ozone dose nonlinearly affects carbon gain.

Tropospheric ozone (O) is a significant phytotoxic air pollutant that has a negative impact on plant carbon gain. Although date palm (Phoenix dactylifera L.) is a globally important crop in arid or semi-arid regions, so far O risk assessment for this species has not been reported.

Antagonistic effect of mercury and excess nitrogen exposure reveals provenance-specific phytoremediation potential of black locust-rhizobia symbiosis.

Interaction of different environmental constrains pose severe threats to plants that cannot be predicted from individual stress exposure. In this context, mercury (Hg), as a typical toxic and hazardous heavy metal, has recently attracted particular attention. Nitrogen (N)-fixing legumes can be used for phytoremediation of Hg accumulation, whereas N availability could greatly affect its N-fixation efficiency.

Consequences of excess urea application on photosynthetic characteristics and nitrogen metabolism of Robinia pseudoacacia seedlings.

Urea is the most frequently used nitrogen (N) fertilizer worldwide. However, the mechanisms in plants to cope with excess urea are largely unknown, especially for woody legumes that can meet their N demand by their own N-fixation capacity. Here, we studied the immediate consequences of different amounts of urea application and exposure duration on photosynthesis, N metabolism, and the activity of antioxidative enzymes of Robinia pseudoacacia seedlings.

Integrative multi-omics analyses of date palm (Phoenix dactylifera) roots and leaves reveal how the halophyte land plant copes with sea water.

Date palm (Phoenix dactylifera L.) is able to grow and complete its life cycle while being rooted in highly saline soils. Which of the many well-known salt-tolerance strategies are combined to fine-tune this remarkable resilience is unknown.

Bacterial assemblages imply methylmercury production at the rice-soil system.

The plant microbiota can affect plant health and fitness by promoting methylmercury (MeHg) production in paddy soil. Although most well-known mercury (Hg) methylators are observed in the soil, it remains unclear how rice rhizosphere assemblages alter MeHg production. Here, we used network analyses of microbial diversity to identify bulk soil (BS), rhizosphere (RS) and root bacterial networks during rice development at Hg gradients.

The dual role of nitric oxide (NO) in plant responses to cadmium exposure.

Anthropogenic activities such as mining, smelting, and overapplication of fertilizers contribute to introducing cadmium (Cd) into the biosphere. Cd accumulation in edible plants leads to phytotoxicity and reduces biomass formation and food production, posing a significant threat to global food security. Nitric oxide (NO) is a highly active gaseous signalling molecule involved in regulating plant responses to Cd stress.

Significance of nitrogen-fixing actinorhizal symbioses for restoration of depleted, degraded, and contaminated soil.

Atmospheric nitrogen (N)-fixing legume trees are frequently used for the restoration of depleted, degraded, and contaminated soils. However, biological N fixation (BNF) can also be performed by so-called actinorhizal plants. Actinorhizal plants include a high diversity of woody species and therefore can be applied in a broad spectrum of environments.

Plastome variations reveal the distinct evolutionary scenarios of plastomes in the subfamily Cereoideae (Cactaceae).

Background: The cactus family (Cactaceae) has been reported to have evolved a minimal photosynthetic plastome size, with the loss of inverted-repeat (IR) regions and NDH gene suites. However, there are very limited genomic data on the family, especially Cereoideae, the largest subfamily of cacti.

Results: In the present study, we assembled and annotated 35 plastomes, 33 of which were representatives of Cereoideae, alongside 2 previously published plastomes.