Phosphorus Conditions Research Articles

Genome-wide identification and expression analysis of CASPL gene family in Zea mays (L.)

Casparian strip membrane domain proteins like (CASPL), exhibit profound associations with root development, stress responsiveness and mineral element uptake in plants. Nonetheless, a comprehensive bioinformatics analysis of the ZmCASPL gene family in maize remains unreported. In the study, we have identified 47 ZmCASPL members at the whole-genome level, systematically classifying them into six distinct groups. Furthermore, our analysis revealed that the same group of ZmCASPL contains similar gene structures and conserved motifs. Duplication events showed whole genome duplication (WGD) and tandem duplication (TD) contribute to the generation of the ZmCASPL gene family together in maize, but the former plays a more prominent role. Furthermore, we observed that most ZmCASPL genes contain MYB-binding sites (CAACCA), which are associated with the Casparian strip. Utilizing RNA-seq data, we found that ZmCASPL21 and ZmCASPL47 are specifically highly expressed only in the roots. This finding implies that ZmCASPL21 and ZmCASPL47 may be involved in the Casparian strip development. Additionally, RNA-seq analysis illuminated that drought, salt, heat, cold stresses, low nitrogen and phosphorus conditions, as well as pathogen infection, significantly impact the expression patterns of ZmCASPL genes. RT-qPCR revealed that ZmCASPL 5/13/25/44 genes showed different expression patterns under PEG and NaCl treatments. Collectively, these findings provide a robust theoretical foundation for further investigations into the functional roles of the ZmCASPL gene family in maize.

Different elemental stoichiometries of Fe‐limited Trichodesmium when grown under inorganic and organic phosphorus sources

AbstractTrichodesmium spp. is a colonial diazotrophic cyanobacterium found in the oligotrophic (sub)tropical oceans, where its distribution is strongly regulated by the availability of phosphorus and iron. The bulk carbon : nitrogen : phosphorus elemental composition of phytoplankton has previously been shown to depart from classical “Redfield” values under nutrient‐limitation conditions. We hypothesized that the abundance of intracellular metabolites and the extended Redfield ratios of Trichodesmium, including a range of trace elements, are variable in response to conditions of phosphorus and iron limitation that are found in the ocean. To test this, we grew Trichodesmium under trace metal–controlled conditions, where phosphorus was supplied as either dissolved inorganic phosphorus (DIP) or dissolved organic phosphorus (DOP) from iron depleted to elevated levels. We found that the steady‐state extended Redfield ratios of Trichodesmium under the iron‐depleted condition was (C106N15.82P0.62)1000Fe2.26Zn2.37Mn1.68Cu0.68Ni0.31Mo0.42Co0.03 for the DIP treatment where Trichodesmium was under iron limitation, and (C106N13.89P0.49)1000Fe3.38Zn2.51Mn0.97Cu0.52Ni0.42Mo0.33Co0.03 for the DOP treatment where Trichodesmium was under iron–phosphorus co‐limitation. Mean steady‐state cellular iron : carbon in the DIP treatment (iron limited) was only 50% of that in the control treatment, while zinc : carbon was elevated twofold. The average extended Redfield ratios following recovery from iron limitation was (C106N16.8P0.7)1000Fe4.41Zn1.44Mn1Cu0.52Ni0.19Mo0.3Co0.03 for the DIP and (C106N15.9P0.73)1000Fe7.36Zn2.24Mn1.08Cu0.71Ni0.63Mo0.38Co0.02 for the DOP treatment. No significant changes were observed in the carbon‐normalized abundance of targeted metabolites produced by Trichodesmium, under the different treatments. These results suggest Trichodesmium employs different strategies to cope with iron/phosphorus limitation, which is reflected in its extended Redfield ratios.

Ammonium nutrition enhances rhizosphere mobilization and uptake of silicon in white lupin grown in low phosphorus soil

Abstract Background and Aims While nitrogen (N) supply can enhance plant silicon (Si) accumulation, the mechanisms by which different forms of N affect Si mobilization in the rhizosphere are not well understood. This study aims to elucidate how pH changes induced by ammonium (NH4+) and nitrate (NO3−) affect Si availability in the rhizosphere, especially under low phosphorus (P) conditions. Methods White lupin (Lupinus albus) plants were grown in non-fertilized low-P soil, supplied with a low dose of N, either as NH4+ or NO3−, with or without supply of monosilicic acid. We measured Si levels in various rhizosphere soil pools, along with different plant and rhizosphere soil parameters. Results The addition of NH4+ significantly lowered rhizosphere pH and decreased both Si adsorbed to pedogenic Fe/Mn oxides and amorphous phytogenic Si, resulting in higher concentrations of plant available Si in the white lupin rhizosphere. This led to greater Si uptake and improved plant growth compared to both the –N and + NO3− treatments. The supply of Si further enhanced these effects, with NH4+ showing a consistently different pattern of influence compared to NO3−. Additionally, –N white lupin plants accumulated more P than those treated with N, while Si supply significantly improved P acquisition across all treatments. Conclusions Our study demonstrates that rhizosphere acidification induced by NH4+ nutrition can significantly enhance Si mobilization from the rhizosphere soil in the absence of Si supply and reduce Si adsorption when Si is applied. These findings may have practical implications for improving both Si mobilization in the rhizosphere and the effectiveness of Si fertilizers.

Phosphorus mitigates the adverse effects of microplastics pollution on wheat and maize: Impacts on growth, photosynthesis, and antioxidant defense

Microplastics (MP) pollution in agricultural soils has become an important environmental problem. Phosphorus (P) is a key nutrient for plant growth. P fertilizers are mainly applied to agricultural fields to achieve the high production expected by farmers. The experiment included two MP levels (0, 1 % w/w) and two P levels (0 mg kg−1, 200 mg kg−1) in order to know whether MP effects on wheat and maize are regulated by supplemental P supply. MP decreased plant height, photosynthetic pigment, and chlorophyll fluorescence parameters, while increased ROS and MDA contents. Wheat and maize exhibited distinct strategies in mitigating growth damage caused by MP pollution: wheat primarily increased the AsA contents, while maize predominantly enhanced APX activity. P supply alleviated the MP pollution effect by improving photosynthetic pigments, POD, and PPO activity in wheat and maize. P supply alleviated the MP pollution effect by improving antioxidant enzyme activities in the AsA-GSH cycling in wheat, while increasing non-enzymatic antioxidant contents in the AsA-GSH cycling in maize. The results showed that wheat and maize resisted MP pollution by different mechanisms, and P supply reduced the sensitivity of wheat and maize to MP pollution and its regulatory effect on wheat was better than that on maize. SynopsisThe response of different plants under the same microplastic and phosphorus conditions is limited. We find phosphorus alleviates microplastics pollution on wheat and maize through different regulatory routes.

Analysis and profiling of the purple acid phosphatase gene family in wheat (Triticum aestivum L.).

Purple acid phosphatases (PAPs) play a vital role in plant phosphorus nutrition, serving as a crucial family of metallo-phosphoesterase enzymes. This research aimed to identify the PAP genes from the A/B/D genomes of Triticum aestivum to elucidate evolutionary mechanisms of the gene family in plants and provide genomic information for subsequent research on phosphorous-use efficiency in wheat crops. In total, 105 PAP genes (TaPAPs) were identified from the A/B/D genomes by using the Arabidopsis thaliana and Oryza sativa PAP protein sequences as queries for BLASTP against the wheat protein database. The TaPAPs were grouped into six subfamilies, Ia (17), Ib (26), IIa (11), IIb (30), IIIa (12), and IIIb (9), based on their similarities in the structure of genes and the presence of conserved protein motifs. A majority of TaPAPs were derived from tandemly (20) or segmentally (87) duplicated, with the homoeologous chromosomes 5A/B/D harboring the most duplicated PAP genes. Further analysis indicated that TaPAPs were responsible for the modulation of seed, root, and leaf development and hormone synthesis and signaling, as well as plant responses to abiotic stresses, including low temperatures, drought, and anaerobic conditions. Nine TaPAPs (TaPAP9-4A/4B/4D, TaPAP24-6A/6B/6D, and TaPAP28-7A/7B/7D) were constitutively expressed in diverse tissues such as root, shoot, leaf, spike, and seed, while the remaining genes exhibited tissue-specific expression patterns. Concerning the response to phosphate (Pi) deprivation, 57 TaPAPs were highly expressed in roots under Pi stress, including TaPAP31-4A, 4B, and 4D homeologs from the subfamily IIIb. A TaPAP31-4A transgene in A. thaliana promoted plant growth and development while increasing plant resistance to Pi-deficiency stress by enhancing the secretion of phosphatase. These discoveries provide a scientific foundation for comprehending the role of TaPAPs, offering valuable insights for identifying additional candidate genes and fostering the development of new wheat varieties with enhanced tolerance to low phosphorus conditions.

Crop domestication increased photosynthetic phosphorus-use efficiency associated with changes in leaf phosphorus fractions under low soil phosphorus conditions

Crop domestication increased photosynthetic phosphorus-use efficiency associated with changes in leaf phosphorus fractions under low soil phosphorus conditions

Effect of long-term nitrogen addition on the kinetics of phosphatases in a subtropical forest in southern China

Numerous studies have explored the effects of nitrogen (N) addition on the maximum rate of substrate conversion (Vmax) of phosphatase activity, whereas how N fertilization affects the substrate affinity (the Michaelis constant, Km) of phosphatases is not well understood. Here, we examined a recently-proposed novel hypothesis suggesting that N addition enhances the adaptability of soil microorganisms to low phosphorus (P) conditions by both increasing phosphatase abundance (i.e., increasing the Vmax of phosphatases) and enhancing the substrate-binding affinity of phosphatases (i.e., diminishing the Km of phosphatases). Contrary to the hypothesis, our study found that no level of N addition led to changes in either Vmax or Km of phosphatases in our study site. Furthermore, we observed a positive correlation between Vmax and Km, which challenges the proposed hypothesis, as this positive relationship contradicts the condition suggested by the hypothesis that the adaptive response of increasing phosphatase abundance (higher Vmax) should be associated with increased substrate affinity (lower Km). In conclusion, the present study indicates that N addition does not necessarily enhance the substrate affinity of phosphatases.

CAMKK2-AMPK axis endows dietary calcium and phosphorus levels with regulatory effects on lipid metabolism in weaned piglets

BackgroundIn the realm of swine production, optimizing body composition and reducing excessive fat accumulation is critical for enhancing both economic efficiency and meat quality. Despite the acknowledged impact of dietary calcium (Ca) and phosphorus (P) on lipid metabolism, the precise mechanisms behind their synergistic effects on fat metabolism remain elusive.ResultsResearch observations have shown a decreasing trend in the percentage of crude fat in carcasses with increased calcium and phosphorus content in feed. Concurrently, serum glucose concentrations significantly decreased, though differences in other lipid metabolism-related indicators were not significant across groups. Under conditions of low calcium and phosphorus, there is a significant suppression in the expression of FABPs, CD36 and PPARγ in the jejunum and ileum, leading to inhibited intestinal lipid absorption. Concurrently, this results in a marked increase in lipid accumulation in the liver. Conversely, higher levels of dietary calcium and phosphorus promoted intestinal lipid absorption and reduced liver lipid accumulation, with these changes being facilitated through the activation of the CAMKK2/AMPK signaling pathway by high-calcium-phosphorus diets. Additionally, the levels of calcium and phosphorus in the diet significantly altered the composition of liver lipids and the gut microbiota, increasing α-diversity and affecting the abundance of specific bacterial families related to lipid metabolism.ConclusionThe evidence we provide indicates that the levels of calcium and phosphorus in the diet alter body fat content and lipid metabolism by modulating the response of the gut-liver axis to lipids. These effects are closely associated with the activation of the CAMKK2/AMPK signaling pathway.

Effects of earthworm and arbuscular mycorrhizal fungal inoculation on carbon component accumulation and allocation in rocky desertification soils.

Exploring the responses of carbon component accumulation and allocation to arbuscular mycocorrhizal fungi (AM) and earthworm inoculation can provide reference for improving carbon sequestration potential and bioremediation efficiency in rocky desertification soils. In this study, we chose Fraxinus malacophylla as the host plant to inoculate with Funneliformis mosseae (FM), earthworm (E), and E+FM, using no earthworm and mycorrhizae addition as CK to examine the spatiotemporal variations in soil carbon components (i.e., total organic carbon, microbial biomass carbon, easily oxidized organic carbon, and recalcitrant organic carbon) and their allocation (i.e., microbial biomass carbon/total organic carbon, easily oxidized organic carbon/total organic carbon, and recalcitrant organic carbon/total organic carbon). The results showed that 1) The respective and interactive inoculation of E and AM significantly promoted the accumulation of each carbon component. In contrast with the control, the average carbon component levels under three inoculation treatments were ranked as E+FM>E>FM. The three inoculation treatments significantly promoted soil microbial carbon/total organic carbon (30.5%-68.5%) and easily oxidized carbon/total organic carbon (31.2%-39.2%), but decreased recalcitrant organic carbon/total organic carbon (2.9%-16.2%). 2) The spatiotemporal variation in accumulation and allocation of soil carbon components varied between the inoculation treatments. The maximum value of each carbon component occurred in June. The increase in each carbon component was significantly higher in E+FM (33.0%-122.1%) than that in E (31.2%-95.4%) and FM (9.2%-41.3%). The maximum value of microbial biomass carbon/total organic carbon and easily oxidized organic carbon/total organic carbon was observed in June, while that of recalcitrant organic carbon/total organic carbon was recorded in December. In contrast with CK, the amplitude of variation in the proportion of carbon components in total organic carbon under the three inoculation treatments was ranked as E+FM>E>FM. The accumulation and allocation of all carbon components decreased (9.7%-146.2%) along the soil profile. The level of carbon components in the E treatment decreased the smallest. The microbial biomass carbon/total organic carbon and easily oxidized carbon/total organic carbon decreased the least and the recalcitrant organic carbon/total organic carbon decreased the greatest under the E+FM treatment. 3) Changes in soil physicochemical properties under the three inoculation treatments significantly affected the accumulation and allocation of organic carbon components. Soil pH was negatively correlated with carbon component accumulation and allocation, whereas other soil variables were positively correlated with them. 4) The results of principal component analysis showed that soil water content, total nitrogen, and total phosphorus were the main factors driving carbon component accumulation, while soil water content, total phosphorus, and pH were the main factors controlling carbon component allocation. Therefore, we concluded that the earthworms, AM fungi and their interaction affected the accumulation and allocation of carbon components in Yunnan rocky desertification soils, which would primarily depend on the changes of soil water content, acid-base property, as well as nitrogen and phosphorus conditions.

Responses of crops for diverse soil phosphorus conditions and potential crops for phytoextraction of enriched soil phosphorus

Phytoextraction is an attractive method to extract excess soil phosphorus (P) builds up from the soils. The crops potential to extract an enriched P in soil is still lacking. Therefore, four crops were grown in three different soils with variable P levels (0 to 200 mg P/kg soil) and screened for P acquisition potentials. Total P accumulation in roots and shoot was high with enriched P levels in all soils, for example in soil A at 200 mg P/kg soil, the values were 0.44% for cucumber (Cucumis sativus), 0.40% for sunflower (Helianthus annus), and ∼0.30% for cabbage (Brassica oleracea) and 0.20% for Indian mustard (Brassica juncea). The cucumber and sunflower showed a greater biomass production (>6.0 g/pot) with enriched P levels and exhibited more prominent root characteristics, suggests more favorable for P acquisition from the P enriched soils. More prominent enhanced phosphomonoesterase and phytase activities in these crops possibly contributing to their P accumulation ability under high soil P conditions. This study shows that, cucumber and sunflower can generate high dry matter content and can accumulate greater quantity of P from the soils through different mechanisms and they can be potential candidates for phytoextraction of P from the soil P enriched areas.

The combined effect of root morphological and resistance traits alleviated the growth limitations of Pinus massoniana seedlings under low phosphorus conditions

The combined effect of root morphological and resistance traits alleviated the growth limitations of Pinus massoniana seedlings under low phosphorus conditions

Domestication of rice may have changed its arbuscular mycorrhizal properties by modifying phosphorus nutrition-related traits and decreasing symbiotic compatibility.

Modern cultivated rice (Oryza sativa) typically experiences limited growth benefits from arbuscular mycorrhizal (AM) symbiosis. This could be due to the long-term domestication of rice under favorable phosphorus conditions. However, there is limited understanding of whether and how the rice domestication has modified AM properties. This study compared AM properties between a collection of wild (Oryza rufipogon) and domesticated rice genotypes and investigated the mechanisms underlying their differences by analyzing physiological, genomic, transcriptomic, and metabolomic traits critical for AM symbiosis. The results revealed significantly lower mycorrhizal growth responses and colonization intensity in domesticated rice compared to wild rice, and this change of AM properties may be associated with the domestication modifications of plant phosphorus utilization efficiency at physiological and genomic levels. Domestication also resulted in a decrease in the activity of the mycorrhizal phosphorus acquisition pathway, which may be attributed to reduced mycorrhizal compatibility of rice roots by enhancing defense responses like root lignification and reducing carbon supply to AM fungi. In conclusion, rice domestication may have changed its AM properties by modifying P nutrition-related traits and reducing symbiotic compatibility. This study offers new insights for improving AM properties in future rice breeding programs to enhance sustainable agricultural production.

Not only phosphorus: dauciform roots can also influence aboveground biomass through root morphological traits and metal cation concentrations

BackgroundPhosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear.MethodsA greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days.Results(1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots’ promotion of aboveground biomass accumulation.ConclusionDespite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions.

Strigolactones shape the assembly of root-associated microbiota in response to phosphorus availability.

Plants rely on strigolactones (SLs) to regulate their development and form symbiotic relationships with microbes as part of the adaptive phosphorus (P) efficiency strategies. However, the impact of SLs on root-associated microbial communities in response to P availability remains unknown. Here, root microbiota of SL biosynthesis (max3-11) and perception (d14-1) were compared to wild-type Col-0 plants under different P concentrations. Using high-throughput sequencing, the relationship between SLs, P concentrations, and the root-associated microbiota was investigated to reveal the variation in microbial diversity, composition, and interaction. Plant genotypes and P availability played important but different roles in shaping the root-associated microbial community. Importantly, SLs were found to attract Acinetobacter in low P conditions, which included an isolated CP-2 (Acinetobacter soli) that could promote plant growth in cocultivation experiments. Moreover, SLs could change the topologic structure within co-occurrence networks and increase the number of keystone taxa (e.g., Rhizobiaceae and Acidobacteriaceae) to enhance microbial community stability. This study reveals the key role of SLs in mediating root-associated microbiota interactions.IMPORTANCEStrigolactones (SLs) play a crucial role in plant development and their symbiotic relationships with microbes, particularly in adapting to phosphorus levels. Using high-throughput sequencing, we compared the root microbiota of plants with SL biosynthesis and perception mutants to wild-type plants under different phosphorus concentrations. These results found that SLs can attract beneficial microbes in low phosphorus conditions to enhance plant growth. Additionally, SLs affect microbial network structures, increasing the stability of microbial communities. This study highlights the key role of SLs in shaping root-associated microbial interactions, especially in response to phosphorus availability.

Arbuscular mycorrhizal fungi and Streptomyces: brothers in arms to shape the structure and function of the hyphosphere microbiome in the early stage of interaction

BackgroundFungi and bacteria coexist in a wide variety of environments, and their interactions are now recognized as the norm in most agroecosystems. These microbial communities harbor keystone taxa, which facilitate connectivity between fungal and bacterial communities, influencing their composition and functions. The roots of most plants are associated with arbuscular mycorrhizal (AM) fungi, which develop dense networks of hyphae in the soil. The surface of these hyphae (called the hyphosphere) is the region where multiple interactions with microbial communities can occur, e.g., exchanging or responding to each other’s metabolites. However, the presence and importance of keystone taxa in the AM fungal hyphosphere remain largely unknown.ResultsHere, we used in vitro and pot cultivation systems of AM fungi to investigate whether certain keystone bacteria were able to shape the microbial communities growing in the hyphosphere and potentially improved the fitness of the AM fungal host. Based on various AM fungi, soil leachates, and synthetic microbial communities, we found that under organic phosphorus (P) conditions, AM fungi could selectively recruit bacteria that enhanced their P nutrition and competed with less P-mobilizing bacteria. Specifically, we observed a privileged interaction between the isolate Streptomyces sp. D1 and AM fungi of the genus Rhizophagus, where (1) the carbon compounds exuded by the fungus were acquired by the bacterium which could mineralize organic P and (2) the in vitro culturable bacterial community residing on the surface of hyphae was in part regulated by Streptomyces sp. D1, primarily by inhibiting the bacteria with weak P-mineralizing ability, thereby enhancing AM fungi to acquire P.ConclusionsThis work highlights the multi-functionality of the keystone bacteria Streptomyces sp. D1 in fungal-bacteria and bacterial-bacterial interactions at the hyphal surface of AM fungi.3XiVYVBxkNucerLC-WX6ofVideo

Dependence of evolution of Cyanobacteria superiority on temperature and nutrient use efficiency in a meso-eutrophic plateau lake

Algal blooms in lakes have been a challenging environmental issue globally under the dual influence of human activity and climate change. Considerable progress has been made in the study of phytoplankton dynamics in lakes; The long-term in situ evolution of dominant bloom-forming cyanobacteria in meso-eutrophic plateau lakes, however, lacks systematic research. Here, the monthly parameters from 12 sampling sites during the period of 1997–2022 were utilized to investigate the underlying mechanisms driving the superiority of bloom-forming cyanobacteria in Erhai, a representative meso-eutrophic plateau lake. The findings indicate that global warming will intensify the risk of cynaobacteria blooms, prolong Microcystis blooms in autumn to winter or even into the following year, and increase the superiority of filamentous Planktothrix and Cylindrospermum in summer and autumn. High RUETN (1.52 Biomass/TN, 0.95–3.04 times higher than other species) under N limitation (TN < 0.5 mg/L, TN/TP < 22.6) in the meso-eutrophic Lake Erhai facilitates the superiority of Dolichospermum. High RUETP (43.8 Biomass/TP, 2.1–10.2 times higher than others) in TP of 0.03–0.05 mg/L promotes the superiority of Planktothrix and Cylindrospermum. We provided a novel insight into the formation of Planktothrix and Cylindrospermum superiority in meso-eutrophic plateau lake with low TP (0.005–0.07 mg/L), which is mainly influenced by warming, high RUETP and their vertical migration characteristics. Therefore, we posit that although the obvious improvement of lake water quality is not directly proportional to the control efficacy of cyanobacterial blooms, the evolutionary shift in cyanobacteria population structure from Microcystis, which thrives under high nitrogen and phosphorus conditions, to filamentous cyanobacteria adapted to low nitrogen and phosphorus levels may serve as a significant indicator of water quality amelioration. Therefore, we suggest that the risk of filamentous cyanobacteria blooms in the meso-eutrophic plateau lake should be given attention, particularly in light of improving water quality and global warming, to ensure drinking water safety.

Genetic Variability Analysis for Yield and Its Attributing Traits in Rice (Oryza Sativa L.) under Phosphorus-sufficient and Deficient Field Conditions

Aim: The present study aims to identify phosphorus deficiency tolerant rice genotypes under both phosphorus-sufficient and deficient conditions. Materials and Methods: Two kinds of fields (high and low phosphorus content) were selected based on their soil phosphorus availability. Hundred diverse rice germplasm was collected and planted in an augmented design along with four local checks namely, Swarna sub-1, MTU 1153, MTU 7029 and Uttar Sona. The data was recorded for 14 traits and subjected to different types of variability analysis. Place and Season of Study: The experiment took place at instructional Farm of Uttar Banga Krishi Vishwavidyalaya, Cooch Behar, West Bengal, India during the Kharif season of 2021. Results: The variability analysis revealed that phosphorus uptake showed a high genotypic coefficient of variation (GCV) under phosphorus-deficient condition and high phenotypic coefficient of variation (PCV) under both conditions. Grain yield showed high GCV and PCV under both the phosphorus conditions. Heritability was moderate whereas high Genetic advance as percentage of mean was observed under both the conditions for both phosphorus uptake and grain yield. Strong positive correlations were observed between days to flowering and various yield-related traits under both the conditions. Positive correlation was observed between phosphorus uptake and grain yield under phosphorus-sufficient condition, but a weaker correlation under phosphorus-deficient condition.

Adaptation Strategies of Seedling Root Response to Nitrogen and Phosphorus Addition.

The escalation of global nitrogen deposition levels has heightened the inhibitory impact of phosphorus limitation on plant growth in subtropical forests. Plant roots area particularly sensitive tissue to nitrogen and phosphorus elements. Changes in the morphological characteristics of plant roots signify alterations in adaptive strategies. However, our understanding of resource-use strategies of roots in this environment remains limited. In this study, we conducted a 10-month experiment at the Castanopsis kawakamii Nature Reserve to evaluate the response of traits of seedling roots (such as specific root length, average diameter, nitrogen content, and phosphorus content) to nitrogen and phosphorus addition. The aim was to reveal the adaptation strategies of roots in different nitrogen and phosphorus addition concentrations. The results showed that: (1) The single phosphorus and nitrogen-phosphorus interaction addition increased the specific root length, surface area, and root phosphorus content. In addition, single nitrogen addition promotes an increase in the average root diameter. (2) Non-nitrogen phosphorus addition and single nitrogen addition tended to adopt a conservative resource-use strategy to maintain growth under low phosphorus conditions. (3) Under the single phosphorus addition and interactive addition of phosphorus and nitrogen, the roots adopted an acquisitive resource-use strategy to obtain more available phosphorus resources. Accordingly, the adaptation strategy of seedling roots can be regulated by adding appropriate concentrations of nitrogen or phosphorus, thereby promoting the natural regeneration of subtropical forests.

Nutrient Variations and Their Use Efficiency of Pinus massoniana Seedling Tissues in Response to Low Phosphorus Conditions

Investigating the mechanisms by which plants adapt to low phosphorus content in ecosystems is crucial for nutrient dynamics division. Our study investigated the growth adaptation strategies of Pinus massoniana seedlings to low phosphorus conditions, including nutrient and non-structural carbohydrate (NSC) allocation, nutrient stoichiometry, and changes in nutrient resorption efficiency along a fact-based gradient. Our results showed that the total biomass and aboveground biomass proportion increased with substrate phosphorus content, reaching maximum biomass in the one-time phosphorus treatment. The nutrient concentration of components remained relatively stable, with the allocating preference to roots and needles under low phosphorus conditions. NSC was allocated as starch in fine roots and as soluble sugar in needles. Seedlings did not show signs of phosphorus limitation, even in the non-phosphorus group. The nitrogen resorption efficiency to phosphorus resorption efficiency ratio (NRE: PRE) of needles significantly varied between the high and low phosphorus treatments. In response to phosphorus deficiency, seedlings demonstrated homeostatic adjustments to maintain the relative stability of nutrient concentration. Fine roots and needles were prioritized to ensure nutrient uptake and photosynthetic product production. Additionally, it was necessary to differentiate the indicative function of nitrogen/phosphorus for various species and components, and NRE: PRE potentially provides a sensitive indicator of nutrient limitation status.

Bacterial community changes in the presence of AMF in the context of maize with low phosphorus content

PurposeArbuscular mycorrhizal fungi (AMF) perform an ancestral and essential association with plant roots, where plants provide carbohydrates and lipids, and the fungi respond by translocating water and nutrients to the roots through the hyphae. There is a need to investigate the microbial community associated with the rhizosphere of mycorrhizal plants in response to the multiple benefits (e.g., improved nutrition and stress resistance) provided by the association. In this work, we analyzed the bacterial communities associated with the rhizosphere of plants and their response to mycorrhizae in low P conditions.MethodsFor this purpose, inoculated and non-inoculated B73 corn plants were grown with a consortium of mycorrhizal fungi under low phosphorus conditions. Mycorrhiza response in B73 and the interaction with rhizosphere microbiome were characterized by sequencing the bacterial 16S rRNA gene.ResultsInoculated plants showed increased greater growth in leaf and root parameters in low P conditions. Bacterial microbiome showed changes in beta diversity and some OUTs significantly regulated by AMF presence.ConclusionThese data confirm the importance of mycorrhizae in phosphorus stress and rhizosphere community changes as a possible mechanism to improve plant growth.