Alterations In Root Morphology Research Articles

Assessing Lettuce Exposure to a Multipharmaceutical Mixture under Hydroponic Conditions: Findings through LC-ESI-TQ Analysis and Ecotoxicological Assessments.

The escalating global water scarcity demands innovative solutions, one of which is hydroponic vegetable cultivation systems that increasingly use reclaimed wastewater. Nevertheless, even treated wastewater may still harbor various emerging organic contaminants, including pharmaceuticals. This study aimed to comprehensively assess the impact of pharmaceuticals, focusing on bioconcentration factors (BCFs), translocation factors (TFs), pharmaceutical persistence in aqueous environment, ecotoxicological end points, and associated environmental and health risks. Lettuce (Lactuca sativa) was cultivated hydroponically throughout its entire growth cycle, exposed to seven distinct concentration levels of contaminants ranging from 0 to 500 μg·L-1 over a 35-day period. The findings revealed a diverse range of BCFs (2.3 to 880 L·kg-1) and TFs (0.019-1.48), suggesting a high potential of pharmaceutical uptake and translocation by L. sativa. The degradation of 20 pharmaceuticals within the water-lettuce system followed first-order degradation kinetics. Substantial ecotoxicological effects on L. sativa were observed, including increased mortality, alterations in root morphology and length, and changes in biomass weight (p < 0.05). Furthermore, the estimated daily intake of pharmaceuticals through L. sativa consumption suggested considerable health risks, even if lettuce would be one of the many vegetables consumed. It is hypothetical, as the values were calculated. Moreover, this study assessed the environmental risk associated with the emergence of antimicrobial resistance (AMR) in aquatic environments, revealing a significantly high risk of AMR emergence. In conclusion, these findings emphasize the multifaceted challenges posed by pharmaceutical contamination in aquatic environments and the necessity of proactive measures to mitigate associated risks to both environmental and human health.

Melatonin Modulates Tomato Root Morphology by Regulating Key Genes and Endogenous Hormones

Melatonin plays a vital role in plant growth and development. In this study, we treated hydroponically grown tomato roots with various concentrations of exogenous melatonin (0, 10, 30, and 50 μmol·L−1). We utilized root scanning and microscopy to examine alterations in root morphology and cell differentiation and elucidated the mechanism by which melatonin regulates these changes through the interplay with endogenous hormones and relevant genes. The results showed that for melatonin at concentrations ranging between 10 and 30 μmol·L−1, the development of lateral roots were significantly stimulated, the root hair growth was enhanced, and biomass accumulation and root activity were increased. Furthermore, we elucidated that melatonin acts as a mediator for the expression of genes, such as SlCDKA1, SlCYCA3;1, SlARF2, SlF3H, and SlKT1, which are involved in the regulation of root morphology changes. Additionally, we observed that melatonin influences the levels of endogenous hormones, including ZT, GA3, IAA, ABA, and BR, which subsequently impact the root morphology development of tomato roots. In summary, this study shows that tomato root morphology can be promoted by the optimal concentration of exogenous melatonin (10–30 μmol·L−1).

A virus induces alterations in root morphology while exerting minimal effects on the rhizosphere and endosphere microorganisms in rice.

The highly destructive southern rice black-streaked dwarf virus (SRBSDV) causes significant losses in rice production. To understand its impact on rice root, we studied fibrous root development and root microbiota variation (rhizosphere and endosphere) after SRBSDV infection. SRBSDV infection reduced the number and length of fibrous roots in rice. Interestingly, the rhizosphere had higher bacterial diversity and abundance at the initial (0 days) and 30-day postinfection stages, while 30-day-old roots showed increased diversity and abundance. However, there were no significant differences in microbiota diversity between infected and noninfected rice plants. The major rhizosphere microbiota included Proteobacteria, Bacteroidota, Acidobacteriota, and Planctomycetota, comprising about 80% of the community. The endosphere was dominated by Proteobacteria and Cyanobacteria, constituting over 90%, with Bacteroidota as the next most prominent group. Further, we identified differentially expressed genes related to plant-pathogen interactions, plant hormone signal, and ABC transporters, potentially affecting root morphology. Notably, specific bacteria (e.g. Inquilinus and Actinoplanes) showed correlations with these pathways. In conclusion, SRBSDV primarily influences root growth through host metabolism, rather than exerting direct effects on the root microbiota. These insights into the interactions among the pathogen, rice plant, and associated microbiota could have implications for managing SRBSDV's detrimental effects on rice production.

Phyto-oxylipin mediated plant immune response to colonization and infection in the soybean-Phytophthora sojae pathosystem.

Food security is a major challenge to sustainably supply food to meet the demands of the ever-growing global population. Crop loss due to pathogens is a major concern to overcoming this global food security challenge. Soybean root and stem rot caused by Phytophthora sojae results in approximately 20B $US crop loss annually. Phyto-oxylipins are metabolites biosynthesized in the plants by oxidative transformation of polyunsaturated fatty acids through an array of diverging metabolic pathways and play an important role in plant development and defense against pathogen colonization and infection. Lipid mediated plant immunity is a very attractive target for developing long term resistance in many plants' disease pathosystem. However, little is known about the phyto-oxylipin's role in the successful strategies used by tolerant soybean cultivar to mitigate Phytophthora sojae infection. We used scanning electron microscopy to observe the alterations in root morphology and a targeted lipidomics approach using high resolution accurate mass tandem mass spectrometry to assess phyto-oxylipin anabolism at 48h, 72h and 96h post infection. We observed the presence of biogenic crystals and reinforced epidermal walls in the tolerant cultivar suggesting a mechanism for disease tolerance when compared with susceptible cultivar. Similarly, the unequivocally unique biomarkers implicated in oxylipin mediated plant immunity [10(E),12(Z)-13S-hydroxy-9(Z),11(E),15(Z)-octadecatrienoic acid, (Z)-12,13-dihydroxyoctadec-9-enoic acid, (9Z,11E)-13-Oxo-9,11-octadecadienoic acid, 15(Z)-9-oxo-octadecatrienoic acid, 10(E),12(E)-9-hydroperoxyoctadeca-10,12-dienoic acid, 12-oxophytodienoic acid and (12Z,15Z)-9, 10-dihydroxyoctadeca-12,15-dienoic acid] generated from intact oxidized lipid precursors were upregulated in tolerant soybean cultivar while downregulated in infected susceptible cultivar relative to non-inoculated controls at 48h, 72h and 96h post infection by Phytophthora sojae, suggesting that these molecules may be a critical component of the defense strategies used in tolerant cultivar against Phytophthora sojae infection. Interestingly, microbial originated oxylipins, 12S-hydroperoxy-5(Z),8(Z),10(E),14(Z)-eicosatetraenoic acid and (4Z,7Z,10Z,13Z)-15-[3-[(Z)-pent-2-enyl]oxiran-2-yl]pentadeca-4,7,10,13-tetraenoic acid were upregulated only in infected susceptible cultivar but downregulated in infected tolerant cultivar. These microbial originated oxylipins are capable of modulating plant immune response to enhance virulence. This study demonstrated novel evidence for phyto-oxylipin metabolism in soybean cultivars during pathogen colonization and infection using the Phytophthora sojae-soybean pathosystem. This evidence may have potential applications in further elucidation and resolution of the role of phyto-oxylipin anabolism in soybean tolerance to Phytophthora sojae colonization and infection.

Review of current medical literature on root resorption in orthodontics.

Root resorption is a common iatrogenic consequence of orthodontic treatment, although it can also be seen in the absence of orthodontic treatment. It may occur at any time during orthodontic treatment and compromise prognosis of the tooth involved and also the stability of treatment results. Orthodontics is the only branch which actually uses the inflammatory process as a tool for solving esthetic and functional problems. Therefore, every orthodontist should know the risk factors of root resorption involved in the process and plan treatment with an aim to reduce its possibility. The severity and degree of root resorption related with orthodontic treatment are multifactorial, involving environmental factors and host factors. A proper medical history, an assessment of predisposing factors, radiographic evaluation of alterations in root morphology and careful planning and execution of orthodontic mechanics may reduce the incidence of root resorption. The current review is aimed at providing clinicians and academics with an insight into the mechanical and biological aspects in the process of root resorption, the methods of identification during its early stages and intervention at the right time to reduce its severity.

Effect of Zinc Priming on Salt Response of Wheat Seedlings: Relieving or Worsening?

In an attempt to alleviate salt-induced damage, the application of ZnO nanoparticles has been suggested. As the use of these particles has also been associated with phytotoxicity, to better clarify the effect of zinc and its possible mitigation of salt stress, we treated wheat seedlings with ZnO (nanoparticles or their bulk-scale counterparts, amended either in the growth medium, NPs and B, or sprayed on the leaves, SPNPs and SPB) with or without subsequent treatment with salt. Growth, photosynthetic parameters, zinc and ion concentration, and in situ and biochemical determination of oxidative stress in wheat leaves and/or in roots were considered. Both Zn and NaCl significantly inhibited growth and induced severe alterations in root morphology. Oxidative stress and damage decreased or increased under ZnO treatment and in saline conditions depending on the organ and on the size and mode of application of particles. In spite of the higher stress conditions often recorded in treated leaves, neither pigment concentration nor photochemical efficiency were decreased. A large variability in the effects of ZnO treatment/priming on seedling salt response was recorded; however, the presence of a cumulative negative effect of priming and salt stress sometimes observed calls for caution in the use of ZnO in protection from saline stress.

Phytotoxicity, Morphological, and Metabolic Effects of the Sesquiterpenoid Nerolidol on Arabidopsis thaliana Seedling Roots.

Natural herbicides that are based on allelopathy of compounds, can offer effective alternatives to chemical herbicides towards sustainable agricultural practices. Nerolidol, a sesquiterpenoid alcohol synthesized by many plant families, was shown to be the most effective allelopathic compound in a preliminary screening performed with several other sesquiterpenoids. In the present study, Arabidopsis thaliana seedlings were treated for 14 d with various cis-nerolidol concentrations (0, 50, 100, 200, 400, and 800 µM) to investigate its effects on root growth and morphology. To probe the underlying changes in root metabolome, we conducted untargeted gas chromatography mass spectrometry (GC-MS) based metabolomics to find out the specificity or multi-target action of this sesquiterpenoid alcohol. Oxidative stress (measured as levels of H2O2 and malondialdehyde (MDA) by-product) and antioxidant enzyme activities, i.e., superoxide dismutase (SOD) and catalase (CAT) were also evaluated in the roots. Nerolidol showed an IC50 (120 µM), which can be considered low for natural products. Nerolidol caused alterations in root morphology, brought changes in auxin balance, induced changes in sugar, amino acid, and carboxylic acid profiles, and increased the levels of H2O2 and MDA in root tissues in a dose-dependent manner. Several metabolomic-scale changes induced by nerolidol support the multi-target action of nerolidol, which is a positive feature for a botanical herbicide. Though it warrants further mechanistic investigation, nerolidol is a promising compound for developing a new natural herbicide.

Black pepper (Piper nigrum L.) associated endophytic Pseudomonas putida BP25 alters root phenotype and induces defense in rice (Oryza sativa L.) against blast disease incited by Magnaporthe oryzae

Blast disease caused by Magnaporthe oryzae is an important production constraint in rice farming worldwide. Novel strategies are needed to combat blast disease as the current options like host resistance and fungicides are either unstable or not-acceptable. Black pepper associated Pseudomonas putida BP25 endogenously colonized rice -a monocot, in a density-dependent manner with altered root growth and defense activation, also showed biocontrol activity against blast caused by M. oryzae. Fluorescence imaging of P. putida BP25 primed seedlings revealed extensive bacterial colonization in roots that was further confirmed in plate assay and qPCR. Although initial counts could be correlated with bacterial dose used for priming, the bacterial population stabilized 14-days post priming suggesting internal regulation of endophyte colonization. Endophytic colonization of rice triggered alteration in root morphology, possibly, due trade-off between growth and defense. P. putida BP25 significantly inhibited the mycelium of M. oryzae by both volatile and non-volatile metabolites and also seed priming protected the rice from blast. Activities of defense related peroxidase and phenols were found increased in primed plants. qPCR assay of rice defense and developmental genes indicated increased expression of Systemic Acquired Resistance (SAR) related OsPR1-1 (Pathogenesis Related protein 1-1) and down-regulation of OsPR3. In addition, rice seedlings emerged from endophyte priming showed down-regulation of stress responsive OsACO4 and OsACS6 involved in inter-nodal elongation which plays an important role in growth and development.

Potential of PM-selected components to induce oxidative stress and root system alteration in a plant model organism

Over the last years, various acellular assays have been used for the evaluation of the oxidative potential (OP) of particular matter (PM) to predict PM capacity to generate reactive oxygen (ROS) and nitrogen (RNS) species in biological systems. However, relationships among OP and PM toxicological effects on living organisms are still largely unknown. This study aims to assess the effects of atmospheric PM-selected components (brake dust - BD, pellet ash - PA, road dust - RD, certified urban dust NIST1648a - NIST, soil dust - S, coke dust - C and Saharan dust - SD) on the model plant A. thaliana development, with emphasis on their capacity to induce oxidative stress and root morphology alteration. Before growing A. thaliana in the presence of the PM-selected components, each atmospheric dust has been chemically characterized and tested for the OP through dithiothreitol (DTT), ascorbic acid (AA) and 2′,7′-dichlorofluorescin (DCFH) assays. After the exposure, element bioaccumulation in the A. thaliana seedlings, i.e., in roots and shoots, was determined and both morphological and oxidative stress analyses were performed in roots. The results indicated that, except for SD and S, all the tested dusts affected A. thaliana root system morphology, with the strongest effects in the presence of the highest OPs dusts (BD, PA and NIST). Principal component analysis (PCA) revealed correlations among OPs of the dusts, element bioaccumulation and root morphology alteration, identifying the most responsible dust-associated elements affecting the plant. Lastly, histochemical analyses of NO and O2− content and distribution confirmed that BD, PA and NIST induce oxidative stress in A. thaliana, reflecting the high OPs of these dusts and ultimately leading to cell membrane lipid peroxidation.

An Insight into the Ubiquity of Root Resorption in Orthodontics- A Review

Root resorption is a common iatrogenic consequence of orthodontic treatment, although it can also be seen in the absence of orthodontic treatment. It may occur at any time during orthodontic treatment and compromise prognosis of the tooth involved and also the stability of treatment results. Orthodontics is the only branch which actually uses the inflammatory process as a tool for solving esthetic and functional problems. Therefore, every orthodontist should know the risk factors of root resorption involved in the process and plan treatment with an aim to reduce its possibility. The severity and degree of root resorption related with orthodontic treatment are multifactorial, involving environmental factors and host factors. A proper medical history, an assessment of predisposing factors, radiographic evaluation of alterations in root morphology and careful planning and execution of orthodontic mechanics may reduce the incidence of root resorption. The current review is aimed at providing clinicians and academics with an insight into the mechanical and biological aspects in the process of root resorption, the methods of identification during its early stages and intervention at the right time to reduce its severity.

Recycling of wastes from fish beneficiation by composting: chemical characteristics of the compost and efficiency of their humic acids in stimulating the growth of lettuce.

Waste from the beneficiation of fish was composted with crushed grass aiming to characterize their chemical composition and investigate the possibility of the use of the final compost as source of humic acids (HA) able to stimulate the growth of lettuce. Compost presented pH value, C/N ratio, and electrical conductivity that allow its use as an organic fertilizer. The element content was present in the following order of abundance in the compost: P > Ca > N > Mg > K > Fe > Zn > Mn > Mo > Cu, and the humus composition was similar to that observed in others kind of organic residues composted. The high content of oxygen pointed out a high level of oxidation of HA, in line with the predominance of phenolic acidity in the functional groups. The 13C-NMR spectra showed marked resonances due to the presence of lipids and other materials resistant to degradation as methoxy substituent and N-alkyl groups. A concentration of 20mgL-1 HA increased significantly both dry and wet root matter in lettuce but the CO2 assimilation, stomatal conductance, and number of lateral roots of the plants were not affected. However, increases of 64% in the water-use efficiency was observed due to the HA addition, probably related to the root morphology alteration which resulted in 1.6-fold increase of lateral root average length and due to the higher H+ extrusion activity. Reuse of residues from the fish beneficiation activity by composting may represent a safe tool to increase the value of recycled organic residues and generate HA with potential use as plant growth stimulants.

Root Resorption with Orthodontic Mechanics: Pertinent Areas Revisited.

Root resorption can occur at any time during orthodontic treatment and lead to a compromise in the prognosis of the tooth and the stability of the treatment results. Recent research has focused more on the cause and effect relationship as well as preventive or treatment options to combat this unwelcome event. Investigations have highlighted the genetic as well as molecular aspects of the process and enabled clinicians to determine which patients might be susceptible. A proper medical history, an assessment of predisposing factors, a radiographic evaluation for alterations in root morphology and careful planning and execution of orthodontic mechanics may reduce the incidence of root resorption. The current review is aimed at providing clinicians and academics with an insight into the process of root resorption, the methods of identification during its early stages and intervention at the right time to reduce its severity.

Unraveling Root Developmental Programs Initiated by BeneficialPseudomonasspp. Bacteria

Plant roots are colonized by an immense number of microbes, referred to as the root microbiome. Selected strains of beneficial soil-borne bacteria can protect against abiotic stress and prime the plant immune system against a broad range of pathogens. Pseudomonas spp. rhizobacteria represent one of the most abundant genera of the root microbiome. Here, by employing a germ-free experimental system, we demonstrate the ability of selected Pseudomonas spp. strains to promote plant growth and drive developmental plasticity in the roots of Arabidopsis (Arabidopsis thaliana) by inhibiting primary root elongation and promoting lateral root and root hair formation. By studying cell type-specific developmental markers and employing genetic and pharmacological approaches, we demonstrate the crucial role of auxin signaling and transport in rhizobacteria-stimulated changes in the root system architecture of Arabidopsis. We further show that Pseudomonas spp.-elicited alterations in root morphology and rhizobacteria-mediated systemic immunity are mediated by distinct signaling pathways. This study sheds new light on the ability of soil-borne beneficial bacteria to interfere with postembryonic root developmental programs.

AM真菌在植物病虫害生物防治中的作用机制

丛枝菌根(Arbuscular Mycorrhizae,AM)真菌是一类广泛分布于土壤生态系统中的有益微生物,能与大约80%的陆生高等植物形成共生体。由土传病原物侵染引起的土传病害被植物病理学界认定为最难防治的病害之一。研究表明,AM真菌能够拮抗由真菌、线虫、细菌等病原体引起的土传性植物病害,诱导宿主植物增强对病虫害的耐/抗病性。当前,利用AM真菌开展病虫害的生物防治已经引起生态学家和植物病理学家的广泛关注。基于此,围绕AM真菌在植物病虫害生物防治中的最新研究进展,从AM真菌改变植物根系形态结构、调节次生代谢产物的合成、改善植物根际微环境、与病原微生物直接竞争入侵位点和营养分配、诱导植株体内抗病防御体系的形成等角度,探究AM真菌在植物病虫害防治中的作用机理,以期为利用AM真菌开展植物病虫害的生物防治提供理论依据,并对本领域未来的发展方向和应用前景进行展望。;Arbuscular mycorrhizal (AM) fungi are one of the widely spread micro-organisms, which could form symbionts with more than 80% of the vascular plants in natural ecosystems. It has been showed that AM symbionts could improve plant nutrients and water absorption; increase the resistance ability to stress conditions, thus AM fungi could enhance the host plant growth. The plant soil-borne diseases caused by soil-borne pathogens, including fungi, nematodes and bacteria, are considered as one of the most difficult controlling diseases in agriculture ecosystem. Previous studies have been demonstrated that AM symbionts could increase plant resistance to diseases, and to antagonize soil-borne pathogens. Thus, using AM fungi as a biological control method to antagonize soil-borne pathogens has received increasing interests by phytopathologists and ecologists. On the basis of this, the mechanisms of resistance to diseases induced by AM fungi were summarized in this paper. Mechanisms covered in this review include root morphology alteration, regulation of secondary metabolite production, improvement of rhizosphere environments, competition with pathogenic microorganisms on invasive sites and on nutrition distribution in host plants, and formation of defense systems in plants. Firstly, the characteristics of root morphology alterations were explained, including how AM fungi influence their structures and functions. Secondly, the regulation of AM fungi to secondary metabolites was illustrated. Several types of products, including phytoalexin, callose, alkaloid and phenols were reviewed. Thirdly, AM fungi could improve the rhizosphere environments by influence soil physical and chemical proprieties, and enhance the growth of other beneficial microorganism in rhizosphere soil. Fourth, AM fungi could compete with pathogenic microorganisms. The two kinds of microorganisms maybe compete for the same invasive sites in root systems, and thus they could regulate the nutrition distribution. Fifth, AM fungi could induced the host plant to form the defense systems in plants, including improvement the concentrations of phytohormone, induced the production of signal substrates, regulation of genes expression and enhanced the proteins production, thus AM fungi could enhance the resistance ability of host plant to pathogenic microorganisms. The aim of this paper was to enhance the potential use of AM fungi as a biological control method for preventing plant diseases in future.

Accumulation and Effects of Sulfadimethoxine in Salix Fragilis L. Plants: A Preliminary Study to Phytoremediation Purposes

The application of manure to fertilize arable lands is one of the major means through which veterinary sulfonamides (SAs) enter the environment. Little is known about the capacity of woody plants to phytoremediate this class of antibiotics. To this purpose we performed preliminary studies to evaluate Salix fragilis L. response to sulfadimethoxine (SDM) by investigating both its ability to absorb and tolerate doses of SDM found in fresh faeces of treated calves. Forty cuttings were exposed to either 0, 0.5, 1, or 2 mM of SDM for one month. Decreases in photosynthetic electron transport rate and net CO2 assimilation after 25 days for the higher SDM concentrations were noticed. Moreover, alterations in root morphology of treated plants were observed and further investigated through electron microscopy. However, collected data revealed high root accumulation potential. These preliminary results are promising as they demonstrate that Salix fragilis L. can both absorb and tolerate high concentrations of SAs.

Truffles regulate plant root morphogenesis via the production of auxin and ethylene.

Truffles are symbiotic fungi that form ectomycorrhizas with plant roots. Here we present evidence that at an early stage of the interaction, i.e. prior to physical contact, mycelia of the white truffle Tuber borchii and the black truffle Tuber melanopsorum induce alterations in root morphology of the host Cistus incanus and the nonhost Arabidopsis (Arabidopsis thaliana; i.e. primary root shortening, lateral root formation, root hair stimulation). This was most likely due to the production of indole-3-acetic acid (IAA) and ethylene by the mycelium. Application of a mixture of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid and IAA fully mimicked the root morphology induced by the mycelium for both host and nonhost plants. Application of the single hormones only partially mimicked it. Furthermore, primary root growth was not inhibited in the Arabidopsis auxin transport mutant aux1-7 by truffle metabolites while root branching was less effected in the ethylene-insensitive mutant ein2-LH. The double mutant aux1-7;ein2-LH displayed reduced sensitivity to fungus-induced primary root shortening and branching. In agreement with the signaling nature of truffle metabolites, increased expression of the auxin response reporter DR5GFP in Arabidopsis root meristems subjected to the mycelium could be observed, confirming that truffles modify the endogenous hormonal balance of plants. Last, we demonstrate that truffles synthesize ethylene from l-methionine probably through the alpha-keto-gamma-(methylthio)butyric acid pathway. Taken together, these results establish the central role of IAA and ethylene as signal molecules in truffle/plant interactions.