Root Cells Research Articles

Ionomic and proteomic changes highlight the effect of silicon supply on the nodules functioning of Trifolium incarnatum L.

IntroductionNumerous studies have reported the beneficial effects of silicon (Si) in alleviating biotic or abiotic stresses in many plant species. However, the role of Si in Fabaceae facing environmental stress is poorly documented. The aim of this study is to investigate the effect of Si on physiological traits and nodulation efficiency in Trifolium incarnatum L.MethodsSi was supplied (1.7 mM in the form of Na2SiO3) plants inoculated with Rhizobium leguminosarum bv trifolii and plant physiological traits and nodule ionomic and molecular traits were monitored over 25 days.ResultsSi supply promoted shoot biomass, the quantity of both Si and N in roots and shoots, and the number, biomass and density of nodules and their nitrogenase abundance which contribute to better dinitrogen (N2) fixation. Ionomic analysis of nodules revealed that Si supply increased the amount of several macroelements (potassium, phosphorus and sulfur) and microelements (copper, zinc and molybdenum) known to improve nodulation efficiency and N2 fixation. Finally, comparative proteomic analysis (+Si versus -Si) of nodules highlighted that Si modulated the proteome of both symbionts with 989 and 212 differentially accumulated proteins (DAPs) in the infected host root cells and their symbiont bacteria, respectively.DiscussionAmong the DAPs, the roles of those involved in nodulation and N2 fixation are discussed. For the first time, this study provides new insights into the effects of Si on both nodular partners and paves the way for a better understanding of the impact of Si on improving nodule function, and more specifically, on the nodules’ N2-fixing capacity.

ABI3 regulates ABI1 function to control cell length in primary root elongation zone.

Post-embryonic primary root growth is effectively an interplay of several hormone signalling pathways. Here, we show that the ABA-responsive transcription factor ABI3 controls primary root growth through the regulation of JA signalling molecule JAZ1 along with ABA-responsive factor ABI1. In the absence of ABI3, the primary root elongation zone is shortened with significantly reduced cell length. Expression analyses and ChIP-based assays indicate that ABI3 negatively regulates JAZ1 expression by occupying its upstream regulatory sequence and enriching repressive histone modification mark H3K27 trimethylation, thereby occluding RNAPII occupancy. Previous studies have shown that JAZ1 interacts with ABI1, the protein phosphatase 2C, that works during ABA signalling. Our results indicate that in the absence of ABI3, when JAZ1 expression levels are high, the ABI1 protein shows increased stability, compared to when JAZ1 is absent, or ABI3 is overexpressed. Consequently, in the abi3-6 mutant, due to the higher stability of ABI1, reduced phosphorylation of plasma membrane H+-ATPase (AHA2) occurs. HPTS staining further indicated that abi3-6 root cell apoplasts show reduced protonation, compared to wild-type and ABI3 overexpressing seedlings. Such impeded proton extrusion negatively affects cell length in the primary root elongation zone. ABI3 therefore controls cell elongation in the primary root by affecting the ABI1-dependent protonation of root cell apoplasts. In summary, ABI3 controls the expression of JAZ1 and in turn modulates the function of ABI1 to regulate cell length in the elongation zone during primary root growth.

Mn−Ce Symbiosis: Nanozymes with Multiple Active Sites Facilitate Scavenging of Reactive Oxygen Species (ROS) Based on Electron Transfer and Confinement Anchoring

AbstractRegulating appropriate valence states of metal active centers, such as Ce3+/Ce4+ and Mn3+/Mn2+, as well as surface vacancy defects, is crucial for enhancing the catalytic activity of cerium‐based and manganese‐based nanozymes. Drawing inspiration from the efficient substance exchange in rhizobia‐colonized root cells of legumes, we developed a symbiosis nanozyme system with rhizobia‐like CeOx nanoclusters robustly anchored onto root‐like Mn3O4 nanosupports (CeOx/Mn3O4). The process of “substance exchange” between Ce and Mn atoms—reminiscent of electron transfer—not only fine‐tunes the metal active sites to achieve optimal Ce3+/Ce4+ and Mn3+/Mn2+ ratios but also enhances the vacancy ratio through interface defect engineering. Additionally, the confinement anchoring of CeOx on Mn3O4 ensures efficient electron transfer in catalytic reactions. The final CeOx/Mn3O4 nanozyme demonstrates potent catalase‐like (CAT‐like) and superoxide dismutase‐like (SOD‐like) activities, excelling in both chemical settings and cellular environments with high reactive oxygen species (ROS) levels. This research not only unveils a novel material adept at effectively eliminating ROS but also presents an innovative approach for amplifying the efficacy of nanozymes.

Elucidating genetic variability between randomly bred domestic cats and Persian domestic cats from different geographical locations using microsatellite markers.

The domestic cat (Felis catus) is a newly evolved species in the family Felidae that has developed some great features among mammals. It is critical to conserve these species and prevent inbreeding from reducing their genetic diversity by understanding their genetic relationships and applying the information to breeding management. The diverse population was an excellent choice for studying genetic diversity and inbreeding phenomena. To conduct this research, 128 individuals from 8 populations, including Azerbaijan, Persian, Ahar, Uermia, Tehran, Karaj, Turkish and Shop cat (both genders), were randomly selected from different geographical regions. We selected eight STR markers with different chromosomal locations based on polymorphism and observed allele numbers in the next step. DNA extraction was performed using tail hair root, PCR and electrophoresis, and gel staining was performed according to routine laboratory protocol. For statistical analysis, CONVERT versions POPGENE, ARLEQUIN GenAlEx and R script analysis. Remarkably, our results showed that 23 alleles were identified in 128 samples. The highest number of alleles belonged to the FCa096 locus (eight alleles) in the Persian population, followed by FCa045 (seven alleles) in the Persian and Ahar populations. Another new finding is that the lowest number of alleles belonged to the 35 and FCa77 locus (two alleles). In addition, pairwise differentiation between and within populations was examined using the genetic distance index. Overall, the results showed that the degree of differentiation within the population is high in the Turkish population compared to other population groups and lower in the Azerbaijan population. In addition, principal component discriminant analysis-based analysis based on the ADAGENET package shows the distribution of samples by geographical location. The results show that genetic mixing between populations is high. On this basis, we conclude that randomly bred domestic cats have a higher level of diversity than Persian domestic cats. This is an interesting topic for future work.

Mechanisms by Which Increased pH Ameliorates Copper Excess in Citrus sinensis Roots: Insight from a Combined Analysis of Physiology, Transcriptome, and Metabolome

Limited data are available on copper (Cu)–pH interaction-responsive genes and/or metabolites in plant roots. Citrus sinensis seedlings were treated with 300 μM (Cu toxicity) or 0.5 μM (control) CuCl2 at pH 3.0 or 4.8 for 17 weeks. Thereafter, gene expression and metabolite profiles were obtained using RNA-Seq and widely targeted metabolome, respectively. Additionally, several related physiological parameters were measured in roots. The results indicated that elevating the pH decreased the toxic effects of Cu on the abundances of secondary metabolites and primary metabolites in roots. This difference was related to the following several factors: (a) elevating the pH increased the capacity of Cu-toxic roots to maintain Cu homeostasis by reducing Cu uptake and Cu translocation to young leaves; (b) elevating the pH alleviated Cu toxicity-triggered oxidative damage by decreasing reactive oxygen species (ROS) formation and free fatty acid abundances and increasing the ability to detoxify ROS and maintain cell redox homeostasis in roots; and (c) increasing the pH prevented root senescence and cell wall (CW) metabolism impairments caused by Cu toxicity by lowering Cu levels in roots and root CWs, thus improving root growth. There were some differences and similarities in Cu–pH interaction-responsive genes and metabolites between leaves and roots.

Host Recognition for Survival of Plant Pathogens

The intact, healthy plant is a community of cells built in a fortress-like fashion. Plant cells consist of cell wall contains the nucleus and various organelles and all the substances for which the pathogens attack them. The cytoplasm and the organelles it contains are separated from each other by membranes that carry various types of proteins embedded in them (Fig. 5-2). The plant surfaces that come in contact with the environment either consist of cellulose, as in the epidermal cells of roots and in the intercellular spaces of leaf parenchyma cells, or consist of a cuticle that covers the epidermal cell walls, as is the case in the aerial parts of plants. Often an additional layer, consisting of waxes, is deposited outside the cuticle, especially on younger parts of plants Pathogens attack plants because during their evolutionary development they have acquired the ability to live off the substances manufactured by the host plants, and some of the pathogens depend on these substances for survival. Many substances are contained in the protoplast of the plant cells, however, and if pathogens are to gain access to them they must first penetrate the outer barriers formed by the cuticle and/or cell walls. Even after the outer cell wall has been penetrated, further invasion of the plant by the pathogen necessitates the penetration of more cell walls. Furthermore, the plant cell contents are not always found in forms immediately utilizable by the pathogen and must be broken down to units that the pathogen can absorb and assimilate. Moreover, the plant, reacting to the presence and activities of the pathogen, produces structures and chemical substances that interfere with the advance or the existence of the pathogen; if the pathogen is to survive and to continue living off the plant, it must be able to overcome such obstacles. Therefore, for a pathogen to infect a plant it must be able to make its way into and through the plant, obtain nutrients from the plant, and neutral

A novel root hair mutant, srh1, affects root hair elongation and reactive oxygen species levels in wheat

BackgroundRoot hairs are single-celled projections on root surfaces, critical for water and nutrient uptake. Here, we describe the first short root hair mutant in wheat (Triticum aestivum L.), identified in a mutagenized population and termed here short root hair 1 (srh1).ResultsWhile the srh1 mutant can initiate root hair bulges, lack of subsequent extension results in very short root hairs. Due to its semi-dominant nature, heterozygous lines displayed intermediate root hair lengths compared to wild-type. Bulked segregant analysis in a BC1F3 segregating population genotyped via exome capture sequencing localized the genetic control of this mutant to a region on the long arm of chromosome 3A. Via RNA sequencing and bioinformatic analysis, we identified two promising candidate genes. The first was a respiratory burst oxidase homolog (RBOH) encoding gene TaNOX3-A, orthologous to RBOH genes controlling root hair elongation in rice (OsNOX3) and maize (ZmRTH5), that carries a missense mutation in a conserved region of the predicted protein. RBOHs are membrane bound proteins that produce reactive oxygen species (ROS) which trigger cell wall extensibility, allowing subsequent root hair elongation. Notably, reduced ROS levels were observed in srh1 root hair bulges compared to wild-type. The second candidate was the calreticulin-3 encoding gene TaCRT3-A, located within the wider srh1 interval and whose expression was significantly downregulated in srh1 root tissues.ConclusionsThe identification of a major effect gene controlling wheat root hair morphology provides an entry point for future optimization of root hair architecture best suited to future agricultural environments.

The MON1-CCZ1 complex plays dual roles in autophagic degradation and vacuolar protein transport in rice.

Autophagy is a highly conserved cellular program in eukaryotic cells which mediates the degradation of cytoplasmic components through the lysosome, also named the vacuole in plants. However, the molecular mechanisms underlying the fusion of autophagosomes with the vacuole remain unclear. Here, we report the functional characterization of a rice (Oryza sativa) mutant with defects in storage protein transport in endosperm cells and accumulation of numerous autophagosomes in root cells. Cytological and immunocytochemical experiments showed that this mutant exhibits a defect in the fusion between autophagosomes and vacuoles. The mutant harbors a loss-of-function mutation in the rice homolog of Arabidopsis thaliana MONENSIN SENSITIVITY1 (MON1). Biochemical and genetic evidence revealed a synergistic interaction between rice MON1 and AUTOPHAGY-RELATED 8a in maintaining normal growth and development. In addition, the rice mon1 mutant disrupted storage protein sorting to protein storage vacuoles. Furthermore, quantitative proteomics verified that the loss of MON1 function influenced diverse biological pathways including autophagy and vacuolar transport, thus decreasing the transport of autophagic and vacuolar cargoes to vacuoles. Together, our findings establish a molecular link between autophagy and vacuolar protein transport, and offer insights into the dual functions of the MON1-CCZ1 (CAFFEINE ZINC SENSITIVITY1) complex in plants.

Transcriptome Analysis of Chinese Cabbage Infected with Plasmodiophora Brassicae in the Primary Stage

Clubroot disease caused by the infection of Plasmodiophora brassicae is widespread in China, and significantly reduces the yield of Chinese cabbage (Brassica rapa L. ssp. pekinensis). However, the resistance mechanism of Chinese cabbage against clubroot disease is still unclear. It is important to exploit the key genes that response to early infection of P. brassicae. In this study, it was found that zoospores were firstly invaded hair roots on the 8th day after inoculating with 1 × 107 spores/mL P. brassicae. Transcriptome analysis found that the early interaction between Chinese cabbage and P. brassicae caused the significant expression change of some defense genes, such as NBS-LRRs and pathogenesis-related genes, etc. The above results were verified by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Otherwise, peroxidase (POD) salicylic acid (SA) and jasmonic acid (JA) were also found to be important signal molecules in the resistance to clubroot disease in Chinese cabbage. This study provides important clues for understanding the resistance mechanism of Chinese cabbage against clubroot disease.

Immunolocalization and Ultrastructure Show Ingestion of Cry Protein Expressed in Glycine max by Heterodera glycines and Its Mode of Action.

Great interest exists in developing a transgenic trait that controls the economically important soybean (Glycine max) pest, soybean cyst nematode (SCN, Heterodera glycines), due to its adaptation to native resistance. Soybean plants expressing the Bacillus thuringiensis delta-endotoxin, Cry14Ab, were recently demonstrated to control SCN in both growth chamber and field testing. In that communication, ingestion of the Cry14Ab toxin by SCN second stage juveniles (J2s) was demonstrated using fluorescently labeled Cry14Ab in an in vitro assay. Here, we show that consistent with expectations for a Cry toxin, Cry14Ab has a mode of action unique from the native resistance sources Peking and PI 88788. Further, we demonstrate in planta the ingestion and localization of the Cry14Ab toxin in the midgut of nematodes feeding on roots expressing Cry14Ab using immunogold labeling and transmission electron microscopy. We observed immunolocalization of the toxin and resulting intestinal damage primarily in the microvillus-like structure (MvL)-containing region of the midgut intestine but not in nematodes feeding on roots lacking toxin. This demonstrated that Cry14Ab was taken up by the J2 SCN, presumably through the feeding tube within the plant root cell that serves as its feeding site. This suggests that relatively large proteins can be taken up through the feeding tube. Electron microscopy showed that Cry14Ab caused lysis of the midgut MvL membrane and eventual degradation of the MvL and the lysate, forming particulate aggregates. The accumulated electron-dense aggregate in the posterior midgut intestine was not observed in SCN in nonCry14Ab-expressing plants. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Effects of cinnamic acid on the root growth of cucumber (cucumis sativus l.) and figleaf ground (cucurbita ficifolia bouché) seedlings

Effect of cinnamic acid (CA) on growth and endogenous hormone content in the roots of cucumber and figleaf gourd seedlings were studied and explained the reason why figleaf gourd was better in resisting CA stress than cucumber using their seedlings as experimental materials. The effect of CA at different concentrations (0, 0.05, 0.10, 0.15, 0.20 and 0.25 mmol/l) was analysed on primary root elongation, total root elongation, average diameter of total roots, total root volume, and total root tips as well as the effects of 0 and 0.25 mmol/l CA on root growth, root density, root hair growth rate, indole acetic acid (IAA) content and ethylene (ET) production rate. The results showed that CA stress decreased the primary root elongation, total root elongation, total root tips, Grade III root and root hair growth rates of both plants. The inhibiting effect of CA was stronger on cucumber than figleaf gourd. Besides, CA stress increased their average diameters of total roots and root hair densities. The increase in the average diameter of total roots of cucumber was larger than that of figleaf gourd while its increase in root hair density was far lower. Apart from that, 0.25 mmol/l CA stress increased the IAA contents and ET production rates in both kinds of roots. The increase in IAA content in cucumber root was 16% higher than in figleaf gourd. However, the increase in the ET production rate of cucumber root was 51% lower than figleaf gourd root. In conclusion, higher concentration IAA could inhibit root growth. Under CA stress, the increase in the IAA content in figleaf gourd root was lower than that in cucumber root, indicating that CA exerted a weaker inhibiting influence on figleaf gourd. Besides, higher ET production rate contributed to the increase in root hair density. Under CA stress, figleaf gourd root had a higher ET production rate than cucumber root, thus having more root hairs. Bangladesh J. Bot. 53(3): 703-710, 2024 (September) Special

Rhizosheath Formation and Its Role in Plant Adaptation to Abiotic Stress

The rhizosheath, the layer of soil tightly attached to the roots, protects plants against abiotic stress and other adverse conditions by providing a bridge from the plant root system to the soil. It reduces the formation of air gaps between the root and soil and facilitates the transportation of water at the root–soil interface. It also serves as a favourable niche for plant-growth-promoting rhizobacteria in the surrounding soil, which facilitate the absorption of soil water and nutrients. This review compares the difference between the rhizosheath and rhizosphere, and summarises the molecular and physiological mechanisms of rhizosheath formation, and identifying the causes of rhizosheath formation/non-formation in plants. We summarise the chemical and physical factors (root hair, soil-related factors, root exudates, and microorganisms) that determine rhizosheath formation, and focus on the important functions of the rhizosheath in plants under abiotic stress, especially in drought stress, phosphorus deficiency, aluminium stress, and salinity stress. Understanding the roles played by the rhizosheath and the mechanisms of its formation provides new perspectives for improving plant stress tolerance in the field, which will mitigate the increasing environmental stress conditions associated with on-going global climate change.

Physiological and biochemical responses in a cadmium accumulator of traditional Chinese medicine Ligusticum sinense cv. Chuanxiong under cadmium condition

Ligusticum sinense cv. Chuanxiong (L. Chuanxiong), one of the widely used traditional Chinese medicines (TCM), is currently facing the problem of excessive cadmium (Cd) content. This problem has significantly affected the quality and safety of L. Chuanxiong and become a vital factor restricting its clinical application and international trade development. Currently, to solve the problem of excessive Cd, it is essential to research the response mechanisms of L. Chuanxiong to Cd stress. However, there are few reports on its physiological and biochemical responses under Cd stress. In this study, we conducted the hydroponic experiment under 25 μM Cd stress, based on the Cd content of the genuine producing areas soil. The results showed that 25 μM Cd stress not only had no significant inhibitory effect on the growth of L. Chuanxiong seedlings but also significantly increased the chlorophyll a content (11.79%) and root activity (51.82%) compared with that of the control, which might be a hormesis effect. Further results showed that the absorption and assimilation of NH4+ increased in seedlings under 25 μM Cd stress, which was associated with high photosynthetic pigments. Here, we initially hypothesized and confirmed that Cd exceedance in the root system of L. Chuanxiong was due to the thickening of the root cell wall, changes in the content of the cell wall components, and chelation of Cd by GSH. There was an increase in cell wall thickness (57.64 %) and a significant increase in cellulose (25.48%) content of roots under 25 μM Cd stress. In addition, L. Chuanxiong reduced oxidative stress caused by 25 μM Cd stress mainly through the GSH/GSSG cycle. Among them, GSH-Px (48.26%) and GR (42.64%) activities were significantly increased, thereby maintaining a high GSH/GSSG ratio. This study preliminarily reveals the response of L. Chuanxiong to Cd stress and the mechanism of Cd enrichment. It provides a theoretical basis for solving the problem of Cd excessive in L. Chuanxiong.Graphical Physiological and biochemical mechanisms of L. Chuanxiong seedlings under Cd stress.

WRKY Transcription Factors in Response to Metal Stress in Plants: A Review.

Heavy metals in soil can inflict direct damage on plants growing within it, adversely affecting their growth height, root development, leaf area, and other physiological traits. To counteract the toxic impacts of heavy metals on plant growth and development, plants mitigate heavy metal stress through mechanisms such as metal chelation, vacuolar compartmentalization, regulation of transporters, and enhancement of antioxidant functions. WRKY transcription factors (TFs) play a crucial role in plant growth and development as well as in responses to both biotic and abiotic stresses; notably, heavy metal stress is classified as an abiotic stressor. An increasing number of studies have highlighted the significant role of WRKY proteins in regulating heavy metal stress across various levels. Upon the entry of heavy metal ions into plant root cells, the production of reactive oxygen species (ROS) is triggered, leading to the phosphorylation and activation of WRKY TFs through MAPK cascade signaling. Activated WRKY TFs then modulate various physiological processes by upregulating or downregulating the expression of downstream genes to confer heavy metal tolerance to plants. This review provides an overview of the research advancements regarding WRKY TFs in regulating heavy metal ion stress-including cadmium (Cd), arsenic (As), copper (Cu)-and aluminum (Al) toxicity.

High-affinity potassium transporter TaHAK1 implicates in cesium tolerance and phytoremediation

Cesium (Cs) is a toxic alkaline metal affecting human health. Plant high-affinity K transporters (HAKs) involved in Cs uptake and transport have been identified in several plants. However, the molecular regulatory mechanisms of Cs uptake and transport, and homeostasis between Cs and K by HAKs remain unknown. In this study, TaHAK1 was overexpressed in rice (TaHAK1-OEs) to evaluate Cs absorption capacity and the Cs and K homeostasis mechanisms. Results showed that TaHAK1 promoted seedling growth by fixing Cs in the root cell wall and modifying Cs distribution. Transcriptome and bioinformatics analyses revealed that 37,828 differentially expressed genes (DEGs) were significantly induced in TaHAK1-OEs, of which the pathways involved in cell wall biosynthesis and ion absorption transport were notably affected including genes, XTHs, CSLEs, HAKs, and ABCs. Moreover, under Cs-contaminated soil, TaHAK1-OEs exhibited improved Cs tolerance by decreasing Cs accumulation and increasing K content in different tissues, particularly in the grains, indicating that TaHAK1 acts as a candidate gene for screening genetic modification of Cs phytoremediation and developing low-Cs-accumulation rice varieties. This study provides new insights into the uptake and translocation of Cs and the homeostasis of Cs and K in plants, and also supplies new strategy to improve phytoremediation efficiency.

Fusarium sp. Strain K-23 Alleviates Salt Stress in Arabidopsis thaliana Through its Root Hair Growth-Promoting Effect

Fusarium sp. Strain K-23 Alleviates Salt Stress in Arabidopsis thaliana Through its Root Hair Growth-Promoting Effect

The effect of biochar amendment on Cd accumulation in Bidens pilosa L: Changing Cd subcellular distribution, cell wall polysaccharide Cd-binding capacity and composition

Biochar can reduce Cd uptake by plants, thereby reducing its biotoxicity, but the mechanisms involved at the subcellular level have not been thoroughly elucidated. In this work, we explored the effect of maize straw biochar on Cd accumulation by Bidens pilosa L. and its mechanism at subcellular levels. After 90 days of potting experiment, the subcellular fractions were extracted by differential centrifugation, and the polysaccharide fractions of root cell walls were extracted by leaching centrifugation, and then the Cd content of each fraction was determined. Results showed that Cd was preferentially distributed in cell walls of three organs. Additionally, biochar addition resulted in a greater distribution of Cd from cell wall to soluble fractions and organelles in stems. These results suggested that cell wall immobilization and intracellular compartmentalization were critical detoxification mechanisms tackling Cd stress with biochar addition of Bidens pilosa L. Pectin was the main sink where Cd was stored. And galacturonic acid content in pectin occupied the highest ratio among the three polysaccharide fractions. After biochar addition, in hemicellulose the change of Cd content was consistent with the change of galacturonic acid content. These results suggested that the galacturonic acid in hemicellulose played an important role in Cd binding. Biochar addition reduced the bioavailability of soil Cd and improved the growth environment, thus inducing Bidens pilosa L. to change the composition of root cell wall in response to Cd stress.

Impact nano- and micro- form of CdO on barley growth and oxidative stress response

The objective was investigated the effects of CdO and nano-CdO as potential toxic pollutants on growth and redox response of barley. CdO and nano-CdO have been found to cause significant phytotoxicity in barley seedlings, with nano-CdO increasing plant tissue cadmium accumulation. This accumulation is linked to growth retardation and oxidative stress. Low molecular weight antioxidants like restored glutathione and ascorbate have been found to increase the activity of glutathione peroxidase (GPX), glutathione-S-transferase (GSTs), and ascorbate peroxidase (APX) in green tissues. Catalase (CAT) activity increased from 50 % with 100 mg/l CdO to 70 % with 1000 mg/l and nano-CdO. The observed disturbance in redox balance signals the upregulation of corresponding genes. Antioxidant enzyme isoform gene transcripts increased for SODB, CAT2, and APX. Cadmium buildup in root cells causes oxidative stress, leading to upregulation of SOD, CAT, GR, and GSTs isoform genes as well as protein carbonylation, sulfhydryl group degradation, and MDA accumulation. CdO and nano-CdO have similar phytotoxic effects, but bioavailability affects biochemical and molecular responses.

Simultaneous mutations in ITPK4 and MRP5 genes result in a low phytic acid level without compromising salt tolerance in Arabidopsis.

Generation of crops with low phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6)) is an important breeding direction, but such plants often display less desirable agronomic traits. In this study, through ethyl methanesulfonate-mediated mutagenesis, we found that inositol 1,3,4-trisphosphate 5/6-kinase 4 (ITPK4), which is essential for producing InsP6, is a critical regulator of salt tolerance in Arabidopsis. Loss of function of ITPK4 gene leads to reduced root elongation under salt stress, which is primarily because of decreased root meristem length and reduced meristematic cell number. The itpk4 mutation also results in increased root hair density and increased accumulation of reactive oxygen species during salt exposure. RNA sequencing assay reveals that several auxin-responsive genes are down-regulated in the itpk4-1 mutant compared to the wild-type. Consistently, the itpk4-1 mutant exhibits a reduced auxin level in the root tip and displays compromised gravity response, indicating that ITPK4 is involved in the regulation of the auxin signaling pathway. Through suppressor screening, it was found that mutation of Multidrug Resistance Protein 5 (MRP5)5 gene, which encodes an ATP-binding cassette (ABC) transporter required for transporting InsP6 from the cytoplasm into the vacuole, fully rescues the salt hypersensitivity of the itpk4-1 mutant, but in the itpk4-1 mrp5 double mutant, InsP6 remains at a very low level. These results imply that InsP6 homeostasis rather than its overall amount is beneficial for stress tolerance in plants. Collectively, this study uncovers a pair of gene mutations that confer low InsP6 content without impacting stress tolerance, which offers a new strategy for creating "low-phytate" crops.

A novel fluorescent probe for viscosity and polarity detection in real tobacco root cells and biological imaging.

The disruption of lipid droplet function is associated with the pathogenesis of various diseases. Clarifying the response behavior of lipid droplets to the microenvironment at the cellular level is of great significance. Plant lipids not only exist in phospholipids in cell membranes, but also in aromatic essential oils. Monitoring the level of lipid droplets in plant cells using fluorescent probes provides a simple method for screening lipid-rich varieties. We synthesized a polarity-viscosity responsive coumarin fluorescent probe, Cou-CN, which achieved sensitive detection of polarity and viscosity in dilute solution environments by constructing this simple probe with ICT and TICT properties and verifying it using Gaussian computational simulation. Cou-CN exhibited good lipid droplet illumination effects in HepG2 cells with a correlation coefficient of 0.92 compared to the commercial lipid droplet dye BODIPY. Additionally, co-staining the probe with the lipophilic commercial dye Nile Red in tobacco root stem seedling cells resulted in a high correlation coefficient of 0.9.