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Clerodendrum viscosum is a traditionally used medicinal plant. The present study aimed to analyze a detailed cytotoxic effect of the nonpolar petroleum ether fraction (AQPEF) of leaf aqueous extract of C. viscosum Vent. (LAECV) in Allium cepa root tip cells. The LAECV was fractionated with petroleum ether and tested for A. cepa toxicity at early hours (2 and 4 h treatment) at concentrations 0, 50, 100, 150 and 200 {micro}g mL-1. The highest aberrant cell percentage (10.45{+/-}0.46%) was scored from 150 {micro}g mL-1 followed by100 {micro}g mL-1 (8.75{+/-}0.26%) concentration at 4 h treated samples. The AQPEF treatment induced a significant (p

Saccharin has been a controversial dietary component because of its potential to aggravate a number of human health disorders. The genotoxic properties of saccharin affect the normal karyokinesis process and results in chromosomal aberrations. In this backdrop, the current study has been formulated to evaluate the genotoxic potential of aqueous saccharin solution using Allium cepa L. assay. Three different concentrations of saccharin solution (0.25%, 0.5% and 1%) and a negative control were used for the root growth inhibition assay. The root length of Allium cepa significantly reduced under saccharin treatments and the effective concentration (EC50) value of the aqueous saccharin solution was determined as 0.587%. The genotoxic effects were determined for the root tip meristematic cells through mitotic index (MI) and mitotic depression (MD) at 3, 6 and 12 h of study. The MI registered highest value without saccharin at low exposure period (17.0 ± 1.5%) while a significant reduction with saccharin application culminated in the lowest MI for 1% saccharin solution at 12 h (3.4 ± 0.4%). MD was found to have a concomitant increase regarding the exposure of the chemical. Higher dose of saccharin for longer exposure time had a gradual decrease in the prophase and simultaneous increase in metaphase and anaphase. Further microscopic observations revealed eight different types of chromosomal aberrations in the A. cepa root tip cells with Anaphase Bridge assuming the highest score. Thus the current study clearly establishes the genotoxic consequences of aqueous solution of saccharin warranting its moderate and regulated dietary intake.

Studying the ability of potassium solubilizing bacteria (KSB) inoculants to partially replace the convential potassium mineral fertilizer (KMF) in carrot fertilizing program, in addition to, clarifying their potential cytotoxicity on mitotic chromosomes division of carrot were conducted in the present investigation. According to field and laboratory experiment results, using the potassium solubilizing bacteria (KSB) as biofertilizer positively affected yield and quality of carrot especially, KSB3 inoculate. On the same direction, KSB and KMF combinations were more efficient than those of KSB and KMF alone. Regarding to the cytotoxic studies, data reveled that carrot root tips treated with KSB and their combinations improved cell division and exhibited low cytotoxicity on mitotic division than those treated with KMF alone. So, it could be concluded that potassium solubilizing bacteria (KSB) inoculants could be used alone or mixed with low doses of KMF as alternative of potassium mineral fertilizer (KMF) in carrot fertilizing programs. In addition, it had less cytotoxicity and ecologically safer than KMF.

Exploration of novel genetic resources against root-knot nematode (RKN) is necessary to strengthen the resistance breeding program in cultivated rice, and investigations on the role of genotype-specific root anatomy in conferring a structural barrier against nematode invasion are largely underexplored. Here, we reported a highly-resistant rice germplasm Phule Radha that conferred remarkably lower RKN parasitic fitness in terms of reduced penetration and delayed development and reproduction when compared with susceptible cultivar PB1121. Using histological and biochemical analyses, we demonstrated that an enhanced suberin deposition in the exodermal root tip tissue of Phule Radha compared to PB1121 can effectively form a penetrative barrier against RKN infection, and this preformed barrier in the control tissue did not necessarily alter to a greater extent when challenged with RKN stress. Using qRT-PCR analysis, we showed that a number of suberin biosynthesis genes were greatly expressed in the exodermis of Phule Radha compared to PB1121. In sum, the present study established the role of rice exodermal barrier system in defense against an important soil-borne pathogen.

In completed research, ferrous gluconate -a food additive- used to preserve black color to prevent discoloration during storage in ripe black olives, and Allium cepa L. species. A. cepa L. roots were treated with different doses of ferrous gluconate. The effective concentration EC50 (0.068 g/l) was determined. A. cepa root tips were treated with EC50/2 (0.034 g/l), EC50 (0.068 g/l), 2XEC50 (0.136 g/l) dose for 24, 48, 72 hours, and afterward, the root tips were prepared for observation under the light microscope according to the method of preparing mitotic preparation. Chromosomal abnormality index (CAI) and genotoxic effect of ferrous gluconate in A. cepa root tip cells were determined. Repeated measurement ANOVA and TUKEY multiple comparison tests were used to investigate the effect of time and dose together on genotoxicity. C-mitosis, polyploidy, polar shifting in anaphase, polar shifting in telophase, equatorial plate shifting, laggard chromosome was observed by microscope. The highest CAI (70.16±4.85) was observed at 72h for 2XEC50 dose. Chromosomal aberration is also observed in control group. While the most common chromosomal aberration is determined as C-mitosis; The least observed chromosomal aberration is determined as polyploidy. Research results revealed that ferrous gluconate has a genotoxic effect on the root tip of A. cepa.

Enaminon türevleriyle aromatik aminlerin diazonyum tuzlarının reaksiyonundan azo boyaları (AD-1, AD-2) sentezlendi. Sentezlenen yeni azo boyanın (AD-2) kimyasal yapısı, elementel analiz ve diğer spektral tekniklerle (FTIR, 1H NMR ve 13C NMR) karakterize edildi. Azo boyaları endüstride sıklıkla kullanılmakta ve özellikle su kaynakları için büyük tehlike oluşturmaktadır. Bu bakımdan azo boyalar tarımsal uygulamalarda birçok ürünü dolaylı olarak tehdit etmektedir. Bu çalışmada, endüstriyel uygulamalarda kullanılabilecek potansiyel azo boyaların (AD-1, AD-2) sitotoksik ve genotoksik etkileri, Allium test sistemi kullanılarak beş farklı konsantrasyonda (6.25, 12.5, 25, 50 ve 100 µM) belirlendi. Sitogenetik analizler sonucunda, her iki azo boyanın da A. cepa hücrelerinin bölünme sayısını önemli ölçüde azalttığı ve bölünen hücrelerde kromozomal anormalliklere neden olduğu belirlendi. Sonuç olarak, bu araştırmada, endüstride potansiyel olarak kullanılabilecek azo boyaların (AD-1, AD-2) canlı yapılarda genotoksik ve sitotoksik etkilere neden olduğu vurgulanmaktadır., Azo dyes (AD-1, AD-2) were synthesized from the reaction diazonium salts of the aromatic amines salt with the enaminone derivative. The chemical structure of the synthesized novel azo dye (AD-2) was characterized by elemental analysis and other spectral techniques (FTIR, 1H NMR and 13C NMR). Azo dyes are used frequently in the industry and pose a great danger especially for water resources. In this respect, azo dyes threaten many products indirectly in agricultural applications. In this study, the cytotoxic and genotoxic effects of potential azo dyes (AD-1, AD-2) that can be used in industrial applications were determined using Allium test system in five different concentrations (6.25, 12.5, 25, 50, and 100 µM). As a result of the cytogenetic analyzes, it was determined that both azo dyes significantly reduced the number of divisions of A. cepa cells and caused chromosomal abnormalities in dividing cells. As a result, in this research, it is emphasized that the azo dyes (AD-1, AD-2), which are potentially used in the industry, cause genotoxic and cytotoxic effects in the living structures.

Made available in DSpace on 2020-12-12T02:44:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Styrax camporum Pohl. (Styracaceae) is a woody species that grows on acidic soils from the Brazilian savanna with high aluminum (Al) saturation (m% > 50%), where it accumulates ~ 1500 mg Al per kg dry leaves. Using nutrient solution, a previous study showed that 1480 μM Al causes toxicity symptoms, which raises the question whether less than 1480 μM Al could cause beneficial effects on this species. Here, we checked possible altered gas exchange rates, damage to organelles in root tips and the association between Al exposure and mitochondria occurrence in cells of root tips, once organic acids from Krebs cycle exuded by the roots of this species when exposed to Al have been recently evidenced. Five-month-old plants were grown in nutrient solution with 0, 740 and 1480 μM Al for 90 days. Plants exposed to 1480 μM Al showed less developed root system, reduced plant height and low gas exchange rates in relation to those exposed to 0 and 740 μM Al, confirming that 1480 μM Al is toxic to S. camporum. However, plants exposed to 0 and 740 μM Al had similar number of leaves, plant height, root biomass, root length, total plant biomass and gas exchange rates, indicating that no beneficial effects from 740 μM Al could be noted on this species. In plants exposed to 0 and 740 μM Al, mitochondria were noted at the root tip, while at 1480 μM Al these organelles were not evident due to the conspicuous vacuolation of root cells. S. camporum shows limited tolerance to Al in nutrient solution. In addition, this species is not dependent on Al to grow and develop because the plants grew well under 0 and 740 μM Al. Departamento de Biodiversidade Instituto de Biociências Programa de Pós-Graduação Em Ciências Biológicas (Biologia Vegetal) Universidade Estadual Paulista UNESP, Av. 24-A, 1515 Departamento de Fitopatologia e Nematologia Escola Superior de Agricultura “Luiz de Queiróz”-Universidade de São Paulo ESALQ-USP, Av. Pádua Dias, 11 Departamento de Biodiversidade Instituto de Biociências Universidade Estadual Paulista UNESP, Av. 24-A, 1515 Departamento de Biodiversidade Instituto de Biociências Programa de Pós-Graduação Em Ciências Biológicas (Biologia Vegetal) Universidade Estadual Paulista UNESP, Av. 24-A, 1515 Departamento de Biodiversidade Instituto de Biociências Universidade Estadual Paulista UNESP, Av. 24-A, 1515 FAPESP: 2014/14386-0 FAPESP: 2018/25658-2 CNPq: 309149/2017-7

The extensive production and utilisation of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) in consumable items may enhance significant increase in fauna and flora exposure. Studies showing the interactive effect of NPs in biological systems are limited. Herein, we showed the cytogenotoxic effects of TiO2 and ZnO NPs, and their mixture (1:1) using the Allium cepa assay. Mitotic index (MI) and chromosomal aberrations (CAs) were assessed in A. cepa L. bulbs exposed to each NP and their mixture at concentrations of 5, 10, 20, 40 and 80 mg L−1, respectively. The recovery effect of the root tip cells from the cytogenotoxic effects of the nanoparticles was also investigated. TiO2, ZnO NPs and their mixture significantly (p

Hormone signals like auxin play a critical role controlling plant growth and development. Determining the mechanisms that regulate auxin distribution in cells and tissues is a vital step in understanding this hormone's role during plant development. Recent mathematical models have enabled us to understand the essential role that auxin influx and efflux carriers play in auxin transport in the Arabidopsis root tip (Band et al., Plant Cell 26(3):862-875, 2014; Grieneisen et al., Nature 449(7165):1008-1013, 2007; van den Berg et al., Development 143(18):3350-3362, 2016). In this chapter, we describe SimuPlant: The Virtual Root (SimuPlant, University of Nottingham. https://www.simuplant.org/ . Accessed 20 Sept 2019); an open source software suite, built using the OpenAlea (Pradal et al., Funct Plant Biol 35(10):751-760, 2008) framework, that is designed to simulate vertex-based models in real plant tissue geometries. We provide guidance on how to install SimuPlant, run 2D auxin transport models in the Arabidopsis root tip, manipulate parameters, and visualize model outputs.SimuPlant features a graphical user interface (GUI) designed to allow users with no programming experience to simulate auxin dynamics within the Arabidopsis root tip. Within the user interface, users of SimuPlant can select from a range of model assumptions and can choose to manipulate model and simulation parameter values. Users can then investigate how their choices affect the predicted distribution of auxin in the Arabidopsis root tip. The results of the model simulations are shown visually within the root geometry and can be exported and saved as PNG image files.

The phloem transport network is a major evolutionary innovation that enabled plants to dominate terrestrial ecosystems. In the growth apices, the meristems, apical stem cells continuously produce early ‘protophloem’. This is easily observed in Arabidopsis root meristems, in which the differentiation of individual protophloem sieve element precursors into interconnected conducting sieve tubes is laid out in a spatio-temporal gradient. The mature protophloem eventually collapses as the neighboring metaphloem takes over its function further distal from the stem cell niche. Compared with protophloem, metaphloem ontogenesis is poorly characterized, primarily because its visualization is challenging. Here, we describe the improved TetSee protocol to investigate metaphloem development in Arabidopsis root tips in combination with a set of molecular markers. We found that mature metaphloem sieve elements are only observed in the late post-meristematic root, although their specification is initiated as soon as protophloem sieve elements enucleate. Moreover, unlike protophloem sieve elements, metaphloem sieve elements only differentiate once they have fully elongated. Finally, our results suggest that metaphloem differentiation is not directly controlled by protophloem-derived cues but rather follows a distinct, robust developmental trajectory.

Callose is cell wall constitutive component of some plant tissues and it is synthesized and deposited in response to stresses (abiotic and biotic). Considering physiological seed quality as an attribute that determines the rapid and uniform emergence of seedlings under a wide range of environmental conditions, this study verified the callose accumulation in seedling roots of soybean cultivars showing contrasting seed vigor under water deficit. Six soybean cultivars were used and the physiological seed quality was determined by germination and vigor tests. Water deficit simulation was performed by germination tests with polyethylene glycol solution at − 0.4 MPa, and the control (0.0 MPa; deionized water). 24 h after radicle protrusion, three samples of 13 root tips were prepared for callose determination. The cultivar ‘BMX Potencia RR’ presented lower germination (87%) when compared to the other cultivars. Vigor results allowed the separation of cultivars into two vigor categories, high and low. The callose concentration deposited on soybean root tissues ranged from 0.0511 to 0.1244 μg per root tip. This allowed the observation of the contrast in callose accumulation between the cultivars during the water deficit, and this is responsive to the greater susceptibility of low vigor cultivars to stress in order to isolate plant tissue through the deposition of a physical barrier. Callose accumulation can be used as indicative of susceptibility to water stress in soybean cultivars.

SummaryClerodendrum viscosum is a traditionally used medicinal plant. The present study aimed to analyze a detailed cytotoxic effect of the nonpolar petroleum ether fraction (AQPEF) of leaf aqueous extract of C. viscosum Vent. (LAECV) in Allium cepa root tip cells. The LAECV was fractionated with petroleum ether and tested for A. cepa toxicity at early hours (2 and 4 h treatment) at concentrations 0, 50, 100, 150 and 200 µg mL-1. The highest aberrant cell percentage (10.45±0.46%) was scored from 150 µg mL-1 followed by100 µg mL-1 (8.75±0.26%) concentration at 4 h treated samples. The AQPEF treatment induced a significant (p-1. The highest polyploid frequency (20.14±0.68 %) induced with 100 µg mL-1 of AQPEF at 16 h recovery. 150 µg mL-1 is the most effective concentration of AQPEF to decipher its activity similar to colchicine (150 µg mL-1). In summary, the present study indicates petroleum ether is suitable for extraction of the active phytochemicals of LAECV having cytotoxic effects on A. cepa root tip cells. The AQPEF has colchicine like micronuclei, polyploidy, and mitotic abnormality inducing potentials in A. cepa root apical meristem cells.

The phloem transport network is a major evolutionary innovation that enabled plants to dominate terrestrial ecosystems. In the growth apices, the meristems, apical stem cells continuously produce early, so-called protophloem. This is easily observed in Arabidopsis root meristems, where the differentiation of individual protophloem sieve element precursors into interconnected, conducting sieve tubes is laid out in a spatio-temporal gradient. The mature protophloem eventually collapses as the neighboring metaphloem takes over its function further distal from the stem cell niche. Compared to protophloem, metaphloem ontogenesis is poorly characterized, primarily because its visualization is challenging. Here we describe an improved protocol to investigate metaphloem development in Arabidopsis root tips in combination with a set of new molecular markers. We found that mature metaphloem sieve elements are only observed in the late post-meristematic root although their specification is initiated as soon as protophloem sieve elements enucleate. Moreover, unlike protophloem sieve elements, metaphloem sieve elements only differentiate once they have fully elongated. Finally, our results suggest that metaphloem differentiation is not directly controlled by protophloem-derived cues but rather follows a distinct, robust developmental trajectory.Summary statementMetaphloem sieve element differentiation in Arabidopsis roots follows a robust developmental trajectory.

The plant root is a dynamic system, which is able to respond promptly to external environmental stimuli by constantly adjusting its growth and development. A key component regulating this growth and development is the finely tuned cross-talk between the auxin and cytokinin phytohormones. The gradient distribution of auxin is not only important for the growth and development of roots, but also for root growth in various response. Recent studies have shed light on the molecular mechanisms of cytokinin-mediated regulation of local auxin biosynthesis/metabolism and redistribution in establishing active auxin gradients, resulting in cell division and differentiation in primary root tips. In this review, we focus our attention on the molecular mechanisms underlying the cytokinin-controlled auxin gradient in root tips.

Auxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies revealed that, beyond transcriptional reprogramming, alternative auxin-controlled mechanisms regulate root growth. Here, we explored the impact of different auxin concentrations on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results together with previously published studies suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31phosphorylation site for growth regulation in theArabidopsisroot tip.ONE SENTENCE SUMMARYAn auxin-triggered Arabidopsis root tip (phospho)proteome reveals novel root growth regulators

Background and Objective. Tibetan medicine is one of the earliest-known traditional medicines. This study aimed to evaluate the antioxidant, cytotoxic, and antibacterial potential of ethanolic extracts of nine common Tibetan formulations. Materials and Methods. An open-ended and semistructured questionnaire was used for an ethnomedicinal survey of the Tibetan formulations practiced in four Tibetan refugee settlements in Gandaki Province, Nepal. Based on the ethnomedicinal survey data, commonly used nine formulations were selected (Aru-18, Basam, Dadue, Dashel, Mutik-25, Raab Ga Yangzin Tea, Serdok-11, Sugmel-10, and Yungwa-4) to test biological activities. Antioxidant activity was evaluated using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging method. The cytotoxicity was examined by using the Allium cepa L. root tip meristem model. Similarly, the antibacterial effect was assessed by using well diffusion and broth dilution methods. Results. An ethnomedicinal survey showed a total of 52 Tibetan formulations were generally used by respondents for common diseases such as stomach disorders, diabetes, and migraine. From the antioxidant activity test, Sugmel-10 showed the highest DPPH free-radical-scavenging activity (IC50 1.8 μg/ml) and Yungwa-4 showed the lowest activity (IC50 5.2 μg/ml). Also, from the cytotoxic activity, the A. cepa root meristem model exhibited significant dose- and time-dependent growth suppression in Basam, Dadue, Mutik-25, and Serdok-11 as compared with cyclophosphamide standard drug. Similarly, Basam showed a good antibacterial effect having MIC 20 mg/ml and MBC 100 mg/ml against Enterococci faecalis. Conclusion. Research showed that Tibetan people preferred Tibetan formulations for the treatment and mitigation of several diseases. The result of antioxidant, cytotoxic, and antibacterial activities experimentally justified the ethnomedicinal value of nine common formulations (Aru-18, Basam, Dadue, Dashel, Mutik-25, Raab Ga Yangzin Tea, Serdok-11, Sugmel-10, and Yungwa-4). To the best of our knowledge, this study was performed for the first time in Nepal. Results from this preliminary study open the door to the scientific world to perform extensive pharmacological studies for designing and developing new therapeutic agents.

The hormonal signals that induce vascular differentiation are the controlling signals that synchronize plant development, organ growth regulation, and feedback cross talks between the shoot and the root. These signals regulate organ development by promoting or inhibiting plant organ growth and therefore should be clarified in order to understand the regulation of vascular differentiation. There is a continuous positive hormonal feedback communication between the shoot apices and the root tips that synchronizes plant development; each plant pole sends its growth-promoting hormonal signal to the opposite side of the plant, informing the other plant pole about its activity and quantity. The major shoot signal produced in the apical bud and young leaves is auxin, while the basic root tip signals produced in the root cap are cytokinins. Auxin promotes the initiation and development of the roots, while cytokinins from the root tips promote the development and growth of the shoot organs. Conversely, as will be clarified in this chapter, due to organ competition, identical organs may cause inhibition, when one of them becomes dominant and retards the others, a phenomenon that was termed apical dominance.

Aluminum (Al) can increase tolerance against abiotic stress, like some other beneficial elements, and provides resistance against biotic stresses. In plants, the Al tolerance mechanism is due to Al active organic acids (OA) secreted from the root tips. Depending on the plant, generally, OAs participating in the detoxification process of Al are malate, citrate, and oxalate in wheat and Arabidopsis malate, in maize citrate, and in buckwheat and tomato oxalate. The Al-activated malate transporter (ALMT) is an omnipresent family, with sequenced genomes all over the plant kingdom. The family name originated after the first identified member involved in stimulating wheat tolerance against Al. In Arabidopsis, AtALMT1 (malate channel) is significant for Al resistance expressed at the plasma membrane (PM) (epidermal cells) of the root tip. In maize, ZmALMT1 is critical for Al resistance. In Arabidopsis, NIP1;2 is a PM-localized transporter mediating Al uptake, translocation, and tolerance.

Auxin is a key signal regulating plant growth and development. It is well established that auxin dynamics depend on the spatial distribution of efflux and influx carriers on the cell membranes. In this study, we employ a systems approach to characterise an alternative symplastic pathway for auxin mobilisation via plasmodesmata, which function as intercellular pores linking the cytoplasm of adjacent cells. To investigate the role of plasmodesmata in auxin patterning, we developed a multicellular model of the Arabidopsis root tip. We tested the model predictions using the DII-VENUS auxin response reporter, comparing the predicted and observed DII-VENUS distributions using genetic and chemical perturbations designed to affect both carrier-mediated and plasmodesmatal auxin fluxes. The model revealed that carrier-mediated transport alone cannot explain the experimentally determined auxin distribution in the root tip. In contrast, a composite model that incorporates both carrier-mediated and plasmodesmatal auxin fluxes re-capitulates the root-tip auxin distribution. We found that auxin fluxes through plasmodesmata enable auxin reflux and increase total root-tip auxin. We conclude that auxin fluxes through plasmodesmata modify the auxin distribution created by efflux and influx carriers., Highlighted Article: A multicellular model of auxin transport in the Arabidopsis root tip reveals the importance of intercellular plasmodesmata in maintaining auxin pattern and fluxes.

Genetic variation in the tissue strength of sugar beet (Beta vulgaris L.) roots has been found in recent studies. There are indications that tissue strength influences damage susceptibility and storability. The objective of this study was to analyse the impact of storage on tissue strength, to determine causes for differences in tissue strength and to find possible relations between tissue strength, damage susceptibility and storability of sugar beet genotypes. For this purpose, trials with six sugar beet genotypes were conducted in seven environments across Germany in 2018 and 2019, followed by a screening trial with 12 commercial genotypes at one location in 2020. Tissue strength changed during storage depending on the growing environment, but independently of the genotype; puncture resistance increased by 0.35 MPa. The genotypic tissue strength was mainly determined by the cell wall content (r² up to 0.97), less by the cell wall composition. For sugar beet genotypes, the relationship between tissue strength and storability could be explained by the fact that root tip breakage and subsequent storage losses tended to decrease with higher tissue strength, as shown by principal component analysis (PCA). Introducing tissue strength as a variety trait in breeding and official variety trials could thus contribute to reduced harvest and storage losses in the future.

Differences in the storability of sugar beet genotypes have been reported to be related to the marc content of beets. Hence, this study aimed at identifying 1) general patterns to characterize varieties and growing sites for low storage losses, 2) the causal relationship between marc content of varieties and their damage susceptibility, infestation with mould and rots and sugar losses after storage, and 3) the environmental stability of the marc content of varieties. For the storage experiments, 10 varieties were grown at 8 sites in Germany, the Netherlands, Belgium and Sweden in 2015, 2016. After harvest, roots were stored for 8 weeks under controlled conditions. To evaluate the environmental stability, the same 10 varieties were grown at 12 sites in D, NL, B, S and Moldova in 2015 and 11 sites in D, NL, B, S in 2016. The results demonstrate a marked effect of the site on the extent of root tip breakage and surface damages, on infestation with mould and rots and on storage losses (invert sugar content, sugar losses). A general pattern could be identified: in most cases, a higher marc content of varieties coincided with less damages and less infestation with mould and rots, resulting in lower sugar losses. With the exception of variety 1, the marc content provided an indication of the storability of the varieties. The marc content turned out to be a very stable variety trait. These results indicate possibilities for breeding and selection for higher marc content and presumed better storability.

The present study evaluates the cytogenetic effects of both silver and gold nanoparticles on the root cells of Allium cepa. In this study, the root cells of Allium cepa were treated with both gold and silver nanoparticles of different concentrations (1 mg/L, 5 mg/L and 10 mg/L) along with control for 72 h. Experimental results revealed that after 72 h of exposure, a significant decrease in mitotic index (MI) from 68% (control) to 52.4% (1 mg/L), 47.3% (5 mg/L) and 41.4% (10 mg/L) for gold nanoparticles and 57.1% (1 mg/L), 53% (5 mg/l), 55.8% (10 mg/L) for silver nanoparticles. Through minute observation of the photograph, it was recorded that some specific chromosomal abnormalities such as stickiness of chromosome, chromosome breaks, nuclear notch, and clumped chromosome at different exposure conditions. Therefore, present results clearly suggest that Allium cepa root tip assay could be a viable path through which negative impact of both gold and silver nanoparticles can be demonstrated over a wide range of concentrations. Keywords: Allium cepa, Gold nanoparticles, Silver nanoparticles, Mitotic index, Chromosomal aberrations

Phosphorous (P) deficiency induces root cortical aerenchyma (RCA) formation in Chinese fir seedlings with marked genotypic variation, and the adaptive role of RCA is mainly related to root P reduction. Root cortical aerenchyma (RCA) formation in response to phosphorus (P) deficiency and its adaptive role are largely unexplored in trees. We hypothesized that RCA formation in response to P deficiency varies with its severity and genotype, and that P-stressed seedlings maintain similar seedling growth to non-stressed seedlings by reducing the P requirements of roots and metabolic cost of soil exploration. Seedlings of two half-sib families (nos. 25 and 36) of Cunninghamia lanceolata (Chinese fir) were grown in pots with three levels of P supply for 3 months. Significant differences in RCA formation in 40–45 mm root segments from the root tip were observed between families and P supply levels. Severe P deficiency induced more RCA formation in family no. 36 than in family no. 25, whereas moderate P deficiency induced RCA formation in family no. 36 only. Family no. 36 had significantly higher height increment, needle biomass, and P concentration in stems and needles, but lower root biomass and root P concentration, than family 25. A significantly negative relationship was found between RCA and root P concentration, increments in average root diameter, and root surface area, whereas significantly positive correlations were observed between some root morphological traits and biomass and P concentration in the organs of P-stressed seedlings of family 36. In conclusion, severe P deficiency induces formation of RCA in Chinese fir seedlings with marked genotypic variation, and the adaptive role of RCA formation during P deficiency is mainly related to the reduction of root P concentration.

The harmful potential of the Colorado potato beetle (Leptinotarsa decemlineata (Say)), and its resistance to many insecticides in current use have drawn the attention of specialists across the worl...

Due to continued industrial discharge, pollution of the aquatic system has emerged as a worldwide concern. This study was conducted to determine the possible genotoxic effect of industrial effluents (treated and untreated) by employing the Allium cepa chromosome aberrations test system. The result illustrated that the untreated effluent was more toxic compared to treated effluent, as it reduced the number of dividing cells in the root tip. All the samples of untreated effluent showed high genotoxic effect. On incrementing the dosage from 25% to 100% the gradual increasing effect was noted on A. cepa. The study states that effluent even after treatment remains genotoxic as it has the ability to initiate the chromosomal aberrations of various types.

The present investigation was undertaken to evaluate the genotoxic effect of zinc nanoparticles (ZnNPs) synthesized by leaf extract of Albizia saman on mitotic chromosomes of root tip meristematic ...

Soybean is the important crop with abundant protein, vegetable oil, and several phytochemicals. With such predominant values, soybean is cultivated with a long history. However, flooding and drought stresses exert deleterious effects on soybean growth. The present review summarizes the morphological changes and affected events in soybean exposed to such extreme-water conditions. Sensitive organ in stressed soybean at different-developmental stages is presented based on protein profiles. Protein quality control and calcium homeostasis in the endoplasmic reticulum are discussed in soybean under both stresses. In addition, the way of calcium homeostasis in mediating protein folding and energy metabolism is addressed. Finally, stress response to flooding and drought is systematically demonstrated. This review concludes the recent findings of plant response to flooding and drought stresses in soybean employed proteomic approaches. Biological significance Soybean is considered as traditional-health food because of nutritional elements and pharmacological values. Flooding and drought exert deleterious effects to soybean growth. Proteomic approaches have been employed to elucidate stress response in soybean exposed to flooding and drought stresses. In this review, stress response is presented on organ-specific manner in the early-stage plant and soybean seedling exposed to combined stresses. The endoplasmic reticulum (ER) stress is induced by both stresses; and stress-response in the ER is addressed in the root tip of early-stage soybean. Moreover, calcium-response processes in stressed plant are described in the ER and in the cytosol. Additionally, stress-dependent response was discussed in flooded and drought-stressed plant. This review depicts stress response in the sensitive organ of stressed soybean and forms the basis to develop molecular markers related to plant defense under flooding and drought stresses.

Gibberellin (GA) has been shown to exert numerous beneficial physiological functions in the resistance of plant to various abiotic stresses, however, the mechanism of GA for the mitigation of Cd stress in vegetables has not been well established. This study was carried out to investigate the effect of GA on the growth and Cd uptake in lettuce plants. Result showed that 10 µmol/L GA treatment restored part of the root morphology and vigor of lettuce under Cd stress by increasing the total root length, surface area and total root tip number, which directly showed an increased biomass of lettuce. On the other hand, GA reduced Cd uptake by roots and Cd root-to-shoot translocation by down-regulated expression of IRT1, Nramp1, HMA2 and HMA4, which finally alleviated the toxic effects of Cd on lettuce leaves, as confirmed by Non-invasive micro-test Technique (NMT) results. Overall, these findings provide new insights into the mechanism of cadmium toxicity mitigation in vegetables by GA and provide a theoretical basis for the development of physiological blockers with gibberellin components.

Regulation of flowering is one of the key issues in crop yield. The Flowering Locus T ( FT ) gene is a well-known florigen, which integrates various signals from multiple flowering-regulation pathways to initiate flowering. We previously reported that there are at least six FT genes ( GmFTL1 – 6 ) in soybean displaying flowering activity. However, the individual functions of genes GmFTL1 – 6 remain to be identified. In this study, we cloned the GmFTL2 promoter ( GmFTL pro ) from soybean ( Glycine max ) cultivar Tianlong 1 and analyzed its motifs bioinformatically and its expression patterns using both a transgenic approach and quantitative RT-PCR (qRT-PCR). In GmFTL pro :: GUS transgenic lines, GUS signals were enriched in cotyledons, hypocotyledons, pollen, embryos, and root tips in a photoperiod-independent manner. qRT-PCR confirmed the GUS reporter results. Our results suggest that GmFTL2 expression is regulated by developmental and tissue-specific clues and plays roles in seedling establishment and the development of microgametophytes, embryos, and roots.

Premise of research. The Australian members of the genus Craspedia (Asteraceae: Gnaphalieae) are known to contain polyploids, but only a very limited number of chromosome counts are available, and a systematic overview of ploidy levels and genome sizes is lacking. In the present study, we aimed to document chromosome number variation across the genus in Australia, test whether polyploids occur more often in alpine than in lowland environments, and test whether there is a proportional increase in genome size with polyploidy that would enable the use of flow cytometry as a proxy for chromosome counts in future studies.Methodology. We used flow cytometry to measure genome sizes (2C values) of 59 individual plants and obtained 45 chromosome counts from root tip squashes.Pivotal results. We found polyploidy to be common and documented intraspecific ploidy variation in several species, indicating multiple independent origins of polyploidy within the genus. Polyploidy was not more prevalent in high-elevation spe...

Duckweed is considered to be one of the most attractive higher plants to provide the life support requirements of the crew in long-duration space missions. Two species of duckweed, Lemna aequinoctialis and Wolffia globosa, were comparatively studied with focus on the effects of simulated microgravity conditions. A significant enhancement of plant relative growth rate (RGR) was observed under simulated microgravity conditions. The mean RGR of L. aequinoctialis was 32% increased, and W. globosa was 12% increased compared to control. Light and electron microscope analyses showed that the mesophyll cells of duckweed fronds were loosely arranged and many intercellular air spaces enclosed by mesophyll cells were observed in reaction to simulated microgravity, and few starch grains were detected in root tip cells in L. aequinoctialis under simulated microgravity conditions. For L. aequinoctialis, the starch content was significantly increased under simulated microgravity conditions. Thus, the starch content of W. globosa under simulated microgravity conditions was kept stable during all growth periods. This pattern might be associated with the different expression change of the rate-limiting gene APL in regulating starch levels. Taking into consideration of the duckweed growth, ultra-structure and starch content changes, we considered that simulated microgravity conditions do not have a significant adversely affect on the duckweed growth.

Rehmannia glutinosa L. (R. glutinosa) is one of the most common traditional Chinese medicines, whose productivity and quality, however, are seriously impacted by replanting disease, also known as consecutive monoculture obstacle. Little is known about R. glutinosa’s critical responsive stage to consecutive monoculture. There were two parts to this study: first, we analyzed different gene expression profiles in root of R. glutinosa between first-year planting (FP) and second-year replanting (SP) in five development stages (stage I to V) using Illumina sequencing to interpret the stage that most dramatically responding to consecutive monoculture; second, applying tissue culture technique, the harm of consecutive monoculture in a sterile condition was simulated and the medium was added with the soil extracts from FP and SP soil. The results showed that a significant difference in gene expression appeared at stage I under consecutive monoculture. Using a calcium indicator, the fluo-3 fluorescence to detect calcium distribution in the root tip of seedlings cultured in medium, the results revealed that after being cultured for 10 days, the SP fluorescence intensity of the seedlings was significantly higher than that of FP while crown position was particularly prominent. The evidence from gene expression profiling and tissue culture reached agreement that early stage of R. glutinosa growth was the critical stage to perceive consecutive monoculture stress. The results are of great significance to study the molecular mechanism of consecutive monoculture, which is expected to await a quick and accurate evaluation of land feasibility to plant R. glutinosa.

Trees growing in wetlands develop adventitious roots from the trunk during the rainy season and adapt to the flooded environment by forming primary (schizogenous or lysigenous) and secondary aerenchyma in the roots. Therefore, it is necessary to clarify the formation process of each type of aerenchyma in these adventitious roots. In this study, saplings of Syzygium kunstleri (King) Bahadur and R.C.Gaur were grown under four different treatments, and a total of 12 adventitious roots generated from trunks were used to clarify the distribution of each aerenchyma type in the roots using light or epi-florescence microscopy. Schizogenous aerenchyma was observed in the root tips where the root color was white or light brown, whereas lysigenous aerenchyma was found at some distance from the root tip where the root color gradually changed from light to dark brown. The secondary aerenchyma and periderm were observed in dark brown parts near the root base. None or only one layer of phellem cells was detected in the white roots near the root tip, but dark brown roots near the root base had at least three layers of phellem cells. Considering these results, oxygen transportation may occur between primary and secondary aerenchyma at the point where two or more layers of phellem cells are formed.

Gibberellic acid (GA) is a natural plant growth regulator (PGR) which stimulates germination, vegetative growth, flowering, and fruit formation. However, when high concentrations of GA are used, it inhibits plant growth and development and causes abnormalities in the plant tissue. In our study, we determined the effects of different concentrations of GA on Allium cepa L. var. cepa roots. Increasing concentrations of GA (50 - 5 000 mg dm-3) were used in A. cepa root growth inhibition tests. Further, random amplified polymorphic DNA technique was used for determination of possible genotoxic effects of 600 - 1200 mg dm-3 GA on A. cepa root tips. Our findings show cytotoxic and genotoxic effects of these concentrations of GA and indicate that the difference among control and treatment groups were statistically significant.

Highlights • Cell ablation mimics wounding on a single cell level. • Calcium, ROS, and hormone dynamics were described. • Local, regional, and systemic responses can be distinguished., Plants as sessile organisms are constantly under attack by herbivores, rough environmental situations, or mechanical pressure. These challenges often lead to the induction of wounds or destruction of already specified and developed tissues. Additionally, wounding makes plants vulnerable to invasion by pathogens, which is why wound signalling often triggers specific defence responses. To stay competitive or, eventually, survive under these circumstances, plants need to regenerate efficiently, which in rigid, tissue migration-incompatible plant tissues requires post-embryonic patterning and organogenesis. Now, several studies used laser-assisted single cell ablation in the Arabidopsis root tip as a minimal wounding proxy. Here, we discuss their findings and put them into context of a broader spectrum of wound signalling, pathogen responses and tissue as well as organ regeneration.

In the present study, a bottom-up approach to phytosynthesis of silver oxide nanoparticles (Ag2O-NPs) using hydroalcoholic extracts of Helleborus odorus Waldst. & Kit. Ex Willd. as a reducing agent is reported. Evaluation of cytogenotoxic effects of the extracts, prior to and after Ag2O-NPs green synthesis, on Allium cepa L. root tip cells was evaluated. The synthesis of Ag2O-NPs (suggested by UV–Vis adsorption spectrum) was confirmed using X-ray diffraction and transmission electron microscopy. The strong mitoinhibitory and chromatoclastic effects of crude extracts of H. odorus Waldst. & Kit. Ex Willd. on meristematic root-tip cells of onion were intensified by the phytofabricated Ag2O-NPs, thus suggesting their potential use as antitumor agents.

Fine root dynamics and root architecture were studied in the organic and mineral soil layers of a Cryptomeria japonica plantation. Fine root biomass (

Sweet potato is now classified among the high-priority crops targeted at reducing food insecurity and malnutrition in many countries. Despite this growing interest, high postharvest losses caused by poor handling, physiological weight loss, sprouting, weevil (Cylas spp.) damage and microbial decay remain a challenge. Decay losses due to tip rot and other pathogenic fungi are a challenge in Ghana. Incidence of tip rot, which is characterized by a dry decay at either or both ends of roots, is severe due to late harvesting of roots which are intended for storage. This study evaluated a series of postharvest techniques which can be integrated to extend shelf-life in small scale storage. These include harvest maturity, root tip coppicing, hot water treatment, honey waxing and sanitizing in postharvest chemicals. Tip coppicing significantly (P

Nonstructural carbohydrates (NSCs) are a key factor in the physiological regulation of plants and can reflect buffering capacity of plants under diverse environmental conditions. The effects of diverse environmental conditions on plant NSCs and tissue or organ scales have been thoroughly studied, but their effects on fine root (root diameter &lt, 2 mm) NSC concentrations are still not completely understood. Our aims were to explore the synergistic fluctuations in root traits and NSC concentrations under diverse environmental conditions. This study was conducted on two-year-old temperate seedling tree species (Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., and Phellodendron amurense Rupr.) with different drought intensities and soil substrates. The specific root length (SRL) and specific root surface area (SRA) were significantly affected by drought intensities and soil substrates, while the root tissue density (RTD) and average diameter (AD) were not significantly affected by water intensities and soil substrates in all three species. The root C, N, and P concentration did not change according to drought stress but were significantly affected by the soil substrates in all three species. Similarly, the soluble sugar (SS) and starch (ST) concentrations were significantly affected by both the drought stress and the soil substrates in all three species. The AD explained 6.8% of the total variations in soluble sugar, while the SRL explains 32.1% of the total variation in starch. The root tip C, N, and P concentrations were not significantly correlated with NSCs under different treatments. The total variations in root tip morphology, chemistry, and NSC concentrations are greater among species than compared to different drought intensities and soil substrates. However, the root NSC concentrations were closely related to root morphological traits (SRL and AD) rather than chemical traits. On the basis of different soil resources, the species with thinner diameters have higher SS concentrations, while those of a thicker diameter have higher ST concentrations.

Raspberry subcultured tissue seedlings were used as test materials for the effect of different concentrations of graphene on the growth of raspberry seedlings and the development of adventitious roots. The graphene was characterized by a laser particle size analyzer, STEM, TEM, XPS and Raman spectroscopy. A root analysis system and SEM were used to systematically characterize the seedling height, root length, root specific surface area, number of branches, number of root tips and root micromorphology, thus determining the optimum concentration of graphene for the growth of raspberry tissue culture seedlings. The results showed that with increasing graphene concentration, the seedling height, root length, root tip number and root specific surface area of the seedlings all showed a trend of first increasing and then decreasing. The optimum concentration of graphene was 2 mg·L-1, the seedling height of tissue culture seedlings was 1.46 times that of the control group, and the root length, specific surface area, number of root tips and their bifurcation number were about twice that of the control group.

Regulation of plant root angle is critical for obtaining nutrients and water and is an important trait for plant breeding. A plant’s final, long-term root angle is the net result of a complex series of decisions made by a root tip in response to changes in nutrient availability, impediments, the gravity vector and other stimuli. When a root tip is displaced from the gravity vector, the short-term process of gravitropism results in rapid reorientation of the root toward the vertical. Here, we explore both short- and long-term regulation of root growth angle, using natural variation in tomato to identify shared and separate genetic features of the two responses. Mapping of expression quantitative trait loci mapping and leveraging natural variation between and within species including Arabidopsis suggest a role for PURPLE ACID PHOSPHATASE 27 and CELL DIVISION CYCLE 73 in determining root angle.

To elucidate dynamic developmental processes in plants, live tissues and organs have to be visualized frequently and for long time periods. The development of roots is studied in depth at a cellular resolution not only to comprehend the basic processes fundamental to maintenance and pattern formation but also study stress tolerance adaptation in plants. Despite technological advancements, maintaining continuous access to samples and simultaneously preserving their morphological structures and physiological conditions without causing damage presents hindrances in the measurement, visualization and analyses of growing organs including plant roots. We propose a preliminary system which integrates the optical real-time visualization through light microscopy with a liquid culture which enables us to image at the tissue and cellular level horizontally growing Brachypodium roots every few minutes and up to 24 hours. We describe a simple setup which can be used to track the growth of the root as it grows including the root tip growth and osmotic stress dynamics. We demonstrate the system’s capability to scale down the PEG-mediated osmotic stress analysis and collected data on gene expression under osmotic stress.