Increased Root Length Research Articles

Characterization of ZmPMP3g function in drought tolerance of maize

The genes enconding proteins containing plasma membrane proteolipid 3 (PMP3) domain are responsive to abiotic stresses, but their functions in maize drought tolerance remain largely unknown. In this study, the transgenic maize lines overexpressing maize ZmPMP3g gene were featured by enhanced drought tolerance; increases in total root length, activities of superoxide dismutase and catalase, and leaf water content; and decreases in leaf water potential, levels of O2−·and H2O2, and malondialdehyde content under drought. Under treatments with foliar spraying with abscisic acid (ABA), drought tolerance of both transgenic line Y7-1 overexpressing ZmPMP3g and wild type Ye478 was enhanced, of which Y7-1 showed an increased endogenous ABA and decreased endogenous gibberellin (GA) 1 (significantly) and GA3 (very slightly but not significantly) and Ye478 had a relatively lower ABA and no changes in GA1 and GA3. ZmPMP3g overexpression in Y7-1 affected the expression of multiple key transcription factor genes in ABA-dependent and -independent drought signaling pathways. These results indicate that ZmPMP3g overexpression plays a role in maize drought tolerance by harmonizing ABA-GA1-GA3 homeostasis/balance, improving root growth, enhancing antioxidant capacity, maintaining membrane lipid integrity, and regulating intracellular osmotic pressure. A working model on ABA-GA-ZmPMP3g was proposed and discussed.

Response of various growth regulators and shade intensity to the growth of arabica coffee seedlings of Sigarar Utang variety

Abstract. Damanik RIM, Hanum C, Sembiring LJ. 2023. Response of various growth regulators and shade intensity to the growth of arabica coffee seedlings of Sigarar Utang variety. Nusantara Bioscience 15: 85-89. The productivity of Arabica coffee (Coffea arabica L.) of the Sigarar Utang variety in Indonesia is still relatively low, especially in Simalungun District, North Sumatra Province, Indonesia. Growth regulators and shade are some factors that must be considered in nurseries. This research aims to determine the best growth regulators type and shade intensity for Arabika coffee seedling growth. The experiment was conducted from March to June 2022 in Nagori Ujung Bawang, Simalungun District, and the Central Laboratory of Agriculture Faculty, Universitas Sumatera Utara, Medan, North Sumatra. The study used a Split Plot design of 2 factors and 3 replications. The first factor (main plot) consists of 4 levels, namely 0, 50, 70, and 90% shade intensity. The second factor (sub-plot) consists of the three growth regulator treatments, i.e., auxin, cytokinin, and the combination of auxin and cytokinin. The results showed that the interaction between shade intensity and growth regulators had a significantly different effect on increasing root length. The shade treatment significantly affected plant height, leaf area, and total chlorophyll content of leaves. However, it did not affect the stem diameter. A shade intensity of 90% significantly increased plant height, leaf area, and total chlorophyll content of leaves.

Garlic Ecotypes Utilise Different Morphological, Physiological and Biochemical Mechanisms to Cope with Drought Stress.

Drought negatively affects plants by altering morphological, physiological and metabolic processes and ultimately reducing yields. Garlic (Allium sativum L.), an important member of the Alliaceae family, is also sensitive to drought and maximizing the yield of garlic bulbs is largely dependent on water availability. The objective of this study was to determine the effects of drought stress on morphological and physiological characteristics, as well as on phenolic, sugar, inulin and free amino acid content and antioxidant activity in two Croatian garlic ecotypes, 'Istarski crveni' (IC) and Istarski bijeli (IB). Drought was induced by using polyethylene glycol 8000 (PEG) solution (-0.6 MPa) starting 21 days after clove planting and lasted for 20 days. Drought reduced plant height, number of leaves and plant weight, but increased root length in both ecotypes compared to the control treatment. Among the physiological parameters, significant differences were observed between the two ecotypes studied in the spectral characteristics of the leaves, namely reflection in red, green and blue, VAL, values of the vegetation indices related to the chlorophyll content (CHI, GI), and the anthocyanin content (ARI). Ecotype IC showed higher antioxidant activity in the control treatment due to higher total phenolic content (TPC), but under drought conditions higher DPPH radical scavenging activity was determined in ecotype IB and higher values of FRAP in IC. Sucrose and glucose generally decreased under drought, while inulin increased in IB but decreased in IC. Total free amino acid content increased under drought in both ecotypes. In conclusion, drought tolerance of IB might be associated with increased accumulation of inulin and higher levels of amino acids, especially those shown to contribute to drought resistance. In IC, drought tolerance is associated with an increase in some amino acid compounds and better root growth in depth, probably due to a more efficient translocation of sucrose to the underground part of the plant.

A 1-aminocyclopropane-1-carboxylate deaminase MrACCD from Metarhizium robertsii is associated with plant growth promotion for Metarhizium spp

Besides killing insects, Metarhizium spp. have shown another ecological role as plant associates. Partial genra and groups of these entomopathogenic fungi act as plant growth promoters during root colonization. Here, we report that Metarhizium robertsii produces a 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD encoded by MracdS, MrACCD), which is involved in promoting early vegetative growth in wheat, while Metarhizium acridum lacks a functional ACCD, although a gene encoding for a putative ACCD has been identified in its genome. MracdS expression was up-regulated by a max 10.7-fold with 3 mM ACC and high ACCD enzymatic activities were induced by either ACC (7.5-fold) or wheat root (3.2-fold). In contrast, no ACCD activity was detected in M. acridum in the presence of both inducers. In pot assay, wheat seeds were treated with wild-type M. robertsii (Mr23), wild-type M. acridum (Mac324), MracdS disruption mutant (ΔMracdS) and M. acridum transformant harboring heterologous MracdS (Mac324-MracdS). Relative to the control seeds treated with heat-killed conidia, Mr23, ΔMracdS and Mac324-MracdS increased root length (by 66.2, 31.8 and 40.2%), and plant biomass (by 56.6, 42.1 and 40.9%). Nevertheless, ΔMracdS deficient in ACCD activity heavily impaired its capability of wheat growth promotion by decrease of 20.7% in root length relative to Mr23. In addition, Mr23 and Mac324-MracdS also increased shoot growth (by 42.3, and 42.7%) while ΔMracdS failed. Mac324 showed no effect on plant growth during the test. These data suggest a role for ACCD in the plant growth promotion effect by M. robertsii, which is irrelevant to Metarhizium colonization of roots since rhizosphere competency of both Mr23 and Mac324 are unaffected by the change of ACCD activity.

The effect of pre-sowing electron radiation on the development of barley seedlings and the activity of enzymes and phytohormones

In a laboratory experiment, the effect of pre-sowing low-energy (160 keV) electron radiation at doses of 1, 3, and 5 kGy at a dose rate of 500 Gy/pulse was studied. on sowing qualities, morphometric parameters of barley seedlings of the Vladimir spring variety, their susceptibility to fungal diseases against a natural infectious background, as well as on the activity of enzymes and the concentration of phytohormones in 7-day-old seedlings. The repetition in the experiment was 3-fold, non-irradiated seeds served as control. Irradiation of seeds at a dose of 3 kGy caused a statistically significant increase in comparison with the control of laboratory germination (LV) by 6 % and seed growth force (SPC) by 10 %, and at a dose of 1 kGy, an increase in root length by 24.6 % and had no significant effect on morphometric parameters at a dose of 5 kGy. Seed treatment did not affect the green and dry weight of the seedlings and the percentage of water content in them. Irradiation completely suppressed the development of Penicillium spp. at doses of 1, 3 and 5 kGy, Fusarium spp. - at doses of 3 and 5 kGy and significantly increased the prevalence of Bipolaris sorokiniana seedlings by 2.1 times and its prevalence by 1.8 times at a dose of 5 kGy. Electron irradiation of barley seeds had no effect on the activity of enzymes and phytohormones, except for a significant increase in 7-day-old seedlings of the content of IAA at a dose of 5 kGy by 1.5 times and IBA at a dose of 1 kGy by 2.7 times compared with the control.

Effects of Multi-Walled Carbon Nanotubes and Nano-Silica on Root Development, Leaf Photosynthesis, Active Oxygen and Nitrogen Metabolism in Maize.

Carbon nanotubes (MWCNTs) and nano-silica (nano-SiO2) are widely used in the field of life science because of their special physical and chemical properties. In this study, the effects of different concentrations of MWCNTs (0 mg·L-1, 200 mg·L-1, 400 mg·L-1, 800 mg·L-1 and 1200 mg·L-1) and nano-SiO2 (0 mg·L-1, 150 mg·L-1, 800 mg·L-1, 1500 mg·L-1 and 2500 mg·L-1) on maize seedling growth and relative mechanisms were explored. The main results are as follows: MWCNTs and nano-SiO2 can promote the growth of maize seedlings, and promote plant height, root length, the dry and fresh weight of seedlings, root-shoot ratio and so on. The ability to accumulate dry matter increased, the relative water content of leaves increased, the electrical conductivity of leaves decreased, the stability of cell membranes improved and the water metabolism ability of maize seedlings increased. The treatment of MWCNTs with 800 mg·L-1 and nano-SiO2 with 1500 mg·L-1 had the best effect on seedling growth. MWCNTs and nano-SiO2 can promote the development of root morphology, increase root length, root surface area, average diameter, root volume and total root tip number and improve root activity, so as to improve the absorption capacity of roots to water and nutrition. After MWCNT and nano-SiO2 treatment, compared with the control, the contents of O2·- and H2O2 decreased, and the damage of reactive oxygen free radicals to cells decreased. MWCNTs and nano-SiO2 can promote the clearance of reactive oxygen species and maintain the complete structure of cells, so as to slow down plant aging. The promoting effect of MWCNTs treated with 800 mg·L-1 and nano-SiO2 treated with 1500 mg·L-1 had the best effect. After treatment with MWCNTs and nano-SiO2, the activities of key photosynthesis enzymes PEPC, Rubisco, NADP-ME, NADP-MDH and PPDK of maize seedlings increased, which promoted the opening of stomata, improved the fixation efficiency of CO2, improved the photosynthetic process of maize plants and promoted plant growth. The promoting effect was the best when the concentration of MWCNTs was 800 mg·L-1 and the concentration of nano-SiO2 was 1500 mg·L-1. MWCNTs and nano-SiO2 can increase the activities of the enzymes GS, GOGAT, GAD and GDH related to nitrogen metabolism in maize leaves and roots, and can increase the content of pyruvate, so as to promote the synthesis of carbohydrates and the utilization of nitrogen and promote plant growth.

Predation pressure regulates plant growth promoting (PGP) attributes of bacterial species.

The present study aimed to investigate the effect of bacterivorous soil protists on plant growth promoting (PGP) attributes of bacterial species and their co-inoculative impact on rice seedling growth. The effect of protists on the PGP attributes of bacteria was tested using standard protocols. The results revealed that the plant-beneficial properties of plant growth promoting bacteria (PGPB) were altered in the presence of various protist species. A significant increase in the production of siderophore units (86.66%), ammonia (34.80µmol mL-1), and phosphate solubilization index (PSI) (5.6) was observed when Bacillus cereus (Bc) and Pseudomonas fluorescens (Ps) were co-inoculated with unidentified species belonging to the family Kreyellidae (C5). In the case of Enterobacter cloacae co-inoculated with C5 (Kreyellidae), a higher amount of siderophore (51.33%), ammonia (25.18µmol mL-1), and indole-3-acetic acid (IAA)-like substance (28.59µg mL-1) production were observed. The biofilm-forming ability of B. cereus is enhanced in the presence of Tetrahymena sp. (C2Bc), unidentified Kreyellidae (C5Bc), and Colpoda elliotti (C12Bc), whereas E. cloacae showed higher biofilm formation in the presence of Tetrahymena sp. alone Although IAA production decreased under predation pressure, a significant increase in shoot length (64.24%) and primary root length (98.18%) in co-inoculative treatments (C12Bc and C5Bc) compared to bacteria alone (25% and 61.50% for shoots and roots respectively) was observed. The results of enhanced PGP attributes and rice seedlings growth under predation pressure correlated with the enhanced bacterial activity under predation pressure and protist involvement in plant growth development. Protists may act as regulators of the bacterial activities involved in plant growth promotion and thus enhance plant growth.

Potential to Improve Wyoming Big Sagebrush Establishment with a Root-Enhancement Seed Technology

Restoration of the foundational species, big sagebrush (Artemisia tridentata Nutt.), of the sagebrush steppe biome has not kept pace with the loss of habitat, demanding new tools to improve its restoration. Seed enhancement technology (SET) is one approach that is increasingly being tested in native plant restoration as a means to overcome establishment barriers. Like many semiarid shrubs, sagebrush faces establishment barriers from inadequate moisture, competition from faster-growing grasses, and limited available nutrients. We performed a series of laboratory trials testing whether nutrient amendments could be applied to sagebrush seed using a SET to increase root length and biomass, thereby potentially increasing seedling survival. We initially tested 11 amendments applied directly to bare seeds; of these, a high-phosphorus fertilizer resulted in a 2.7x increase in root biomass and 71-mm increase in root length over the control. We then tested incorporating this fertilizer at multiple concentrations into a pellet SET and a ground dust. Although the fertilizer, particularly at higher concentrations, conferred some enhancement to seedling biomass, the pellet treatments had substantially lower emergence and survival than bare seed and dust treatments. These results indicate the potential for a “root-enhancement” SET to benefit sagebrush and other species like it; they also illustrate some of the challenges of SET development for native species. Sagebrush has small seeds that typically need light to germinate. Further work is needed to develop an appropriate technology that does not negatively impact emergence but still provides enough nutrients for enhanced root growth. Field testing is also needed to determine if increases in root growth translate into greater survival. Given the low success rate of sagebrush seeding in restoration projects, however, we suggest that it is worth considering root-enhancement SET alongside other efforts to improve sagebrush establishment success.

Dental stem cells and tissue regeneration in odontology: a brief systematic review

Introduction: New ideas for tooth and tissue regeneration began to appear with rapid developments in tissue engineering theories and technologies. Numerous types of stem cells have been isolated from dental tissue, such as dental pulp stem cells (DPSC), human pulp stem cells isolated from exfoliated primary teeth (SHED), periodontal ligament stem cells (PDLSC), apical papillary stem (SCAP) and dental follicular cells (DFC). All these cells can regenerate tooth tissue. Objective: It was to present the main considerations of bioengineering techniques and report the results obtained in experiments with dental stem cells, as well as their real trends in application in dentistry. Methods: The systematic review rules of the PRISMA Platform were followed. The search was carried out from October to December 2022 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases, using articles from 2001 to 2022. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed accordingly, according to the Cochrane instrument. Results and Conclusion: A total of 118 articles were found, 27 articles were evaluated and 16 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 29 studies with a high risk of bias and 42 studies that did not meet GRADE. It is concluded that the collection of mesenchymal stem cells from deciduous teeth should be widely disseminated, as it is of great importance and wide applicability, allowing the repair of the most diverse cell types. In addition, it has several advantages, such as a non-invasive technique, respecting the period of dentition change, there are more than 20 collection possibilities, it presents high compatibility with the donor and family members and storage for an indefinite period. The studies showed that implantation of stem cells from deciduous teeth led to the regeneration of three-dimensional pulp tissue equipped with blood vessels and sensory nerves up to 12 months after treatment, as well as increased root length and reduced apical foramen width, not showing adverse events over 24 months of follow-up.

Effect Trichoderma spp on Wheat ( Triticum aestivum)

The objective this study were to determine effect of Trichoderma spp and Humic acid 60% on three Varieties of wheat (Triticum aestivum). The study included two factors, first factor was immersion of seeds in Humic acid 60% solution Humic acid 60% + Trichoderma spp150Mg/l, Humic acid 60% + Trichoderma spp 250Mg/l, symbols T1, T2, T3, T4 respectively. The second factor is three varieties of wheat (Iba99, Adina, Dijlla) and the plant variety is represented by V1, V2, V3 respectively. Treatments were Design (RCBD) with three replicates Statistics were evaluated followed by Duncan multiple range test to compare means at P< (0.05). Data presented the use of Humic acid 60% + Trichoderma spp250 Mg/l led to a significant increase in the studied traits as well as the interaction between variables where treatment V2T4 were highest significant increase in plant height, root length and spike length, which reached 95.07 cm plant height, 14.93 cm length Root, spike length is 11.50 cm, while treatment V1T4 were the highest significant increase in leaf reach, reaching 26.80 cm.

In vitro propagation of Geranium wallichianum: An indigenously threatened medicinal plant in Pakistan

Geranium wallichianum is a well-known medicinal plant and has numerous ethnobotanical usages but its population in Pakistan is severely reducing due to overexploitation and over-harvesting. Moreover, the conventional propagation systems are not enough to sustain the population and meet the ever-increasing demand for this plant. Therefore, an efficient propagation system is necessary to conserve and increase the population of this plant. To control browning, citric acid, ascorbic acid and activated charcoal were added to Murashige and Skoog (MS) medium. The 2,4-dichlorophenoxyacetic acid (2,4-D) and naphthaleneacetic acid (NAA) were used in different concentrations to induce the callus while shoot proliferation and root induction were achieved with media supplemented with 6-benzyl aminopurine (BAP), and indole-3-butyric acid (IBA), respectively. Callus was successfully induced in 5.1 days in a medium containing 15 ​μM NAA while the maximum percentage of callus induction (77.78%) was obtained from petiole segments in a medium containing 10 ​μM NAA. Benzyl aminopurine at a concentration of 15 ​μM produced 1.33 shoots per nodal segment compared with 1.0 in the control. Indole butyric acid at a concentration of 10 ​μM increased root length (2.67 ​cm). The results showed a decrease in the browning intensity and an increase in the percentage of survivals in both leaf and petiole cultures (38.88%) and (61.11%) at 0.3 ​g/L activated charcoal compared to control (0% and 5.5%), respectively. Activated charcoal also reduced the total phenolic content of the leaf segment (9.51 ​mg/g) and petiole segment (2.06 ​mg/g). The in vitro produced rooted plantlets were successfully acclimatized in small pots containing peatmoss.

Major-effect quantitative trait locus qLKR4.1 encodes a phospholipase Dδ protein associated with low-K+ stress tolerance by promoting root length

qLKR4.1, controlling low K+ resistance in tomato, was fine-mapped to an interval of 67.5kb on chromosome A04, and one gene encoding phospholipase Dδ was identified as a candidate gene. In plants, changes in root length are an important morphological response to low K+ (LK) stress; however, the underlying genetics in tomato remain unclear. Here, we combined bulked segregant analysis-based whole-genome sequencing, single-nucleotide polymorphism haplotyping, and fine genetic mapping to identify a candidate gene as a major-effect quantitative trait loci (QTL), i.e., qLKR4.1, which was associated with LK tolerance due to increased root elongation in the tomato line JZ34. Through multiple analyses, we found that Solyc04g082000 is the most likely candidate for qLKR4.1, which encodes phospholipase Dδ (PLDδ). Increased root elongation under LK in JZ34 may be attributed to a non-synonymous single-nucleotide polymorphism in the Ca2+-binding domain region of this gene. Solyc04g082000 increases root length through its PLDδ activity. Silencing of Solyc04g082000Arg in JZ34 led to a significant decrease in root length compared with silencing of Solyc04g082000His allele in JZ18 under LK conditions. Mutation of a Solyc04g082000 homologue in Arabidopsis, pldδ, resulted in decreased primary root lengths under LK conditions, compared to the wild type. Transgenic tomato expressing the qLKR4.1Arg allele from JZ34 exhibited a significant increase in root length compared with the wild type expressing the allele from JZ18 under LK conditions. Taken together, our results confirm that the PLDδ gene Solyc04g082000 exerts important functions in increasing tomato root length and LK tolerance.

Genome-Wide Association Study for Root Morphology and Phosphorus Acquisition Efficiency in Diverse Maize Panels.

Maximizing soil exploration through modifications of the root system is a strategy for plants to overcome phosphorus (P) deficiency. Genome-wide association with 561 tropical maize inbred lines from Embrapa and DTMA panels was undertaken for root morphology and P acquisition traits under low- and high-P concentrations, with 353,540 SNPs. P supply modified root morphology traits, biomass and P content in the global maize panel, but root length and root surface area changed differentially in Embrapa and DTMA panels. This suggests that different root plasticity mechanisms exist for maize adaptation to low-P conditions. A total of 87 SNPs were associated to phenotypic traits in both P conditions at -log10(p-value) ≥ 5, whereas only seven SNPs reached the Bonferroni significance. Among these SNPs, S9_137746077, which is located upstream of the gene GRMZM2G378852 that encodes a MAPKKK protein kinase, was significantly associated with total seedling dry weight, with the same allele increasing root length and root surface area under P deficiency. The C allele of S8_88600375, mapped within GRMZM2G044531 that encodes an AGC kinase, significantly enhanced root length under low P, positively affecting root surface area and seedling weight. The broad genetic diversity evaluated in this panel suggests that candidate genes and favorable alleles could be exploited to improve P efficiency in maize breeding programs of Africa and Latin America.

Mn3 O4 Nanoparticles Alleviate ROS-Inhibited Root Apex Mitosis Activities to Improve Maize Drought Tolerance.

Poly (acrylic) acid coated Mn3O4 nanoparticles (PAA@Mn3 O4 nanoparticles (PMO, 11.02 nm, -28.93 mV)) are synthesized to investigate whether they can help to improve maize drought tolerance and the relevant mechanisms behind this. In planta experimental results show that under drought (15% PEG 6000, polyethylene glycol, mimicking drought stress, 96 h), compared with the control plants, 500 mg L-1 PMO (root application, 96 h) improves maize drought tolerance, showing an increase of root length (21.6%), shoot length (21.2%), fresh weight (7.8%) and total protein (67.2%) content. In addition, PMO significantly decreases the malondialdehyde (MDA) content by 74.7% in maize under drought, compared with the control group. Further, PMO treated maize root apex shows significantly increased mitotic index (MI, 35.5%), and decreased hydrogen peroxide (40.9%). Compared with the control under drought (15% PEG, 96 h), thr root apex of maize plants treated with PMO (500 mg L-1 , root application, 96 h) have significantly lower level of H2 O2 . Overall, the results show that PMO can alleviate drought-inhibited cell mitosis activities via maintaining ROS (reactive oxygen species) homeostasis. In this study, it is not only shown that PMO can be a good nano-regulator candidate to improve maize drought tolerance, but also that PMO has potential to modulate plant cell mitosis activities.

Synergistic effect of PGPR and PSB for alleviation of chromium toxicity in Vigna radiata (L.) R. Wilczek seedlings

The current investigation depicts the individual and synergistic effects of two important plant growth promoting microbial groups viz. Plant Growth Promoting Rhizobacteria (PGPR) and Phosphate Solubilizing Bacteria (PSB) in alleviating the phytotoxic impacts of chromium in Vigna radiata (L) R. Wilczek (green gram) seedlings. Cr6+ (100 ppm) treatment caused a stiff decline of about 44%, 72%, 68%, and 49% reduction in root and shoot length as well as leaf number and leaf area respectively as compared to control after 90 d of exposure. However, combined amendment with PGPR and PSB causes a significant amelioration of Cr toxicity though doubling the shoot length and leaf area with a 4 times increase in root length and leaf number after 90 d of growth. Total chlorophyll synthesis showed a 68% reduction in Cr6+ (100 ppm) which was ameliorated by combined treatments of PGPR and PSB. It showed a 123% increased total chlorophyll content than Cr6+ (100 ppm) whereas individual application of PGPR and PSB showed a 46% and 27% increase respectively. Combined application of PGPR and PSB with a toxic dose of Cr showed significant boosting alleviation ability and indicates its ameliorative role for abatement of Cr-induced toxicity.

Overexpression of OsERF106MZ promotes parental root growth in rice seedlings by relieving the ABA-mediated inhibition of root growth under salinity stress conditions

BackgroundRoots are essential for plant growth and have a variety of functions, such as anchoring the plant to the ground, absorbing water and nutrients from the soil, and sensing abiotic stresses, among others. OsERF106MZ is a salinity-induced gene that is expressed in germinating seeds and rice seedling roots. However, the roles of OsERF106MZ in root growth remain poorly understood.ResultsHistochemical staining to examine β-glucuronidase (GUS) activity in transgenic rice seedlings harboring OsERF106MZp::GUS indicated that OsERF106MZ is mainly expressed in the root exodermis, sclerenchyma layer, and vascular system. OsERF106MZ overexpression in rice seedlings leads to an increase in primary root (PR) length. The phytohormone abscisic acid (ABA) is thought to act as a hidden architect of root system structure. The expression of the ABA biosynthetic gene OsAO3 is downregulated in OsERF106MZ-overexpressing roots under normal conditions, while the expression of OsNPC3, an AtNPC4 homolog involved in ABA sensitivity, is reduced in OsERF106MZ-overexpressing roots under both normal and NaCl-treated conditions. Under normal conditions, OsERF106MZ-overexpressing roots show a significantly reduced ABA level; moreover, exogenous application of 1.0 µM ABA can suppress OsERF106MZ-mediated root growth promotion. Additionally, OsERF106MZ-overexpressing roots display less sensitivity to ABA-mediated root growth inhibition when treated with 5.0 µM ABA under normal conditions or exposed to NaCl-treated conditions. Furthermore, chromatin immunoprecipitation (ChIP)-qPCR and luciferase (LUC) reporter assays showed that OsERF106MZ can bind directly to the sequence containing the GCC box in the promoter region of the OsAO3 gene and repress the expression of OsAO3.ConclusionsOsERF106MZ may play a role in maintaining root growth for resource uptake when rice seeds germinate under salinity stress by alleviating ABA-mediated root growth inhibition.

Wheat derived glucuronokinase as a potential target for regulating ascorbic acid and phytic acid content with increased root length under drought and ABA stresses in Arabidopsis thaliana

Glucuronokinase (GlcAK) converts glucuronic acid into glucuronic acid-1-phosphate, which is then converted into UDP-glucuronic acid (UDP-GlcA) via myo-inositol oxygenase (MIOX) pathway. UDP-GlcA acts as a precursor in the synthesis of nucleotide-sugar moieties forming cell wall biomass. GlcAK being present at the bifurcation point between UDP-GlcA and ascorbic acid (AsA) biosyntheses, makes it necessary to study its role in plants. In this study, the three homoeologs of GlcAK gene from hexaploid wheat were overexpressed in Arabidopsis thaliana. The GlcAK overexpressing transgenic lines showed decreased contents of AsA and phytic acid (PA) as compared to control plants. Root length and seed germination analyses under abiotic stress (drought and abscisic acid) conditions revealed enhanced root length in transgenic lines as compared to control plants. These results indicate that the MIOX pathway might be contributing towards AsA biosynthesis as evident by the decreased AsA content in the GlcAK overexpressing transgenic Arabidopsis thaliana plants. Findings of the present study will enhance the understanding of the involvement of GlcAK gene in MIOX pathway and subsequent physiological effects in plants.

Mycobiota of Mexican Maize Landraces with Auxin-Producing Yeasts That Improve Plant Growth and Root Development.

Compared to agrochemicals, bioinoculants based on plant microbiomes are a sustainable option for increasing crop yields and soil fertility. From the Mexican maize landrace "Raza cónico" (red and blue varieties), we identified yeasts and evaluated in vitro their ability to promote plant growth. Auxin production was detected from yeast isolates and confirmed using Arabidopsis thaliana plants. Inoculation tests were performed on maize, and morphological parameters were measured. Eighty-seven yeast strains were obtained (50 from blue corn and 37 from red corn). These were associated with three families of Ascomycota (Dothideaceae, Debaryomycetaceae, and Metschnikowiaceae) and five families of Basidiomycota (Sporidiobolaceae, Filobasidiaceae, Piskurozymaceae, Tremellaceae, and Rhynchogastremataceae), and, in turn, distributed in 10 genera (Clavispora, Rhodotorula, Papiliotrema, Candida, Suhomyces, Soliccocozyma, Saitozyma Holtermaniella, Naganishia, and Aeurobasidium). We identified strains that solubilized phosphate and produced siderophores, proteases, pectinases, and cellulases but did not produce amylases. Solicoccozyma sp. RY31, C. lusitaniae Y11, R. glutinis Y23, and Naganishia sp. Y52 produced auxins from L-Trp (11.9-52 µg/mL) and root exudates (1.3-22.5 µg/mL). Furthermore, they stimulated the root development of A. thaliana. Inoculation of auxin-producing yeasts caused a 1.5-fold increase in maize plant height, fresh weight, and root length compared to uninoculated controls. Overall, maize landraces harbor plant growth-promoting yeasts and have the potential for use as agricultural biofertilizers.

Three-Dimensional Assessment of Radiographic Changes after Indirect Pulp Capping Using Silver Diamine Fluoride with or without Potassium Iodide in Young Permanent Teeth (12-Month RCT)

The aim of this study was to conduct a three-dimensional (3D) evaluation of radiographic changes after indirect pulp capping (IPC) with silver diamine fluoride (SDF) with or without potassium iodide (KI) and resin-modified glass ionomer cement (RMGIC) in deep carious young permanent molars using cone-beam computed tomography (CBCT). 108 first permanent molars with deep occlusal cavitated caries lesions, in forty-nine 6- to 9-year-old children, were randomly allocated to one of 3 groups (n = 36) and treated with SDF+KI, SDF, and RMGIC as IPC materials. CBCT scans were taken at 0 and 12 months to assess tertiary dentin formation (volume and grey level intensity), increase in root length, and pathological changes such as secondary caries, periapical radiolucency, internal resorption, and obliteration of the pulp. The 3D image analysis procedures were performed using ITK-SNAP and 3D Slicer CMF. Comparisons were made using analysis of variance with a fixed effect for treatment and random effects for patient and patient-by-treatment to account for within-patient correlations. A two-sided 5% significance level was used. There were no significant differences among the three groups regarding tertiary dentin volume (p = 0.712) and grey level intensity (p = 0.660), increase in root length (p = 0.365), prevention of secondary caries (p = 0.63), and periapical radiolucency (p = 0.80) in the analysed 69 CBCT scans. The study did not find differences among the groups regarding quality and quantity of tertiary dentin formed, increase in root length, absence of secondary caries, and other signs of failure as shown by CBCT. Clinical Significance: The results show no significant differences in radiographic outcomes (quality and quantity of tertiary dentin formed, increase in root length, absence of secondary caries, and other signs of failure) when using SDF+KI, SDF, and RMGIC in IPC. The results of this study can help guide treatment decision-making regarding use of SDF and SDF+KI as IPC materials in deep cavitated lesions.

Oxygenation promotes vegetable growth by enhancing P nutrient availability and facilitating a stable soil bacterial community in compacted soil

Soil compaction is a widespread phenomenon in intensive agriculture and can severely hamper root growth and crop yield. Hydrogen peroxide urea (UHP) has been employed as an effective measure for oxygenation in dryland systems. However, whether oxygenation via UHP could alleviate negative effects on vegetable growth induced by soil compaction is unknown. A pot experiment involving different soil bulk densities (1.2, 1.5, and 1.7 g cm−3) with oxygenation at different stages of development (seedling stage, mid-growth stage) was conducted in amaranth (A. mangostanus), with non-oxygenation at different soil bulk densities as a control. Increased soil compaction affected vegetative growth of both the shoot and root system of amaranth and caused yield reduction. Oxygenation in topdressing significantly improved soil O2 supply until the harvest period, imparted 17.9–20.4 % additional O2 to soils. Increased O2 supply alleviated soil compaction stress, and amaranth yield increased by 5.50–16.1 % at the same soil bulk density compared with control, respectively. Oxygenation during the mid-growth stage had a superior effect on vegetable growth compared to oxygenation at the seedling stage, coincident with the higher oxygen demand during mid-growth in amaranth. Oxygenation promoted root growth in compacted soil, and increased root length by 76.3 % at a soil bulk density of 1.5 g cm−3 and 74.7 % at a bulk density of 1.7 g cm−3 compared with control. The alleviatory effect on the root system can be linked to increased root catalase activity and decreased malondialdehyde content. Oxygenation furthermore increased phosphorus (P) bioavailability by increasing both phosphatase activity and the relative abundance of phosphate-solubilizing bacteria (Firmicutes and Proteobacteria), with an increase in DGT-P by 10.5–23.6 % compared to control. The soil bacterial co-occurrence network at a soil bulk density of 1.5 g cm−3 with oxygenation was more similar to 1.2 g cm−3 soil compaction with oxygenation, which possessed most complex and the proportion of connectors, but was dissimilar from 1.7 g cm−3 soil compaction with oxygenation, which was less stable microbial network structure. Improvement of O2 content could build a healthy and stable rhizosphere bacterial community, and increased the proportion of important nodes in the network, which was conducive to the collaborative development of microorganisms to face compaction stress. And bacterial community structure with oxygenation in compacted soil could recovery to near normal microbiology community structure. The research provides a theoretical and technical framework for the development of strategies that can maximize crop yield in compacted soil.