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PubMed1974

Cell wall and protoplast isoperoxidases in relation to injury, indoleacetic Acid, and ethylene effects.

In tobacco (Nicotiana Tabacum) pith, sweet potato (Ipomoea batatas), and carrot (Daucus carota) storage roots, differences were found between cell wall and protoplast peroxidases in their isoenzyme patterns, activity, and reaction to tissue injury.In the pith of elongating tobacco internodes, 90% of total activity was associated with the walls, 80% of which was due to the ionically and covalently bound fractions. With senescence, the increase in activity occurred mainly in the protoplast and the free fraction in the walls. The major protoplast isoperoxidases formed the free wall fraction, and the minor ones formed the wall bound fractions. The minor isoperoxidases were the only ones whose activities were affected by cut injury. Neither senescence nor injury caused qualitative changes in the cell isoperoxidase pattern. In the potato root cells, the isoperoxidases were also distinctive in their distribution and in their reactions to injury as well as to ethylene.In potato and carrot roots, the wall fractions contributed 30 and 95%, respectively, to total peroxidase activity. The injury-induced increase in peroxidase activity occurred mainly in the protoplast of tobacco pith and potato roots and almost entirely in the ionically bound fraction of the walls in carrot roots. Ethylene stimulated peroxidase development in potato roots, especially in the protoplast, but had no effect in either tobacco pith or carrot roots. Ethylene did not affect the inhibiting action of indoleacetic acid on peroxidase activity in tobacco pith, nor did indoleacetic acid significantly affect the stimulating action of ethylene in potato roots.Actinomycin D inhibited the injury-dependent development of peroxidase in tobacco pith, stimulated the injury- and ethylene-dependent peroxidase development in potato root, and had no effect on peroxidase development in carrot root. Cycloheximide prevented the increase in peroxidase activity in tobacco pith and potato root, but not in the carrot root. Thus, the enhancement of peroxidase activity resulted from either enzyme activation exclusively or from enzyme synthesis. RNA synthesis seems to be only indirectly related to isoperoxidase synthesis caused by injury or ethylene.

Journal Article↗
PubMed2000

Identification of rice varieties with high tolerance or sensitivity to lead and characterization of the mechanism of tolerance.

Pb inhibits plant growth. To study Pb tolerance in rice (Oryza sativa), we screened 229 varieties for Pb tolerance or sensitivity. Three-day-old seedlings were treated for 12 d with 20 microM Pb solution. Based on the dry weight of the root, three Pb-tolerant (var CH-55, var KH-2J, var Kumnung) and three Pb-sensitive (var Aixueru, var C-9491, var Milyang23) rice varieties were selected. The root biomasses of the tolerant varieties were approximately 10-fold higher than those of the sensitive ones. The greatest morphological difference between the two groups was in the growth of the adventitious roots, as tolerant lines were able to develop adventitious roots after 6 d of Pb treatment, whereas sensitive ones did not develop any even after 15 d. The growth of adventitious roots in the tolerant varieties was dependent on a mechanism, whereby Pb was altered to a form that cannot be taken up by the tissue, because (a) the solution in which the tolerant varieties of rice had grown still contained Pb but nevertheless did not affect the root growth of new rice seedlings, and (b) the adventitious roots of tolerant seedlings developed in Pb solution contained little Pb. The oxalate content in the root and root exudate increased upon Pb treatment in the tolerant varieties, whereas the opposite was observed for the sensitive ones. Oxalate added to the growth solution ameliorated the inhibition of root growth by Pb. These results suggest that compounds such as oxalate secreted from the root may reduce the bio-availability of Pb, and that this may constitute an important Pb tolerance mechanism in the tolerant rice varieties studied here.

Adaptation, Physiological↗
PubMedDate not supplied

In vitro evaluation of secondary caries development in enamel and root dentin around luted metallic restoration.

Materials that release fluoride have been recommended for patients with high caries risk, but there is no conclusive evidence of their effect on fixed prostheses abutments. This study evaluated the influence of a resin-modified glass-ionomer cement on in vitro caries development in enamel and root dentin around metallic restoration. The cervical portion of 12 human third molars were sectioned in four blocks that were randomly divided into four Groups (n = 12; 1 block from each tooth/group): ZP (restoration + zinc phosphate cement), GI (restoration + resin-modified glass-ionomer cement), C1 (no restoration and no pH cycling), and C2 (no restoration and pH cycling). In ZP and GI, metallic restorations were luted at the crown-root junction. ZP, GI and C2 were submitted to a pH-cycling model. All blocks were sectioned, embedded and polished. Enamel and root dentin demineralization were evaluated through cross-sectional microhardness Knoop measures at 20 to 80 microns of depth (from the outer surface) and at 20 to 220 microns of distance from the cavity margins. Mineral loss values were calculated from Knoop hardness numbers. Data were analyzed by ANOVA, Tukey's test and regression analysis. Groups ZP, GI and C2 showed demineralization in relation to C1, which was more superficial in enamel than in root dentin. In root dentin, mineral loss in ZP and GI was smaller than in C2. Distance from the cavity margins was not significant. There was no difference between resin-modified glass-ionomer cement and zinc phosphate cement regarding artificial secondary caries development in both dental substrates.

Analysis of Variance↗
PubMed2001

Genotypic differences in the presence of hairs on roots and gynophores of peanuts (Arachis hypogaea L.) and their significance for phosphorus uptake.

Root hairs substantially increase the surface area of plant roots with positive effects for phosphorus (P) uptake, but the ability of peanuts to form root hairs has been questioned. The aim was to examine hair development on roots and gynophores of a variety of peanut genotypes and to relate genotypic differences in hair formation to differences in P uptake. Five out of eighteen genotypes completely lacked hairs on both organs whereas others consistently developed hairs on roots and gynophores, although with considerable variation in hair density. The ability to form root hairs as well as root hair density concurred with the presence and density of hairs on gynophores, suggesting a possible connection between both developmental processes. The contribution of root hairs to P uptake was studied in three genotypes differing in hair density. The final amount of P taken up by roots did not differ between genotypes but two distinct P uptake strategies could be identified. The genotype lacking root hairs maintained P uptake due to the development of a large root system whereas densely covered roots of genotype 'Wasedairyu' were three times as efficient in extracting P from a P-deficient soil. Furthermore P uptake through gynophores contributed about 20% to the total P uptake of Wasedairyu but only insignificant amounts to other genotypes. The ability to form hairs on roots and gynophores can therefore be seen as an adaptation to low P availability and if combined with a large root system, could substantially increase the tolerance of peanuts to P deficiency.

Arachis↗
PubMed1985

Development and enzyme activity of protein bodies in proteinoplasts of tobacco root cells.

The development of protein bodies in proteinoplasts of tobacco (Nicotiana tabacum L. var. Wis. 38) roots was investigated with TEM, HVEM, and enzyme cytochemistry. These plastids contain a three-dimensional network of fenestrated tubules which originate from invaginations of the inner membrane of the plastid envelope. Elaboration of the network occurs in parallel with cell differentiation: slender tubules common to plastids in meristematic cells undergo dilation as protein accumulates during cell differentiation; proteinoplasts of vacuolate and root cap cells usually contain a large protein body. The contents of the peripheral tubules, originating from the inner membrane, are less electron dense than the tubules making up the central network. Localized dilations within the tubular network result in the formation of dense spheroidal structures, protein bodies, apparently as a result of continued protein accumulation via tubules connecting to the central network. Protein might be imported from segments of rough ER attached to or apposed to the outer membrane of the proteinoplast envelope. The presence of catalase (E.C. 1.11.1.6), peroxidase (E.C. 1.11.1.7), and cytochrome oxidase (E.C. 1.9.3.1) was demonstrated by cytochemistry with diaminobenzidine (DAB) as substrate. Oxidized DAB was found in protein bodies after incubation in each of the specific reaction media. While aminotriazole and sodium azide inhibited oxidation of DAB by catalase and peroxidase, respectively, only potassium cyanide completely inhibited oxidation of DAB in protein bodies. We conclude that protein bodies of proteinoplasts in tobacco roots are not sites for storage of protein, rather protein bodies contain heme protein(s) with strong oxidase activity that may convey a specific function to proteinoplasts.

Enzymes↗
PubMed1983

Proteolytic Activity in Soybean Root Nodules : Activity in Host Cell Cytosol and Bacteroids throughout Physiological Development and Senescence.

Root nodules were harvested from chamber-grown soybean (Glycine max L. Merrill cv Woodworth) plants throughout development. Apparent nitrogenase activity (acetylene reduction) peaked before seeds began to develop, but a significant amount of activity remained as the seeds matured. Nodule senescence was defined as the period in which residual nitrogenase activity was lost. During this time, soluble protein and leghemoglobin levels in the host cell cytosol decreased, and proteolytic activity against azocasein increased. Degradative changes were not detected in bacteroids during nodule senescence. Total soluble bacteroid protein per gram of nodule remained constant, and an increase in proteolytic activity in bacteroid extracts was not observed. These results are consistent with the view that soybean nodule bacteroids are capable of redifferentiation into free-living bacteria upon deterioration of the legume-rhizobia symbiosis.

Journal Article↗
PubMed1999

Survival and complication free survival in Marfan's syndrome: implications of current guidelines.

OBJECTIVE: To evaluate survival and complication free survival in patients with Marfan's syndrome and to assess the possible influence of recently revised guidelines for prophylactic aortic root replacement in these patients. METHODS: 130 patients who had been attending one institution over 14 years were evaluated. Kaplan-Meier analysis was performed in 125 patients who did not present with aortic root dissection as the first sign of Marfan's syndrome, with the end points: death, aortic root dissection, and prophylactic aortic root replacement after diagnosis. In the patients developing aortic root dissection, current guidelines for prophylactic aortic root replacement were retrospectively applied to investigate the number of dissections that could theoretically have been prevented. The guidelines were: (1) aortic root diameter >/= 55 mm, (2) positive family history of aortic dissections and aortic root diameter >/= 50 mm, and (3) aortic root growth >/= 2 mm/year. Outcomes following emergency surgery (15 patients) and prophylactic surgery of the aortic root (30 patients) were compared. RESULTS: Five and 10 year survival after diagnosis was 95% and 88%, and the five and 10 year complication free survival was 78% and 66%, respectively. Thirteen patients developed dissection, 30 underwent prophylactic repair, and 82 had an uncomplicated course. Eleven dissections could theoretically have been prevented by application of the current guidelines. Five year survival following emergency and prophylactic repair of the aortic root was 51%, and 97%, respectively. CONCLUSIONS: Survival in the Marfan's syndrome in the past 14 years seems satisfactory; with application of current guidelines, it has probably even improved. However, because of the high fatality rate in Marfan patients developing aortic root dissection, more extensive screening for Marfan's syndrome and a search for additional risk factors are desirable.

Adolescent↗
PubMed1985

The development of the relationship between dorsal root afferents and motoneurons in the larval bullfrog spinal cord.

The relationship of dorsal root afferents to motoneuron somata and dendrites was studied by labelling dorsal and ventral roots of the tadpole lumbar enlargement with HRP at different stages of hindlimb development. Procedures were used which allowed for sequential light and electron microscopic analysis to determine whether close appositions between labelled elements represented synaptic contacts. Lateral motor column (LMC) motoneuron dendrites grow first into the lateral funiculus, and later begin arborizing within the spinal gray, concurrent with the arrival of developing dorsal root afferent fibers. Mature-appearing synaptic contacts between dorsal root afferents and motoneuron dendrites are established first on distal dendrites, and are observed on progressively more proximal dendrites as hindlimb development proceeds. Migrating motoneurons were also labelled in some animals. Distinct dorsal and ventral migratory pathways were noted; cells migrating dorsally were contacted by developing dorsal root afferents. Migrating motoneurons were associated with radially oriented processes, and were often closely apposed to other cells. The coincident development of dorsal root projections and the motoneuron dendrites which these fibers innervate in the adult, as well as the interaction between these two systems during cell migration, suggest that these two systems may be interdependent in establishing their normal relationship during development.

Animals↗
PubMedDate not supplied

Effect of saliva composition on experimental root caries.

The aim of this study was to determine the effect of saliva composition on caries lesion development independently of the flow rate of unstimulated whole saliva (UWS) and other caries-related variables such as lesion progression time, oral hygiene level, and fluoride exposure. We hypothesized that this could be done by developing experimental root caries under carefully controlled conditions in situ in test subjects with UWS flow rates within a narrow window of normalcy. Fifteen female and 5 male subjects (66 +/- 6 years) were selected for the study according to their UWS flow rates between 0.2 and 0.4 ml/min. All subjects developed experimental root caries lesions during a 62-day period in which UWS as well as stimulated whole saliva (SWS) were repeatedly collected and analysed for flow rate, pH, buffer capacity, inorganic, and organic composition. Caries lesion development was determined by quantitative microradiography. The mean UWS flow rate was 0.30 +/- 0.05 ml/min. Significant negative correlations were obtained between UWS total phosphate concentration and mineral loss (DeltaZ; r(s) = -0.72, p < 0.001) and UWS total protein concentration and DeltaZ (r(s) = -0.70, p < 0.01). SWS and its constituents had only limited or no effect on DeltaZ. Qualitative UWS protein analysis (SDS-PAGE) revealed that subjects with low DeltaZ values had broader and more stained amylase bands than subjects with high DeltaZ values. These findings were confirmed quantitatively by HPLC. We conclude that, within a group of subjects with normal UWS flow rates, the UWS composition was more important for caries lesion development than the SWS composition. Furthermore, high UWS concentrations of phosphate, protein, and amylase were caries-protective.

Aged↗
PubMed2003

Hedgehog signaling is directly required for the development of zebrafish dorsal root ganglia neurons.

Hedgehog (Hh) signal transduction is directly required in zebrafish DRG precursors for proper development of DRG neurons. Zebrafish mutations in the Hh signaling pathway result in the absence of DRG neurons and the loss of expression of neurogenin1 (ngn1), a gene required for determination of DRG precursors. Cell transplantation experiments demonstrate that Hh acts directly on DRG neuron precursors. Blocking Hh pathway activation at later stages of embryogenesis with the steroidal alkaloid, cyclopamine, further reveals that the requirement for a Hh signal response in DRG precursors correlates with the onset of ngn1 expression. These results suggest that Hh signaling may normally promote DRG development by regulating expression of ngn1 in DRG precursors.

Animals↗
PubMed1998

Root-surface caries in rats and humans: inhibition by a non-antimicrobial property of tetracyclines.

The incidence of root caries has been found to increase as the population ages and as edentulism becomes less prevalent due to improved dental awareness and care, and as exposure of roots due to gingival recession has also increased in the elderly. The mechanism of root caries is thought to be mediated by both bacterial and mammalian proteases produced by plaque and the periodontal tissues, respectively. In the current study, a rat model of periodontal disease was used in which gnotobiotic rats were infected intra-orally with a periodontal pathogen (P. gingivalis). Infecting the rats with P. gingivalis increased the collagenase activity in the gingival tissue in association with severe alveolar bone loss. Treating P. gingivalis-infected rats with doxycycline or CMT-1 prevented the destruction of the periodontium by MMPs, thus preventing exposure of roots to subgingival bacterial plaque and host tissue collagenases and the subsequent development of root caries. In addition, a low-dose doxycycline (LDD, 20 mg bid, non-antimicrobial dose) for 3 months was used in humans predisposed to increased root caries as the result of heavy use of smokeless (chewing) tobacco, causing gingival recession, subgingival plaque accumulation with Gram-negative bacteria, increased gingival crevicular fluid flow (GCF), and elevated GCF collagenase. Daily administration of LDD in smokeless tobacco patients reduced the GCF collagenase and prevented the further development of root caries.

Adult↗
PubMed1979

Development of the nitrogen-fixing and protein-synthesizing apparatus of bacteroids in pea root nodules.

Some aspects of root nodule development of Pisum sativum inoculated with Rhizobium leguminosarum were examined. 1. Nitrogenase activity (measured as acetylene reduction) appears to be preceded by leghemoglobin synthesis (measured immunologically). 2. Syntheses of component I and component II of nitrogenase are not strictly coordinated. Synthesis of component I starts before component II. 3. Plant and bacteroid protein synthesis (measured by [35S]sulfate labeling) in root nodules declines rapidly during nodule development. Corresponding with this decline is a decrease in quantity and quality of rRNA.

Fabaceae↗
PubMed1999

Development of inflammatory hypersensitivity and augmentation of sodium channels in rat dorsal root ganglia.

The development of thermal allodynia in relationship to sodium channel augmentation in dorsal root ganglia (DRGs) was studied in albino rats. Paw withdrawal latencies were measured hourly following complete Freund's adjuvant (CFA) injections. Sodium channels were demonstrated with immunocytochemistry. Sustained minimum latencies were attained between 10 and 12 h post-injection. Sodium channel labeling began to increase at 23 h post-injection and reached maximum levels by 24 h. Thermal hypersensitivity is thus established 12 h before sodium channel augmentation can be demonstrated.

Animals↗
PubMed1978

Studies on hexachlorophene-induced myelin lesions in the trigeminal root transitional region in developing and adult mice.

Hexachlorophene (HCP)-induced intramyelinic vacuolation was studied in the transitional region of the trigeminal root of suckling and adult mice. HCP produced an extensive vacuolation in the central compartment of the region in both suckling and adult mice, while in the peripheral compartment myelin lesions were only seen in mice less than 16 days of age. Gas chromatographic measurements showed that in suckling mice the blood concentration of HCP decreased with age, apparently reflecting a faster elimination of HCP from the blood. By substantially increasing the HCP dose, higher blood concentrations were obtained in adult than less the 16-day-old mice; in spite of this, PNS myelin changes occurred only in the latter. Thus, by observing the HCP effect on the transitional region, where CNS and PNS directly meet, it is concluded that CNS of both suckling and adult mice is more severely effected by HCP than PNS, and that the reaction of the PNS myelin is age-dependent during the period of myelinogenesis; it is particularly vulnerable to a cytotoxic edema inducing substance.

Age Factors↗
PubMed1993

Transport of Water and Solutes across Maize Roots Modified by Puncturing the Endodermis (Further Evidence for the Composite Transport Model of the Root).

The effects of puncturing the endodermis of young maize roots (Zea mays L.) on their transport properties were measured using the root pressure probe. Small holes with a diameter of 18 to 60 [mu]m were created 70 to 90 mm from the tips of the roots by pushing fine glass tubes radially into them. Such wounds injured about 10-2 to 10-3% of the total surface area of the endodermis, which, in these hydroponically grown roots, had developed a Casparian band but no suberin lamellae. The small injury to the endodermis caused the original root pressure, which varied from 0.08 to 0.19 MPa, to decrease rapidly (half-time = 10-100 s) and substantially to a new steady-state value between 0.02 and 0.07 MPa. The radial hydraulic conductivity (Lpr) of control (uninjured) roots determined using hydrostatic pressure gradients as driving forces was larger by a factor of 10 than that determined using osmotic gradients (averages: Lpr [hydrostatic] = 2.7 x 10-7 m s-1 MPa-1; Lpr [osmotic] = 2.2 x 10-8 m s-1 MPa-1; osmotic solute: NaCl). Puncturing the endodermis did not result in measurable increases in hydraulic conductivities measured by either method. Thus, the endodermis was not rate-limiting root Lpr: apparently the hydraulic resistance of roots was more evenly distributed over the entire root tissue. However, puncturing the endodermis did substantially change the reflection ([sigma]sr) and permeability (Psr) coefficients of roots for NaCl, indicating that the endodermis represented a considerable barrier to the flow of nutrient ions. Values of [sigma]sr decreased from 0.64 to 0.41 (average) and Psr increased by a factor of 2.6, i.e. from 3.8 x 10-9 to 10.1 x 10.-9 m s-1(average). The roots recovered from puncturing after a time and regained root pressure. Measurable increases in root pressure became apparent as soon as 0.5 to 1 h after puncturing, and original or higher root pressures were attained 1.5 to 20 h after injury. However, after recovery roots often did not maintain a stable root pressure, and no further osmotic experiments could be performed with them. The Casparian band of the endodermis is discontinuous at the root tip, where the endodermis has not yet matured, and at sites of developing lateral roots. Measurements of the cross-sectional area of the apoplasmic bypass at the root tip yielded an area of 0.031% of the total surface area of the endodermis. An additional 0.049% was associated with lateral root primordia. These areas are larger than the artificial bypasses created by wounding in this study and may provide pathways for a "natural bypass flow" of water and solutes across the intact root. If there were such a pathway, either in these areas or across the Casparian band itself, roots would have to be treated as a system composed of two parallel pathways (a cell-to-cell and an apoplasmic path). It is demonstrated that this "composite transport model of the root" allows integration of several transport properties of roots that are otherwise difficult to understand, namely (a) the differences between osmotic and hydrostatic water flow, (b) the dependence of root hydraulic resistance on the driving force or water flow across the root, and (c) low reflection coefficients of roots.

Journal Article↗
PubMed1988

The effect of desalivation on coronal and root surface caries in rats.

Although the presence of coronal caries is declining in much of the Western Hemisphere, the prevalence of root surface caries is likely to increase as teeth are retained longer than heretofore. At the same time, an increasing number of the population suffer from dry mouth as a result of taking prescription drugs, with an apparent concomitant increased susceptibility to root surface caries. This study attempted to develop an animal model which would aid in the exploration of the effects of desalivation and the development of root surface caries. Animals were desalivated, infected with Actinomyces viscosus and Streptococcus mutans (sobrinus) 6715, and fed a cariogenic diet. Coronal caries developed rapidly in the animals; sufficient disease was present after two weeks to permit evaluation of potential therapeutic agents. Alveolar bone loss and root surface lesions developed in three to four weeks. S. mutans (sobrinus) and A. viscosus established readily in all animals; however, as the investigation progressed, populations of the latter declined, possibly because of the highly acidogenic environment. This model will facilitate investigation of the influence of hyposalivation and help in the exploration of agents to alleviate the adverse effects of salivary gland dysfunction.

Actinomyces viscosus↗
PubMed2026

The genome of Thesium ramosoides (Santalales) reveals evolutionary dynamics associated with parasitism and alpine adaptation.

Plant species adapting to complex environments experience contrasting selection pressures that drive the expansion and contraction of different gene families. However, few studies have investigated simultaneous genomic responses to such diverse selective forces. Here, we generate a high-quality genome assembly for the hemiparasitic plant Thesium ramosoides, the first for the largest genus in the Santalales, and explore the genomic basis underlying the evolution of parasitism and alpine adaptation. Unlike many other parasitic plants, the Thesium genome has not undergone additional rounds of whole-genome duplication, making it particularly tractable for studying gene family evolution. Our analyses reveal substantial loss of photosynthesis-related genes and contraction of biotic defense gene families, likely reflecting adaptation to a hemiparasitic lifestyle and reduced pathogen pressure at high altitudes. The absence of key root hair development genes correlates with the degenerate root hair phenotype observed in this species. Furthermore, hallmarks of high-altitude adaptation include the expansion of gene families involved in responses to hypoxia. Notably, expansion of gene families associated with meristem development is consistent with the presence of below-ground crown buds that enable rapid regeneration after mountain fires. Unexpectedly, we detected tandem duplication and diversification of the strigolactone receptor gene D14, which regulates secondary shoot formation, but not of its ancestral paralog KAI2, which mediates seed germination in response to the smoke-derived compound karrikin. This finding suggests divergent signaling mechanisms underlying fire adaptation across different parasitic plant lineages. By integrating time-series transcriptomic data, we propose a post-fire "defense first, repair later, recovery last" model, in which resources are reallocated from immediate defense to rapid repair and ultimately to long-term recovery, to explain the adaptation of T. ramosoides to fire-prone habitats. Our study provides critical insights into the complex and contrasting genomic dynamics that drive adaptation to multiple co-occurring selection pressures.

Genome, Plant↗
PubMed2005

Control of root cap formation by MicroRNA-targeted auxin response factors in Arabidopsis.

The plant root cap mediates the direction of root tip growth and protects internal cells. Root cap cells are continuously produced from distal stem cells, and the phytohormone auxin provides position information for root distal organization. Here, we identify the Arabidopsis thaliana auxin response factors ARF10 and ARF16, targeted by microRNA160 (miR160), as the controller of root cap cell formation. The Pro(35S):MIR160 plants, in which the expression of ARF10 and ARF16 is repressed, and the arf10-2 arf16-2 double mutants display the same root tip defect, with uncontrolled cell division and blocked cell differentiation in the root distal region and show a tumor-like root apex and loss of gravity-sensing. ARF10 and ARF16 play a role in restricting stem cell niche and promoting columella cell differentiation; although functionally redundant, the two ARFs are indispensable for root cap development, and the auxin signal cannot bypass them to initiate columella cell production. In root, auxin and miR160 regulate the expression of ARF10 and ARF16 genes independently, generating a pattern consistent with root cap development. We further demonstrate that miR160-uncoupled production of ARF16 exerts pleiotropic effects on plant phenotypes, and miR160 plays an essential role in regulating Arabidopsis development and growth.

Arabidopsis↗