The study of allelic variations affecting organogenic capacity is not only relevant for manipulating plant traits but also to understand the fundamental mechanisms involved in plant development. ...Here, we report the characterization of three tomato (
Solanum lycopersicum
) loci (
RG3C, RG7H
and
RG8F
) whose alleles from its wild relative
Solanum pennellii
enhance
in vitro
shoot and root regeneration.
S. pennellii
alleles were introgressed into tomato cv. Micro-Tom (MT), creating near-isogenic lines. We evaluated the time taken for shoot induction and acquisition of competence by quantifying organogenesis after transferring explants, respectively, from the shoot-inducing medium (SIM) to the basal medium (BM) and from root-inducing medium (RIM) to the SIM. Concomitantly, we monitored the expression of key developmental genes. MT-
Rg3C
and MT-
Rg7H
started shoot induction, respectively, at 48 and 24 h earlier than MT and MT-
Rg8F
, while MT-
Rg3C
and MT-
Rg8F
acquired competence 24 h before MT. The impact of MT-
Rg3C
and MT-
Rg8F
in the acquisition of competence to assume different fates is consistent with their effect enhancing both shoot and root regeneration. MT-
Rg7H
seems to affect shoot induction specifically, which is in agreement with the enhanced expression of the shoot-related genes
WUSCHEL
and
SHOOT MERISTEMLESS
. Phenotypic characterization of greenhouse-grown plants showed that
Rg3C
has increased branching when compared to MT. Conversely, the normal branching observed in MT-
Rg7H
and MT-
Rg8F
indicates that adventitious in vitro shoot formation and ex vitro axillary bud formation/outgrowth are induced by different genetic pathways. These natural variations are thus useful for breeding highly regenerating varieties without undesirable effects on plant architecture.
Environmental benefits from bioenergy production derived from sugarcane crop residues (straw) can be lost by soil organic matter depletion resulting from excessive straw removal rates from fields. ...Soil organic carbon stock is the core for sustaining soil health, supporting nutrient cycling, and sequestering carbon dioxide. To find out that how much sugarcane straw can be removed from the field to produce bioenergy without changes in soil C concentrations, we investigated effects of straw removal rates (total, moderate, and no removal of sugarcane straw) on soil carbon and nitrogen fractions in an Oxisol and an Ultisol in southeastern Brazil for two years. Soil C and N fractions were affected by increased rates of straw removal at the second year. In the Oxisol, total straw removal decreased labile and microbial-C by ~30% and soil C stock by 20% compared to no straw removal. No removal decreased microbial-N and total N stock by ~15% and ~20%, respectively. In the Ultisol, no straw removal resulted in increases in C stock by >10% and labile and microbial-C by ~20% related to total straw removal. Total straw removal showed more microbial-N (~10%) and total-N stock (~25%) compared to no straw removal. The moderate straw removal intensity (i.e., 8 to 10 Mg ha−1 of straw) may control the straw-C release to soil by straw decomposition. This study suggests that excessive straw removal rates should be avoided, preventing SOM depletion and consequently, soil health degradation. Moderate straw removal seems to be a promising strategy, but long-term soil C monitoring is fundamental to design more sustainable straw management and bioenergy production systems.
The objective of this study was to evaluate the effect of a PGF2α-analogue (PGF) on ovulation and pregnancy rates after timed artificial insemination (TAI) in cattle. In experiment 1, crossbred ...dual-purpose heifers, in a crossover design (3 × 3), were given an intravaginal progesterone-releasing insert (controlled internal drug release CIDR) plus 1 mg estradiol benzoate (EB) intramuscularly (im) and 250 μg of a PGF-analogue im on Day 0. The CIDR inserts were removed 5 days after follicular wave emergence, and the heifers were randomly divided into three treatment groups to receive the following treatments: (1) 1 mg of EB im (EB group, n = 13); (2) 500 μg of PGF im (PG group, n = 13); or (3) saline (control group, n = 13), 24 hours after CIDR removal. Ovulation occurred earlier in EB (69.81 ± 3.23 hours) and PG groups (73.09 ± 3.23 hours) compared with control (83.07 ± 4.6 hours; P = 0.01) after CIDR removal. In experiment 2, pubertal beef heifers (n = 444), 12 to 14 months of age were used. On Day 0, the heifers were given a CIDR insert plus 2 mg EB im. On Day 9, the CIDR was removed and the heifers were given 500 μg of PGF im. Heifers were randomly assigned into one of three treatment groups: (1) 1 mg of EB (EB group; n = 145); (2) 500 μg of PGF (PG group; n = 149), both 24 hours after CIDR removal; or (3) 600 μg of estradiol cypionate (ECP group; n = 150) at CIDR removal. Timed artificial insemination occurred 48 hours after CIDR removal in the ECP group and 54 hours in the PG and EB groups. The percentage of heifers ovulating was higher in the PG group compared with the other groups (P = 0.08). However, the pregnancy rates did not differ among groups (47.6%, 45%, and 46.6%, for EB, PG, and ECP, respectively; P = 0.9). In experiment 3, 224 lactating beef cows, 40 to 50 days postpartum with 2.5 to 3.5 of body condition score were treated similarly as described in experiment 2, except for the ECP group, which was excluded. The treatments were as follows: 1 mg EB (EB group; n = 117) or 500 μg PGF (PG group; n = 107), 24 hours after CIDR removal. The calves were temporarily separated from their dams from Days 9 to 11. No difference was detected on the pregnancy rate between the EB and PG groups (58.1% vs. 47.6%, respectively; P = 0.11). Taken together, the combined results suggested that PGF2α could be successfully used to induce and synchronize ovulation in cattle undergoing TAI, with similar pregnancy rates when compared with other ovulatory stimuli (ECP and EB).
In dilute aqueous solution unimers of Pluronic F127 associate to form micelles. In more concentrated solution, micelles pack to form high-modulus gels. Our interest is the effect of addition of 10–30 ...wt % low molecular weight PPG400 on the micellization and gelation of solutions of F127. DLS was used to determine the apparent size of the micelles (r h,app). The critical micelle concentration (cmc) using the dye solubilization method of F127 in PPG400 solutions was studied. Visual observation was carried out to detect gel formation in concentrated solutions and the onset of clouding and turbidity, as the temperature was raised. Oscillatory rheometry was used to confirm the formation of high-modulus gels and provide values of elastic moduli (G′max) over a wide temperature range. SAXS was used to determine gel structure. Our results for the hydrophobic adduct PPG400 were compared with literature values for the hydrophilic adduct PEG6000.
Global warming can intensify the soil organic matter (SOM) turnover, damaging soil health. Crop residues left on the soil are important to maintain a positive SOM budget and nutrient cycling. But, ...sugarcane (
Saccharum officinarum
) straw has been removed from the field for bioenergy purposes. We hypothesize that global warming, together with straw removal, will negatively impact Brazil’s ethanol carbon footprint. Thus, we conducted an experiment under controlled conditions to evaluate the impacts of warming and straw removal on greenhouse gas (GHG) emissions, soil carbon and nitrogen storage, and nutrient cycling. Two soils (Rhodic Acrisol and Eutric Nitisol) were tested with three rates of sugarcane straw removal (no removal (NR): equivalent to 12 Mg ha
−1
; medium removal (MR): 6 Mg ha
−1
; and total removal (TR): bare soil) and submitted to two temperatures (24 °C and 30 °C) and soil moistures (30% and 50%). Straw decomposition was stimulated by lower rates of straw removal, resulting in increases on carbon dioxide (CO
2
) emissions between 5 to 14 times, and N
2
O between 25 and 40%. There were no significant methane (CH
4
) fluxes. Soil carbon and nitrogen did not change due to straw removal, yet labile carbon fractions (living and non-living) were highly impacted, causing reductions of 15 to 40% on the carbon management index (CMI). Furthermore, straw removal reduced nutrient cycling between 10 and 30%. Overall, in a scenario of warming, our findings point to an intensification of SOM dynamic, resulting in increases of 35% on the GHG emissions and a CMI reduction by 20%. In practical terms, at least 6 Mg ha
−1
of straw should be left in the field, guaranteeing raw-material for bioenergy, without causing major impacts on the GHG emission and soil attributes.
Propranolol (PPN) is a therapeutic option for the treatment of infantile hemangiomas. This study aimed at the development of nanoemulsion (NE) containing 1% PPN, characterization of the system, and ...safety studies based on ex vivo permeation, cytotoxicity, and biodistribution in vivo.
The formulation was developed and characterized in relation to the droplet size, polydispersity index (PDI), pH, zeta potential, and electronic microscopy. Ex vivo permeation studies were used to evaluate the cutaneous retention of PPN in the epidermis and dermis. Cytotoxicity studies were performed in fibroblasts, macrophages, and keratinocytes. In vivo biodistribution assay of the formulations was performed by means of labeling with technetium-99m.
NE1 exhibited droplet size of 26 nm, PDI <0.4, pH compatible with the skin, and zeta potential of -20 mV, which possibly contributes to the stability. Electron microscopy showed that the NE presented droplets of nanometric size and spherical shape. NE1 provided excellent stability for PPN. In the ex vivo cutaneous permeation assay, the NE provided satisfactory PPN retention particularly in the dermis, which is the site of drug action. In addition, NE1 promoted cutaneous permeation of the PPN in small amount. In vivo biodistribution showed that the radiolabeled formulation remained in the skin and a small amount reached the bloodstream. NE1 presented low cytotoxicity to fibroblasts, macrophages, and keratinocytes in the concentrations evaluated in the cytotoxicity assay.
We concluded that the formulation is safe for skin administration; however, cutaneous irritation studies should be performed to confirm the safety of the formulation before clinical studies in patients with infantile hemangiomas.
The sugarcane (Saccharum spp. L.) mechanical harvesting system leaves a large amount of straw mulch on the soil surface. The straw mulch may affect soil conditions, root regrowth, and sugarcane ...yield. Thus, this study assessed the response of sugarcane root system growth and stalk yield to different rates of straw removal. An experiment was conducted in a Rhodic Kandiudox with sand clay loam texture to test the impact of four rates of straw removal: no removal (18.9 Mg ha−1 of dry mass); moderate removal (8.7 Mg ha−1); high removal (4.2 Mg ha−1) and total removal on sugarcane root system and stalk yield. Higher concentrations of roots (60%) were found in the first 40 cm of soil. Moderate straw removal resulted in higher root mass (3.6 Mg ha−1) and stalk production (23 Mg ha−1 of dry mass). However, no straw removal reduced root mass by <40% (2099 kg ha−1) and reduced stalk yield by >20% (105 Mg ha−1). Through regression analysis, it was estimated that retaining between 8.5 and 13 Mg ha−1 of straw resulted in the highest root mass and stalk yield. Managing straw removal to retain a moderate amount enables producers to sustain suitable soil conditions for sugarcane root growth and stalk production while providing straw for industrial use.
•We compute rates of soil C accumulation under no-tillage management.•We compare both the synchronic and diachronic approach.•More moderate rates of soil C accumulation were observed ...diachronically.•Results suggest that diachronic approach might be more conservative.
No-tillage (NT) practices with crop residue mulching are seen as an effective way to accumulate soil carbon (C). The rate of soil C accumulation can be determined by measuring soil C stocks over time (diachronic approach) or along a chronosequence that substitutes spatial history differences for time differences (synchronic approach). The objective of this communication is to compare the diachronic and synchronic approaches for determining the rates of soil C storage under NT in the Cerrado region of Brazil. In 2003 and 2007, soil C stocks (0–20cm) were determined in three NT fields with 5, 9 and 17 years of NT adoption in 2007 (NT-5, NT-9 and NT-17, respectively), one conventionally tilled field (CT, 30 years of tillage in 2007) and one native Cerrado plot (CE) in Rio Verde (Goiás state, Brazil). Soil C accumulation rates were calculated following both the synchronic and diachronic approach. Results from the synchronic approach showed that 30 years of cropping under CT depleted the soil C stock to 34.4MgCha−1, which is a decrease of about 27% of the original levels observed under the native vegetation (CE, 47.1 and 47.3MgCha−1, respectively, in 2003 and 2007). Instead, NT adoption had been accumulating soil C through the evaluated years. Soil C stocks measured under NT areas in 2003 and 2007 were 29.9 and 31.3MgCha−1 (NT-5), 33.4 and 34.4MgCha−1 (NT-9) and 45.8 and 46.4MgCha−1 (NT-17), respectively. Much more moderate rates of soil C accumulation were observed diachronically (0.12–0.28MgCha−1year−1) than with the synchronic approach (1.33 and 1.27MgCha−1year−1 in 2003 and 2007, respectively). Soil C stocks under CE between 2003 and 2007 (in the diachronic approach) did not change, indicating that diachronic measurements were accurate. Thus, it appears to be very difficult to eliminate all non-wanted sources of soil C variation (i.e. soil texture, land-use history) analysing the soil C accumulation in a chronosequence (synchronic approach). In spite of a time span of years between sampling dates, our results suggest the need for using the diachronic approach when assessing soil C changes under altering land-use or management patterns. Increasing the number of diachronic assessments may also help the parameterization of process-oriented models for exploring the effects of no-tillage systems on soil C storage rates more accurately.
Plastics of petrochemical origin are materials difficult to degrade, and they have caused environmental impacts. The development of new biotechnological strategies for the production of bioplastics ...has attracted the attention of researchers all over the world, enabling the production of economically more viable, biodegradable materials with different possibilities of application in various industrial sectors. The polyhydroxyalkanoates are biopolymers with physicochemical properties similar to those of polypropylene, polystyrene, and polyethylene commonly used by the industry. These bioplastics can be biosynthesized by various microorganisms and accumulate polyhydroxyalkanoates granules intracellularly. The high cost of polyhydroxyalkanoates production is still a limiting factor for its large-scale production, and the costs associated with the carbon source used are one of the reasons that increase the price of the product. This review discusses the main factors associated with polyhydroxyalkanoates production, providing an overview of the different attempts to produce the biopolymer from the use of low-cost substrates and the development of different fermentation strategies for the production of these polymers.
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