Early Regrowth Research Articles

Short-term outcomes from the 'Watch and Wait' (WoW) study: prospective cohort study.

Despite absence of level 1 evidence on the long-term oncological safety of non-operative management for rectal cancer (watch and wait), increased implementation has occurred globally over the past decades. In Sweden, a pan-national prospective non-randomized study was initiated in 2017 to assess its implementation. Patients with biopsy-proven rectal cancer receiving neoadjuvant therapy according to national guidelines in whom a clinical complete response was detected at reassessment were eligible for inclusion following informed consent. Only patients with an opportunistic watch-and-wait approach were included. Inclusion and follow-up, according to the study protocol, was managed at the participating study centres. The primary outcome measure of the study is 3-year disease-free survival. Here, the secondary short-term outcomes local regrowth rate, distant metastasis rate and outcomes after surgery for regrowth, at 6 months follow-up, are reported. Between January 2017 and February 2023, 211 patients with a clinical complete response were included in the study. Thirty-three (16%) patients developed suspicious regrowth within 6 months of inclusion. Thirty-two of 33 patients had abdominal resectional surgery for regrowth. The curative intention rate was 94% for patients with regrowth. Three patients (1.4%) developed distant metastases within 6 months of inclusion. This Swedish national study on watch and wait reports regrowth rates after 6 months are in line with previous reports in the literature. Nearly all patients with early regrowth could be treated with salvage surgery and curative intent.

К вопросу о перспективах возделывания овсяницы тростниковой (Festuca arundinacea Schreb.) на орошаемых землях Нижнего Поволжья

Purpose: to perform a review of an under-investigated bluegrass crop – tall fescue (Festuca arundinacea Schreb.), which is not widespread in forage production, but has some advantages over other bluegrass grasses. Discussion. Tall fescue is characterized by high seed and forage yields, a long-time growing season, early regrowth in spring, an ability to vegetate until late autumn, and an active regrow capacity. Fescue agrocenoses are responsive to irrigation and a high background of mineral nutrition. The ability to grow on saline and alkalini soils is also important. It is widely used for slope and ravines stabilization. Providing optimal combinations of plant life factors creates conditions for good growth, development and formation of high productivity for a long time as well as allows the crop to persist and prevail in multi-species agrocenoses in a wide variety of soil and climatic conditions – from forest and forest-steppe to steppe and semi-desert regions. Tall fescue grows well in damp places under natural conditions. This moisture-loving plant tolerates moisture-saturated, heavy loamy soils well. Regulation of the water regime of fescue crops ensures a more complete use of the biological potential of the crop, which is expressed in the receipt of two additional mowings, compared to natural moisture conditions. Tall fescue is used mainly in the form of hay, silage and haylage. Conclusion. Cultivation of tall fescue against the background of mineral fertilizer application and irrigation ensures an yield increase on average up to 15 t/ha of dry matter and up to 2.5 t/ha of crude protein collection. The wide distribution of this valuable crop in forage production in arid zones is hampered by the lack of scientifically based rational methods for creating highly productive grass stands and elements of cultivation technology.

Cryopreservation of Duckweed Genetic Diversity as Model for Long-Term Preservation of Aquatic Flowering Plants.

Vegetatively propagating aquatic angiosperms, the Lemnaceae family (duckweeds) represents valuable genetic resources for circular bioeconomics and other sustainable applications. Due to extremely fast growth and laborious cultivation of in vitro collections, duckweeds are an urgent subject for cryopreservation. We developed a robust and fast DMSO-free protocol for duckweed cryopreservation by vitrification. A single-use device was designed for sampling of duckweed fronds from donor culture, further spin-drying, and subsequent transferring to cryo-tubes with plant vitrification solution 3 (PVS3). Following cultivation in darkness and applying elevated temperatures during early regrowth stage, a specific pulsed illumination instead of a diurnal regime enabled successful regrowth after the cryopreservation of 21 accessions of Spirodela, Landoltia, Lemna, and Wolffia genera, including interspecific hybrids, auto- and allopolyploids. Genome size measurements revealed no quantitative genomic changes potentially caused by cryopreservation. The expression of CBF/DREB1 genes, considered as key factors in the development of freezing tolerance, was studied prior to cooling but was not linked with duckweed regrowth after rewarming. Despite preserving chlorophyll fluorescence after rewarming, the rewarmed fronds demonstrated nearly zero photosynthetic activity, which did not recover. The novel protocol provides the basis for future routine application of cryostorage to duckweed germplasm collections, saving labor for in vitro cultivation and maintaining characterized reference and mutant samples.

Growth characteristics and post trimming regrowth potential of tropical and sub-tropical landscape hedge plants in response to spacing

Spacing of landscape plants is one of the factors determining the outcome of a design in terms of canopy formation which is one of the variables for aesthetic appearance in terms of shapes and forms. This study was conducted between September 2016 and September 2017, to determine the appropriate intra-row spacing for five plant species in hedge formation. The plant species used were Duranta erecta, Hamelia patens, Ficus retusa, Buxus sempervirens and Acalypha wilkesiana. Transplanting was done at intra-row spacing of 30, 40, 50 and 60cm and a constant inter-row spacing of 100cm. The experiment was a Randomized Complete Block Design in split plot arrangement with three replicates. Plant height, number of leaves, number of branches and canopy space, as indices of species suitability for use as hedge, were measured fortnightly. Plant regrowth and aesthetic characteristics were assessed after periodic trimming. H. patens and B. sempervirens species had the tallest plants. B. sempervirens and D. erecta produced the highest number of leaves while D. erecta and H. patens had the highest number of branches. D. erecta had significantly (p<0.05) the fastest post-trimming shoot regrowth rate relative to other species following the 1st and 2nd trimming (25 and 28 WAT respectively). The effect of spacing on shoot regrowth length was significant after the 3rd, 4th and 5th trimmings (31, 34 and 37 WAT respectively). The highest shoot regrowth height was recorded at 40cm spacing followed by 30cm intra row spacing. All species responded best at 50cm intra-row spacing for the number of branches and canopy space as well as early hedge formation. The study concluded that B. sempervirens was suitable for ideal hedging at 40cm intra-row spacing while A. wilkiesiana and H. patens were only suitable as informal hedges. Hence, B. sempervirens species is recommended as the ideal hedge plant choice based on its early regrowth after trimming, high leaf and branch production as well as overall speed in hedge formation at 31WAT.

Rumen Fermentation Profile and Greenhouse Gas Mitigation of Three Forage Species from Agroforestry Systems in Dry and Rainy Seasons

The variability of climatic conditions throughout the year and the physiological maturity of plant material can have effects on the nutritional value of plants and the productive performance of animals. The aim was to determine the effect of three tropical forage species (Tithonia diversifolia, Erythrina poeppigiana and Cratylia argentea) harvested at four cutting ages (30, 45, 60 and 75 days), during the dry and rainy seasons on in vitro gas production, rumen pH, volatile fatty acids (VFA) and CH4 production. A completely randomized design in a factorial arrangement (three forage species, four cutting ages and two seasons) was used. Four Brahman bulls of 250.0 ± 20.5 kg of live weight were used, provided with a ruminal cannula for the extraction of ruminal fluid. The animals were kept separately in individual pens, where they were fed with P. maximum and water was provided ad libitum. Gas production among forage species was lower (p = 0.0001) in T. diversifolia and E. poeppigiana in the dry season. The cutting age had an influence on gas production, showing lower production (p = 0.0164) at 30 and 45 days in the dry season. The VFA production showed differences for the effect between forages in the rainy season, with higher values (p < 0.05) for acetic, propionic and butyric acid in the species E. poeppigiana, C. argéntea and T. diversifolia respectively. CH4 production showed differences between forage species, showing the lowest (p = 0.0001) production of CH4 in T. diversifolia for the dry and rainy seasons. It is concluded that the use of shrubby species (T. diversifolia, E. poeppigiana and C. argéntea) in ruminant production systems in the rainy and dry seasons, with an early regrowth age (30 and 45 days), present a promising alternative on the reduction of CH4.

Hair safe study: Effects of scalp cooling on hair preservation and hair regrowth in breast cancer patients receiving chemotherapy - A prospective interventional study

Hair safe study: Effects of scalp cooling on hair preservation and hair regrowth in breast cancer patients receiving chemotherapy - A prospective interventional study

Improving the CROPGRO Perennial Forage Model for simulating growth and biomass partitioning of guineagrass

AbstractTropical forage grasses are used for several applications including grazing, silage, and biofuels; with harvesting at varying phenological stages. Mechanistic simulation models can be powerful tools to assist with planning and decision making of pasture utilization strategies. The objective of this study was to improve and evaluate the ability of the Cropping System Model‐CROPGRO‐Perennial Forage model (CSM‐CROPGRO‐PFM) to simulate growth and biomass partitioning of two guineagrass [Panicum maximum Jacq. syn. Megathyrsus maximus (Jacq.) BK Simon & SWL Jacobs] cultivars, Tanzânia and Mombaça. Data from two experiments with contrasting harvest management and field conditions were used. Model parameters were modified, targeting improvement in d‐statistic and root mean square error (RMSE) for aboveground, leaf, stem biomass, leaf area index (LAI), and leaf proportion of aboveground biomass. Major improvement in model performance was achieved by modifying the vegetative partitioning parameters between leaf and stem through increasing partitioning to leaf during early regrowth while increasing it to stem during late regrowth. Modifications were made to parameters affecting leaf and stem senescence, leaf photosynthesis, and leaf area expansion sensitivity to cool weather. The RMSE values decreased from 2,261 to 1,768 kg ha−1 for aboveground biomass, from 1,620 to 874 kg ha−1 for stem biomass, from 11.41 to 7.27% for leaf percentage, from 1.91 to 1.68 for LAI, but increased slightly for leaf biomass. The d‐statistic computed over all these variables increased from .86 to .93. The improved model performance for both short and long harvest cycles will facilitate further applications for diverse forage crops utilization strategies.

ВЛИЯНИЕ БИОЛОГИЧЕСКИХ ПРЕПАРАТОВ НА КОНСЕРВИРОВАНИЕ КОЗЛЯТНИКА ВОСТОЧНОГО (GALEGA ORIENTALIS LAM.)

Galega orientalis Lam. is a valuable forage crop due to its early regrowth, rapid growth, long-term use, high productivity and nutritional value. Given the uniqueness and wide range of applications, the study of the technology of harvesting haylage from this grass is very relevant. The purpose of the work is to conduct a comparative assessment of the process of preserving haylage from Galega orientalis in laboratory model experiments using the bio-preservative Bioamid-3 and plant growth regulator Melafen, as well as their complex application (Bioamid-3 + Melafen). The research was carried out in 2018-2019 in the department of agrobiological research Tatar Scientific Research Institute of Agriculture, Kazan Scientific Center, Russian Academy of Sciences. According to the scheme of an experiment, in samples of green mass Galega orientalis Lam. the studied preparations were introduced: Bioamid-3 – 2.5 g/t, Melafen - 0.1 g/t; were tamped into hermetically sealed vessels with a capacity of 3.0 liters and sent for storage in a darkened room. Opening and further determination of the chemical composition of haylages according to the methods E.A. Petukhova’s was carried out on the 60th day of conservation. As a result of the experiments, it was found that due to the addition the drug Bioamid-3 in haylage, the preservation of crude protein increased by 3.55% (p <0.05), crude fiber - 0.23%, nitrogen-free extract (NFE) - 7.62% (p <0.05), crude fat - 1.41% (p <0.05) and metabolic energy concentration - 13.76% (p <0.05) in relation to the control sample without adding a preservative. Use of the combination Bioamid-3 + Melafen, along with an increase in crude protein by 1.9%, NFE - 3.71%, crude fat 0.74%, metabolic energy 12.59% (p <0.05) made it possible to achieve the optimal value pH at 4.45 and an increase in the accumulation of organic acids by 0.44% (p <0.05) in the finished feed

Effect of maturity and storage duration on plantain (Plantago lanceolata) silage quality

Plantain (Plantago lanceolata) is known as a plant which is able to mitigate N leaching to the soil. Plantain also has high in nutrition and palatable. Unfortunately, nutrition content of plantain if it is conserved as silage is none. To address this question, the effect of regrowth stage and storage duration on ensiling properties of plantain were compared using replicated mini-silos (500 g FW). A factorial completely randomized design with three levels of regrowth stage (4-leaf, 5-leaf and 6-leaf appearance) and 4 levels of storage durations (80, 120, 150, 180 days) and five silo replicates was used. In this study 6-leaf had more fibre and less sugars. Ensiling properties was affected by pre and post-harvest management (P<0.001). Late harvest (6L) had higher pH and lactic acid than early harvest (4L or 5L). The nutritive value of plantain silage was better at early harvest than that of at late harvest (P<0.05). It can be concluded that ensiling plantain at earlier regrowth stage of improved the quality of plantain silage. This study suggests that silage made from the early regrowth stage can be stored until 120 days to produce good quality of silage.

Imaging and Management of Rectal Cancer

High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a "watch and wait" approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.

Satellite Image-Based Time Series Observations of Vegetation Response to Hurricane Irma in the Lower Florida Keys

High-resolution satellite imaging represents a potentially effective technique to monitor cyclone-caused environmental damage and recovery over large areas at a high spatial scale. This study utilized a 10-m resolution Sentinel satellite image series to document vegetation changes in a portion of the Florida Keys, USA, over which the core of Category 4 Hurricane Irma passed on 10 September 2017. A previously assembled field survey was used to establish land-cover patterns in the satellite data, and concurrent field measurements verified post-hurricane changes. Normalized difference vegetation index (NDVI) was utilized as a tracer for pre-storm baseline patterns and through 19 post-storm months. NDVI patterns show that the severity of vegetation damage varied appreciably across the area, with the least damage on islands in the western sector of the hurricane’s eye and around its center, and greatest damage on islands just east of the eye. The data reveal that for 2.5 months after the storm, multiple inland vegetation classes showed substantial early regrowth. However, mangrove forests were more negatively affected. The storm caused extensive mortality of black mangrove (Avicennia germinans) and red mangrove (Rhizophora mangle), corresponding to more than 40% of the total mangrove area on some islands. The full extent of mangrove die-off was not immediately evident, and increased progressively through the first few months after the storm. In addition to demonstrating the utility of high-resolution satellite image series for post-hurricane environmental assessment, this study reveals high-resolution links between vegetation types, their location within the cyclone, and the extent of post-storm recovery.

Effect of dietary omega-3 fatty acids on castrate-resistant prostate cancer and tumor-associated macrophages.

BackgroundM2-like macrophages are associated with the pathogenesis of castrate resistant prostate cancer (CRPC). We sought to determine if dietary omega-3 fatty acids (ω−3 FAs) delay the development and progression of CRPC and inhibit tumor associated M2-like macrophages.MethodsMycCap cells were grown subcutaneously in immunocompetent FVB mice. Mice were castrated when tumors reached 300mm3. To study effects of dietary ω−3 FAs on development of CRPC, ω−3 or ω−6 diets were started two days after castration and mice sacrificed after early regrowth of tumors. To study ω−3 FA effects on progression of CRPC, tumors were allowed to regrow after castration before starting the diets. M2 (CD206+) macrophages were isolated from allografts to examine ω−3 FA effects on macrophage function. Omega-3 fatty acid effects on androgen-deprived RAW264.7 M2 macrophages was studied by RTqPCR and a migration/ invasion assay.ResultsThe ω−3 diet combined with castration lead to greater MycCap tumor regression (182.2±33.6 mm3) than the ω−6 diet (148.3±35.2; p=0.003) and significantly delayed the time to CRPC (p=0.006). Likewise, the ω−3 diet significantly delayed progression of established castrate resistant MycCaP tumors (p=0.003). The ω−3 diet (as compared to the ω−6 diet) significantly reduced tumor associated M2-like macrophage expression of CSF-1R in the CRPC development model, and matrix metallopeptidase-9 (MMP-9) and vascular endothelial growth factor (VEGF) in the CRPC progression model. Migration of androgen depleted RAW264.7 M2 macrophages towards MycCaP cells was reversed by addition of docosahexaenoic acid (ω−3).ConclusionsDietary omega-3 FAs (as compared to omega-6 FAs) decreased the development and progression of CRPC in an immunocompetent mouse model, and had inhibitory effects on M2-like macrophage function. Clinical trials are warranted evaluating if a fish oil-based diet can delay the time to castration resistance in men on androgen deprivation therapy, whereas further pre-clinical studies are warranted evaluating fish oil for more advanced CRPC.

Land-use impacts on the composition and diversity of the Baikiaea– Guibourtia–Pterocarpus woodlands of north-western Zimbabwe

Variation in floristic composition of recovering Baikiaea–Guibourtia–Pterocarpus woodlands was studied in different development stages (from early regrowth to mature woodland) under different land-use systems (protected areas, timber harvesting, pole and firewood collection, and abandoned crop fields), in the Gwayi and Tsholotsho areas in north-western Zimbabwe. A total of 150 nested circular plots were sampled representatively in four different development stages related to the land-use systems. The DBH (stem diameter at 1.3 m above ground level) and tree height were recorded by species for all stems of tree species with DBH ≥ 15 cm in a 30-m-radius plot (0.283 ha) and for trees with DBH 5.0–14.9 cm in a 11.3-m-radius plot (0.04 ha) (both centred around the same midpoint). Stems with DBH < 5 cm were counted by species in an inner sub-plot of 5.65 m (0.01 ha) radius. Tree data (stem DBH ≥ 5 cm) and regeneration data (stem DBH < 5 cm) by stem counts per species per plot, were used separately to run TWINSPAN (TWo-way INdicator SPecies ANalysis) classifications of species assemblages. Importance values were calculated for all tree species per community. Shannon–Wiener diversity indices were calculated for each community and tested for differences using one-way ANOVA in SPSS version 21. Detrended correspondence analysis (DCA) implemented in the CANOCO ordination software was used to determine the extent of variation amongst the identified communities. The classification identified 12 tree communities and 13 regeneration communities, clustering plots from different land uses together. Baikiaea plurijuga was the most important tree species in all tree communities, except where Combretum collinum, C. apiculatum, Commiphora mossambicensis and Pterocarpus angolensis were dominant. Pterocarpus angolensis showed low importance in most communities, except for communities from undisturbed sites (mostly mature trees) and abandoned fields (mostly young trees). Baikiaea plurijuga was most important in most regeneration communities, except in communities dominated by Baphia massaiensis, C. collinum, C. apiculatum and P. angolensis. Species diversity differed significantly (p < 0.05) amongst tree communities. The DCA ordination showed little variation amongst the communities. The cumulative contribution of environmental factors explaining variation in species composition was 22.6% for tree communities and 26.1% for regeneration communities, suggesting that recovery from disturbance after different land uses may explain more of such variation.

Impact on survival of early tumor growth between surgery and radiotherapy in patients with de novo glioblastoma.

Systematic pre-radiotherapy MRI in patients with newly resected glioblastoma (OMS 2016) sometimes reveals tumor growth in the period between surgery and radiotherapy. We evaluated the relation between early tumor growth and overall survival (OS) with the aim of finding predictors of regrowth. Seventy-five patients from 25 to 84years old (Median age 62years) with preoperative, immediate postoperative, and preradiotherapy MRI were included. Volumetric measurements were made on each of the three MRI scans and clinical and molecular parameters were collected for each case. Fifty-four patients (72%) had an early regrowth with a median contrast enhancement volume of 3.61cm3-range 0.12-71.93cm3. The median OS was 24months in patients with no early tumor growth and 17.1months in those with early tumor regrowth (p = 0.0024). In the population with initial complete resection (27 patients), the median OS was 25.3months (19 patients) in those with no early tumor growth between surgery and radiotherapy compared to 16.3 months (8 patients) in those with tumor regrowth. In multivariate analysis, the initial extent of resection (p < 0.001) and the delay between postoperative MRI and preradiotherapy MRI (p < 0.001) were significant independent prognostic factors of regrowth and of poorer outcome. We demonstrated that, in addition to the well known issue of incomplete resection, longer delays between surgery and adjuvant treatment is an independent factors of tumor regrowth and a risk factor of poorer outcomes for the patients. To overcome the delay factor, we suggest shortening the usual time between surgery and radiotherapy.

Key factors that influence for seasonal production of Guinea grass

Climate, soil and management are the main drives for growth and production of tropical pastures. Thus, a better understanding of the effects of these factors and their interactions under climate conditions is required to obtain effective management options. Here, we used data from two field trials to research on climate and management interactions on the production seasonality of Panicum maximum Jacq. Treatments included four sampling times (250, 500, 750, and 1000 °C accumulated) during eight regrowth period, under irrigated and rainfed conditions and, cuts were made to simulate grazing intensity. All treatments were arranged in a completely randomized block design with four replications. At each sampling time, basal tillers were sampled to observe meristematic differentiation and were linked with the respective daylength. Soil moisture was determined, and the water availability index (WAI) was calculated. The dry matter production (DMP) was taken and relative productivity was calculated. Soil moisture was the key seasonal drive in spring-summer and the WAI could be used to adjust the maximum production for that season. The major drive for DMP in fall was the daylength, which was found at 11.81 h. For all seasons, DMP correlated better with the residues in early regrowth phase (r = 0.82 and p < 0.0001) and with degree-days at final regrowth phase (r = 0.73 p < 0.01). Applying these critical values to management guidelines should make Guinea grass DMP more efficient on tropical farms.

Intraoperative radiotherapy during kyphoplasty for vertebral metastases (Kypho-IORT): first clinical results.

Kyphoplasty is an effective procedure providing structural stability and pain alleviation in vertebral metastases. To prevent early regrowth, patients typically receive postoperative fractionated radiotherapy, which is associated with long treatment duration. Therefore, we established a new approach to deliver intraoperative radiotherapy during kyphoplasty to shorten the treatment time and reach structural stability and sterilization of the metastases (Kypho-IORT). For Kypho-IORT, a 50 kV X-ray source with a specially designed applicator was used. A radiation dose of 8 Gy in 5 mm distance was delivered. After radiation the device was removed and the kyphoplasty was completed according to the standard procedure. Since August 2009, 18 patients with instable or painful spinal metastases received Kypho-IORT. The median age was 63 years (range, 43-73). Kypho-IORT was successfully performed in 18 of 21 vertebral lesions (86%). No severe complications occurred during or early after IORT. The median pain score using a visual analogue scale decreased from 5/10 before the procedure to 2.5/10 at day 1 (P <0.001) and to 0/10 six weeks after the procedure (P = 0.001). Imaging studies were available for 15 of 18 patients. Stable disease within the irradiated vertebral body was seen in 14 patients (93%) and local progressive disease in one patient (7%). No re-irradiation due to local progressive disease or pain recurrence was necessary within the median follow-up of 4.5 months. Kypho-IORT is well tolerated without severe side effects and provides fast improvement of pain. Although stable disease was seen in 93% of the patients, a longer follow-up is necessary to assess the effectiveness. A dose escalation study to establish the maximally tolerated dose has been initiated.

Short term patterns of germination in response to litter clearing and exclosure of large terrestrial vertebrates along an Amazon forest regrowth gradient

Efforts to restore tropical forest ecosystem services depend on understanding the barriers to germination of species of economic and cultural interest. Here we use two important non-timber forest product species (NTFP: Inga capitata. Desv. – Fabaceae and Euterpe oleracea Mart. – Arecaeae) to compare germination across a forest regrowth gradient in the northeast Brazilian Amazon. Experimental treatments were used to examine the effects of mid to large-bodied vertebrates and litter cover on seed fate (germination, removal and invertebrate infestation) in 15 lowland sites within small-holder properties. Regrowth stage was classified into three groups, with five sites each of: late second-regrowth forest, early second-regrowth forest and abandoned pasture. We conducted a paired split-plot experiment using experimental plots composed of a vertebrate exclosure versus an open treatment and subplots with and without litter. We used Generalized Linear Mixed-Effects Models (GLMMs) to compare additive and interaction effects of treatments across regrowth stages compared with 15 paired control sites. We found that the effects of regrowth stage and exclosure were species specific and these effects differed between responses (germination, removal and invertebrate infestation). Clearing litter generated a significant effect only for invertebrate infestation, which increased in the cleared plots. Our findings show that seed removal limits germination success for both species across forest regrowth stages, with invertebrate infestation also having important but secondary effects. Increased removal and unfavorable abiotic conditions make direct seeding unviable in pasture sites. We suggest that direct seeding is a viable alternative for the establishment of these widely available NTFP species in late and early regrowth forests.

Humic Acid and Synthesized Humic Mimic Promote the Growth of Italian Ryegrass

Humic acid (HA) is a complex organic matter found in the environments, especially in grassland soils with a high density. The bioactivity of HA to promote plant growth depends largely on its extraction sources. The quality-control of HA and the quality improvements via an artificial synthesis are thus challenging. We recently reported that a polymeric product from fungal laccase-mediated oxidation of catechol and vanillic acid (CAVA) displays a HA-like activity to enhance seed germination and salt stress tolerance in a model plant, Arabidopsis. Here, we examined whether HA or CAVA enhances the growth of Italian ryegrass seedling. Height and fresh weight of the plant with foliar application of HA or CAVA were bigger than those with only water. Interestingly, enhanced root developments were also observed in spite of the foliar treatments of HA or CAVA. Finally, we proved that HA or CAVA promotes the regrowth of Italian ryegrass after cutting. Collectively, CAVA acts as a HA mimic in Italian ryegrass cultivation, and both as a biostimulant enhanced the early growth and regrowth after cutting of Italian ryegrass, which could improve the productivity of forage crops.

Coordinated nitrogen and carbon remobilization for nitrate assimilation in leaf, sheath and root and associated cytokinin signals during early regrowth of Lolium perenne.

The efficiency of N assimilation in response to defoliation is a critical component of plant regrowth and forage production. The aim of this research was to test the effect of the internal C/N balance on NO3- assimilation and to estimate the associated cytokinin signals following defoliation of perennial ryegrass ( Lolium perenne L. 'Grasslands Nui') plants. Plants, manipulated to have contrasting internal N content and contrasting availability of water soluble carbohydrates (WSCs), were obtained by exposure to either continuous light or short days (8:16 h light-dark), and watered with modified N-free Hoagland medium containing either high (5m m ) or low (50 μ m ) NO3- as sole N source. Half of the plants were defoliated and the root, sheath and leaf tissue were harvested at 8, 24 and 168 h after cutting. The spatiotemporal changes in WSCs, synthesis of amino acids and associated cytokinin content were recorded after cutting. Leaf regrowth following defoliation involved changes in the low- and high-molecular weight WSCs. The extent of the changes and the partitioning of the WSC following defoliation were dependant on the initial WSC levels and the C and N availability. Cytokinin levels varied in the sheath and root as early as 8 h following defoliation and preceded an overall increase in amino acids at 24 h. Subsequently, negative feedback brought the amino acid response back towards pre-defoliation levels within 168 h after cutting, a response that was under control of the C/N ratio. WSC remobilization in the leaf is coordinated with N availability to the root, potentially via a systemic cytokinin signal, leading to efficient N assimilation in the leaf and the sheath tissues and to early leaf regrowth following defoliation.

Depletion of carbohydrate reserves limits nitrate uptake during early regrowth in Lolium perenne L.

The mechanisms linking C/N balance to N uptake and assimilation are central to plant responses to changing soil nutrient levels. Defoliation and subsequent regrowth of grasses both impact C partitioning, thereby creating a significant point of interaction with soil N availability. Using defoliation as an experimental treatment, we investigated the dynamic relationships between plant carbohydrate status and NO3--responsive uptake systems, transporter gene expression, and nitrate assimilation in Lolium perenne L. High- and low-affinity NO3- uptake was reduced in an N-dependent manner in response to a rapid and large shift in carbohydrate remobilization triggered by defoliation. This reduction in NO3- uptake was rescued by an exogenous glucose supplement, confirming the carbohydrate dependence of NO3- uptake. The regulation of NO3- uptake in response to the perturbation of the plant C/N ratio was associated with changes in expression of putative high- and low-affinity NO3- transporters. Furthermore, NO3- assimilation appears to be regulated by the C-N status of the plant, implying a mechanism that signals the availability of C metabolites for NO3- uptake and assimilation at the whole-plant level. We also show that cytokinins may be involved in the regulation of N acquisition and assimilation in response to the changing plant C/N ratio.