Successful Plant Establishment Research Articles

Co-option of plant gene regulatory network in nutrient responses during terrestrialization.

Plant responses to nitrate, phosphate and sucrose form a complex molecular network crucial for terrestrial adaptation. However, the origins, functional diversity and evolvability of this network during plant terrestrialization remain scarcely understood. Here we compare the transcriptomic response to these nutrients in the bryophyte Marchantia polymorpha and the streptophyte alga Klebsormidium nitens. We show that the largely species-specific nutrient response pattern is driven by gene regulatory network (GRN) alterations. Intriguingly, while pathways governing the GRNs exhibit modest conservation, M. polymorpha GRNs exhibit more regulatory connections through the redeployment of ancient transcription factor CSD. In M. polymorpha, functional analyses reveal the involvement of pre-existing cytokinin machineries in downstream targets, orchestrating plastic morpho-physiological responses to nutrient status. Our findings implicate the genetic co-option events facilitating successful land plant establishment.

Active restoration efforts drive community succession and assembly in a desert during the past 53 years.

Regreening efforts in deserts have been implemented globally to combat land degradation and desert expansion, but how they affect above- and belowground community succession and assembly processes remains unknown. Here, we examined variations in plant and soil microbial community attributes along a 53-year restoration chronosequence following the establishment of straw checkerboard barriers (SCBs) in the Tengger Desert of China. This approach is a combination of fixing shifting sand and adding organic material (straw) simultaneously to expedite vegetation restoration by enhancing the success of plant establishment. Our findings revealed that the establishment of SCBs significantly triggered plant and soil microbial communities to gradually approximate those of the natural community along restoration duration. We observed positive and negative bidirectional shifts in plant and soil microbial community composition. Critical temporal threshold zones for relatively rapid changes in community composition were identified, with 2-15.5 years for plants, 0.5-8.5 years for bacteria, and 2-8.5 years for fungi. This suggests a delayed response of plant communities to restoration efforts compared with soil microbial communities. Both stochastic and deterministic processes regulated plant and soil microbial community assembly. Stochastic processes played a more important role in plant and fungal community succession, whereas deterministic processes primarily governed bacterial succession. In terms of deterministic processes, temporal variations in community composition mainly resulted from the intrinsic correlations among plant, bacterial, and fungal communities, as well as an increase in soil organic carbon (SOC) with restoration duration. Thus, temporal patterns and functional contributions of bacterial communities appear to be more predictable than those of plant and fungal communities during desert ecosystem restoration. This study emphasizes that plant-bacteria-fungi correlations and increasing SOC content are critical for accelerating community succession and promoting dryland restoration. Future studies should explore and integrate temporal variations and restoration effects of multiple ecosystem functions to better predict dryland development and resilience to global climate changes over a large temporal scale.

Inventorization and Exploration of Floral Diversity in Metropolitan Cities of India for Their Suitability in Floriculture of Kashmir

Floriculture is the branch of horticulture that deals with the cultivation and management of flowers and ornamental plants and has blossomed into commercial activity with considerable growth and a useful crop diversification option, particularly for small farmers over the past three decades. It is a global industry with significant economic, social, and aesthetic values. Globally 171 countries practice floriculture. India occupies 51st position in terms of exports and contributes Rs. 455 crores which is 0.06% of global trade. The present study was carried out during the College on Wheels project organized by the Higher Education Council, Union Territory of Jammu & Kashmir, and was aimed to explore the floral and ornamental plant diversity of major metropolitan cities like Delhi, Goa, Bengaluru, Mumbai, etc. of India for evaluating their suitability for introduction in floriculture of Union Territory of Jammu & Kashmir. The floral and ornamental plant species were explored, photographed, evaluated, identified, and inventorised. A total of 51 species belonging to 23 different families of floral and ornamental plants were explored and evaluated in terms of parameters like climate, soil type, photoperiod requirements, watering needs, and maintenance requirements for their cultivation. It was found that some of the explored species of ornamental plants were already introduced into the Union Territory of Jammu and Kashmir because the parameters for the successful growth and thriving of these species match with the existing climatic and other conditions in the Union Territory of Jammu and Kashmir. Besides, the climatic and other requirements of some of the explored species were found in conformity with the climatic and other parameters available in the Union Territory of J&K for the successful establishment and growth of plants. Thus, there is an urgent need to introduce these explored species into the region to enhance the floral diversity of ornamental plants, beautify the landscape, and promote tourism and the generation of better livelihood. The Department of Floriculture should take a lead role in this direction to import these floral and ornamental plant specimens from pan India.

Anthoxanthum odoratum (Poaceae) as a bioindicator of arbuscular mycorrhizal fungi abundance prior to native revegetation on agricultural soils

ABSTRACT Mycorrhizal fungi, which form symbiotic associations with plant roots, can be critical to the successful establishment of plants. Up to 90% of land plant species form associations with arbuscular mycorrhizal fungi (AMF), which develop fungal structures inside host roots. Common site preparation practices prior to ecological restoration, such as soil disturbance and herbicide application, may lessen the availability of AMF, potentially jeopardising plant establishment. However, the state of the soil microbiome can be difficult to assess directly. This study examines the potential of the widespread pasture grass Anthoxanthum odoratum (Sweet Vernal, Poaceae) as a bioassay of AMF abundance in soils. We present a rapid clearing and staining protocol for visualising AMF structures in the roots of A. odoratum. We then compare % colonisation on roots of naturally established A. odoratum plants collected from undisturbed pastures vs. sprayed and tilled pastures. Roots of A. odoratum collected from sprayed and tilled pastures showed a significantly lower average AMF colonisation at 43.8% compared with 57.6% on roots from undisturbed pastures. However, all plants sourced from the sprayed and tilled pastures still showed some AMF structures. Our results strongly suggest that A. odoratum can be a useful bioindicator of AMF presence and abundance in soils, offering a promising tool for seed-based restoration on retired agricultural land.

Habitat-specific allocations of elements in Atriplex lentiformis seeds indicate adaptation to metal toxicity.

Self-sustaining vegetation in metal-contaminated areas is essential for rebuilding ecological resilience and community stability in degraded lands. Metal-tolerant plants originating from contaminated post-mining areas may hold the key to successful plant establishment and growth. Yet, little is known about the impact of metal toxicity on reproductive strategies, metal accumulation, and allocation patterns at the seed stage. Our research focused on the metal tolerant Atriplex lentiformis. Specifically, we examined the effects of toxic metal(loid) concentration in soils on variability in its reproductive strategies, including germination patterns, elemental uptake, and allocation within the seeds. We employed advanced imaging techniques like synchrotron X-ray fluorescence microscopy (2D scans and 3D tomograms) combined with inductively coupled plasma mass spectrometry to reveal significant differences in metal(loid) concentration and distribution within the seed structures of A. lentiformis from contrasting habitats. Exclusive Zn hotspots of high concentrations were found in the seeds of the metallicolous accession, primarily in the sensitive tissues of shoot apical meristems and root zones of the seed embryos. Our findings offer novel insights into phenotypic variability and metal tolerance and accumulation in plants from extreme environments. This knowledge can be applied to enhance plant survival and performance in land restoration efforts.

Forest topsoil salvage and placement depth affects oil sands reclamation in the boreal forest.

Reclamation of disturbances from oil sands mining requires effective soil management to ensure successful plant establishment and to promote recovery of native plant communities. In this study we investigated the effects of salvage depths (shallow vs. deep) and placement depths (shallow vs. deep) of forest topsoil on plant establishment, species richness, and soil properties in two substrate types (sand and peat-mineral). Shallow salvage led to greater tree stem densities and higher canopy cover for most plant groups, although there was no significant difference in species richness between shallow and deep salvages. Deep placement generally resulted in greater canopy cover, while its effect on plant density was very small for most plant groups. On peat-mineral substrate, fewer differences were detected between shallow and deep salvage, and multiple treatments resulted in greater cover. Findings suggest that a balance between maximizing the area over which propagules are redistributed and providing sufficient resources for successful plant establishment is necessary. Forest topsoil from shallow salvages and deep placements is recommended when targeting increased site productivity and species diversity. In contrast, deep salvage should be used when the primary objective is to obtain maximum reclamation material volume. Salvage depth effects may be influenced by substrate type, with peat-mineral substrate providing more favourable conditions for plant establishment. Further research is needed to assess the long-term impacts of different salvage and placement depths on plant community development and the potential effects of substrate properties on soil and plant response.

Effects of growing media, and cultivar on developments and quality of mango rootstock.

In a successful mango plant establishment, the choice of a strong and healthy rootstock is crucial for subsequent propagation. An experiment was conducted during the 2023 mango seedling growing season at the Sokoine University of Agriculture horticultural sections in Morogoro, Tanzania. The study aimed to evaluate the influence of different growing media and cultivars on the growth and development of quality-certified mango rootstock plants. Ripe local mango fruits were collected from neighbouring farms and sown in polyethylene bags containing a mixture of forest soil, sand, farmyard manure, and sawdust. The experiment followed a randomized complete block design with three replications. Data collected included days to 50% germination, seedling mortality, seedling height, stem girth, and chlorophyll content (measured using the SPAD Unit). Results indicated that using sindano cultivars as rootstock significantly reduced days to germination and increased germination percentage (89.5%) while minimizing seedling mortality (2). Additionally, forest soil contributed to maximum seedling height (43.95 cm), stem diameter (0.52 cm), and chlorophyll content (40.05). The interaction between cultivar and growing media significantly influenced various mango seedling growth parameters. Bongwa cultivars planted in growing media composed of forest soil alone or combined with farmyard manure and sand produced high-quality, certifiable mango rootstock plants.

Effect of chemical or organic fertilizers in mining remnant substrate on forage production and marandu grass morphogenesis

Mining drives economic development, but it frequently alters the fertility of remaining soil or substrates. Increasing organic matter in these substrates has been a critical factor for the successful recovery and establishment of plants. In this study, the development of ‘Marandu’ Urochloa brizantha in a Cambisol substrate, a remnant of bauxite mining, was assessed in the municipality of Poços de Caldas-MG, in response to chemical and organic fertilizers derived from vermicomposting of residues from the production of shimeji mushrooms. An experiment was conducted in a greenhouse, where six treatments, namely: conventional fertilizers (FertConv; FertConv + micro and Cal) and exclusively with the use of vermicompost (20, 40 and 60 t ha-1) were evaluated in a completely randomized design in four replications. Fertilization with vermicompost resulted in significant increases in nutrients. Stem and leaf elongation rates, leaf appearance rate, phyllochron, tiller density and dry matter were influenced by both organic and conventional fertilization. However, the greatest benefits were observed with the application of vermicompost. After 90 days of growth, using conventional fertilization, there were no significant increases in the mentioned variables. The use of vermicompost is effective in improving the fertility conditions of the post-mining substrate, with significant impacts on the development of ‘Marandu’ grass, a fact that can contribute to the recovery of areas impacted by mining. Chemical fertilization based only on chemical fertilizers did not result in increases in TAlC, TAlF, TApF, DPP and DM until 90 days of initial growth of ‘Marandu’ grass.

Seed Imbibition and Metabolism Contribute Differentially to Initial Assembly of the Soybean Holobiont.

Seed germination critically determines successful plant establishment and agricultural productivity. In the plant holobiont's life cycle, seeds are hubs for microbial communities' assembly, but what exactly shapes the holobiont during germination remains unknown. Here, 16S rRNA gene amplicon sequencing characterized the bacterial communities in embryonic compartments (cotyledons and axes) and on seed coats pre- and post-germination of four soybean (Glycine max) cultivars, in the presence or absence of exogenous abscisic acid (ABA), which prevented germination and associated metabolism of seeds that had imbibed. Embryonic compartments were metabolically profiled during germination to design minimal media mimicking the seed endosphere for bacterial growth assays. The distinction between embryonic and seed coat bacterial microbiomes of dry seeds weakened during germination, resulting in the plumule, radicle, cotyledon, and seed coat all hosting the same most abundant and structurally influential genera in germinated seeds of every cultivar. Treatment with ABA prevented the increase of bacterial microbiomes' richness, but not taxonomic homogenization across seed compartments. Growth assays on minimal media containing the most abundant metabolites that accumulated in germinated seeds revealed that seed reserve mobilization promoted enrichment of copiotrophic bacteria. Our data show that seed imbibition enabled distribution of seed-coat-derived epiphytes into embryos irrespective of germination, while germinative metabolism promoted proliferation of copiotrophic taxa, which predominated in germinated seeds.

Effect of Seed Hardening on Seed Germination and Morphological Parameters in Linseed (Linum usitatissimum L)

Seed hardening refers to different processes that involve treating seeds to enhance their resilience, break seed dormancy and improve their chances of successful germination and plant establishment during harsh conditions. Seeds are soaked in the solutions of KCl, NAA, KNo3 and CaCl2 to break dormancy increase the germination percentage and improve plant morphological parameters in linseed. The experiment was carried out for “Effect of seed hardening on seed germination and morphological parameters in Linseed (Linum usitatissimum L),, during Rabi season in the year 2022 at Field Experimentation Centre, Department of Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology And Sciences, Prayagraj, Uttar Pradesh on linseed crop. The experiment was laid out in Randomized Complete Block Design (RCBD) with 13 treatments and 3 replications. T0-Control, T1-NAA-25 ppm, T2-NAA-50 ppm, T3-NAA-150 ppm, T4-KCl-25 ppm, T5-KCl-50 ppm, T6-KCl-150 ppm, T7-KNo3-25 ppm, T8-KNo3-50 ppm, T9-KNo3-150 ppm, T10-CaCl2-25 ppm, T11-CaCl2-50 ppm, T12-CaCl2-150 ppm were the treatments. Linseed seeds were treated with NAA, KCl, KNo3 and CaCl2 with different concentrations (25 ppm,50 ppm and 150 ppm) for 5 hours and after sowing growth, yield and yield parameters were observed. The main objectives are to determine the effect of seed hardening on seed germination and morphological characteristics of Linseed and to find out the suitable concentration for seed hardening in Linseed. It was noticed that T9-KNo3-150 ppm treatment performed better significantly different at a 5% level of significance, when compared with other treatments where a minimum was observed in control. The highest germination percentage (92.20%), plant height (74.34 cm), number of primary branches (3.87), number of secondary branches (23.53), seeds per capsule (8.13), seed yield per plant (3.42) and harvest index (25.38%) showing better results when treated with treatment (T9)-KNo3-150 ppm for 5 hours and followed by Treatment(T11) CaCl2-50 ppm. Very less days (72) required for 50% flowering and maturity (111.67) were observed in treatment T9 when compared with other treatments. It concluded that T9(KNo3-150 ppm) was superior in all the growth and yield parameters in linseed. So we recommended that treatment T9 is the best seed hardening treatment for linseed according to this experiment.

Floral resources encourage colonisation and use of green roofs by invertebrates

Green roof retrofits offer a promising avenue to increase greenspace and thus biodiversity in the city. The successful colonisation and establishment of plants and animals on green roofs is limited by the location and context of the green roof. Here we use a before, after, control, impact (BACI) design to monitor the colonisation of a new retrofit roof in Melbourne CBD. We find that colonisation for some taxa occurs rapidly, with honeybees (Apis mellifera) arriving four days after flowers had been planted. Other insect taxa, such as native bees, did not colonise the impact roof but were present on the green roof reference site, which was lower in height and planted with native plants. Invertebrate abundance increased for all sites after the retrofit was built, however this sampling period was in late spring when more insects are expected to be active. Bird richness and abundance didn’t change in response to roof greening, but invertebrate richness was significantly higher on reference sites and increased after the green roof retrofit was built for the impact site. There was an apparent ‘spill over’ effect onto the nearby green roof control, which also increased in invertebrate diversity. Overall, invertebrate composition across roof types was driven by floral density. Floral density and richness increased on the impact roof as vegetation matured, subsequently correlating with higher abundance and richness of invertebrates. We use these findings to discuss colonisation of green roofs and argue for strategic placement of new green roof retrofits to maximise their biodiversity potential.

Seed-Specific Mass and Root Growth Relate to Perennial Bunchgrass Seedling Survivorship Under Highly Limited Nutrient Supply

Maternal provisioning to seeds is critical to later plant success, and identifying seed traits that predict successful plant establishment and resilience may facilitate improved plant material selection for rangeland restoration. Although size-standardized measurements are typically recorded for leaf traits, this is not the case for seed traits. In this study, we investigated whether an area-standardized metric, seed-specific mass (SSM), was better associated with seedling performance relative to simple seed mass. We germinated seeds of bluebunch wheatgrass (Pseudoroegneria spicata [Pursh.] A. Löve), crested wheatgrass (Agropyron cristatum L. var. Hycrest II), and Sandberg bluegrass (Poa secunda Presl.) on sterile agar and tracked seed mass, SSM, and subsequent seedling growth and mortality to investigate relationships between seed traits and seedling performance. SSM showed clear variation among species despite similarities in seed mass, and species-specific patterns of mortality most closely tracked variation in SSM. Crested wheatgrass seedlings that survived to 52 wk had significantly greater SSM than those that perished during the study, and surviving seedlings also had significantly longer roots at wk 4 than those that died. Seed mass and SSM each explained variation in seedling traits to some extent. Simple seed mass best predicted variation in early leaf area within species, while root length was best predicted by SSM across species. Our study is indicative that SSM warrants consideration in future studies investigating maternal energetic provisioning and seedling performance.

Effect of liming and fertilizers on the growth and nutrition of 12-month old Teak (Tectona grandis L.) grown on acidic soil of Peru

Peru has a great potential for forestry plantations, nevertheless, importations of this type of products are getting very expensive. Soils under forest are acidic and infertile to support sustainable economically valuable forest tree species such as teak. Information is lacking on proper fertility management in forest plantations such as teak. Therefore, the objective of this study was to explore the effect of lime, and organic and inorganic fertilizers on the early growth and nutrient composition of 12-month old teak grown on acidic soil of Peru. The soil under field study was acidic with a pH of 4.99, low in fertility. A factorial design of 2x3: Lime (No Lime and Liming) and fertilizer (organic, inorganic and mixture), with 9 repetitions was adopted. Tree biometric parameters (height, diameter, biomass) and N, P, K, Ca, Mg, Fe, Cu, Mn, Zn foliar concentrations were determined during early the growth of teak. Treatments with addition of dolomite lime favored higher biometric parameters, and use of organic fertilizers promoted more growth than inorganic fertilizers. In the case of nutrients, no major differences were observed between limed and unlimed treatments while organic fertilizer promoted Ca, K and S nutrition. The results show that the application of lime and organic fertilizers is essential for the successful management and establishment of teak plants in acidic soils of Peru.

Festuca coelestis Increases Drought Tolerance and Nitrogen Use via Nutrient Supply-Demand Relationship on the Qinghai-Tibet Plateau.

Drought and nutrient deficiency pose great challenges to the successful establishment of native plants on the Qinghai-Tibet Plateau. The dominant factors and strategies that affect the adaptation of alpine herbs to dry and nutrient-deficient environments remain unclear. Three water gradients were established using two-factor controlled experiments: low water (WL), medium water (WM), and high water (WH). The field water-holding capacities were 35%, 55%, and 75%, respectively. Nitrogen fertilizer (N) was applied at four levels: control (CK), low (FL), medium (FM), and high (FH) at 0, 110, 330, and 540 mg/kg, respectively. The results revealed that N was the main limiting factor, rather than phosphorous (P), in Festuca coelestis under drought stress. Under water shortage conditions, F. coelestis accumulated more proline and non-structural carbohydrates, especially in the aboveground parts of the leaves and stems; however, the root diameter and aboveground nitrogen use efficiency were reduced. Appropriate N addition could mitigate the adverse effects by increasing the release of N, P, and enzyme activity in the bulk soil and rhizosphere to balance their ratio, and was mainly transferred to the aboveground parts, which optimized the supply uptake relationship. The effects of water and fertilizer on the physiological adaptability and nutrient utilization of F. coelestis were verified using structural equation modeling. Based on their different sensitivities to water and nitrogen, the WHFM treatment was more suitable for F. coelestis establishment. Our results demonstrated that the disproportionate nutrient supply ability and preferential supply aboveground compared to below ground were the main factors influencing F. coelestis seedling establishment under drought conditions. This study provides evidence for a better understanding of herbaceous plants living in high mountain regions and offers important information for reducing the risk of ecological restoration failure in similar alpine regions.

Legacy Effects of Phytoremediation on Plant-Associated Prokaryotic Communities in Remediated Subarctic Soil Historically Contaminated with Petroleum Hydrocarbons.

Phytoremediation of petroleum hydrocarbons in subarctic regions relies on the successful establishment of plants that stimulate petroleum-degrading microorganisms, which can be challenging due to the extreme climate, limited nutrients, and difficulties in maintaining sites in remote locations. A long-term phytoremediation experiment was initiated in Alaska in 1995 with the introduction of grasses and/or fertilizer to petroleum hydrocarbon (PHC)-contaminated soils that were subsequently left unmanaged. In 2011, the PHC concentrations were below detection limits in all soils tested and the originally planted grasses had been replaced by volunteer plant species that had colonized the site. Here, we sought to understand how the original treatments influenced the structure of prokaryotic communities associated with plant species that colonized the soils and to assess the interactions between the rhizospheric and endophytic communities of the colonizing vegetation 20 years after the experiment was established. Metataxonomic analysis performed using 16S rRNA gene sequencing revealed that the original type of contaminated soil and phytoremediation strategy influenced the structure of both rhizospheric and endophytic communities of colonizing plants, even 20 years after the treatments were applied and following the disappearance of the originally planted grasses. Our findings demonstrate that the choice of initial phytoremediation strategy drove the succession of microorganisms associated with the colonizing vegetation. The outcome of this study provides new insight into the establishment of plant-associated microbial communities during secondary succession of subarctic areas previously contaminated by PHCs and indicates that the strategies for restoring these ecosystems influence the plant-associated microbiota in the long term. IMPORTANCE Subarctic ecosystems provide key services to local communities, yet they are threatened by pollution caused by spills and disposal of petroleum waste. Finding solutions for the remediation and restoration of subarctic soils is valuable for reasons related to human and ecosystem health, as well as environmental justice. This study provides novel insight into the long-term succession of soil and plant-associated microbiota in subarctic soils that had been historically contaminated with different sources of PHCs and subjected to distinct phytoremediation strategies. We provide evidence that even after the successful removal of PHCs and the occurrence of secondary succession, the fingerprint of the original source of contamination and the initial choice of remediation strategy can be detected as a microbial legacy in the rhizosphere, roots, and shoots of volunteer vegetation even 2 decades after the contamination had occurred. Such information needs to be borne in mind when designing and applying restoration approaches for PHC-contaminated soils in subarctic ecosystems.

Progressive belowground soil development associated with sustainable plant establishment during copper mine waste revegetation

Critical to the environmental sustainability of hard rock mining is the reclamation of disturbed lands following mine closure through revegetation. Improved understanding of associations between above- and belowground processes that characterize successful plant establishment is critical to the implementation of more efficient revegetation strategies for nutrient-poor mine waste materials. The specific objective of this five-year temporal study was to identify progressive biotic and abiotic indicators of primary soil development on mine waste rock (WR) on a slope hydroseeded with native plant species, and to quantify comparative effects of plant lifeform on soil development. Aboveground plant diversity and belowground substrate properties were measured annually at 67 m intervals along transects following the slope contour. Seeded WR was compared to unseeded WR and the adjacent native ecosystem. A temporal increase in WR microbial biomass was observed in seeded WR relative to unseeded areas. Microbial community analysis found the unseeded WR to be defined by oligotrophic microbes, whereas targeted grass and shrub root zone samples demonstrated significant increases in specific cellulose and lignin degrading and N-cycling phylotypes. More extensive chemical and biological fertility development was observed in shrub root zones relative to grass. Ten chemical and biological indicators increased significantly in shrub WR relative to unseeded WR, whereas grass WR was only enriched in bacterial 16S rRNA gene copy number/g substrate and bacterial/archaeal and fungal diversity. In addition, the shrub root zone had significantly higher nitrogen-cycling potential than grass root zones or unseeded WR. Thus, both grasses and shrubs improve belowground WR development; however, shrub establishment had greater fertility outcomes. Concurrent belowground fertility development is critical to sustainable plant establishment. Coupled evaluation of above- and belowground metrics provides an improved quantitative assessment of revegetation progress and a valuable tool to guide management decisions.

Distinct redox state regulation in the seedling performance of Norway maple and sycamore

Norway maple and sycamore, two Acer genus species, have an important ecological value and different sensitivity to stressing factors being currently aggravated by climate change. Seedling growth is postulated to be the main barrier for successful plant establishment under the climate change scenarios. Therefore, the differences in redox regulation during the seedling performance of Norway maple and sycamore were investigated. Seeds of the two Acer species exhibited an identical high germination capacity, whereas seedling emergence was higher in sycamores. PCA analyses revealed that there is more diversification in the leaf characteristics than roots. Norway maple displayed a higher chlorophyll content index (CCI) with a similar leaf mass whereas sycamore seedlings exhibited a higher normalized difference vegetation index (NDVI), higher water content, higher root biomass and higher shoot height. Based on NDVI, sycamore seedlings appeared as very healthy plants, whereas Norway maple seedlings displayed a moderate healthy phenotype. Therefore, redox basis of seedling performance was investigated. The total pool of glutathione was four times higher in sycamore leaves than in Norway maple leaves and was reflected in highly reduced half-cell reduction potential of glutathione. Sycamore leaves contained more ascorbate because the content of its reduced form (AsA) was twice as high as in Norway maple. Therefore, the AsA/DHA ratio was balanced in sycamore leaves, reaching 1, and was halved in Norway maple leaves. Nicotinamide adenine dinucleotide phosphate content was twice as high in sycamore leaves than in Norway maples; however, its reduced form (NADPH) was predominant in Norway maple seedlings. Norway maple leaves exhibited the highest anabolic and catabolic redox charge. The higher reduction capacity and the activity of NADPH-dependent reductases in Norway maple leaves possibly resulted in higher CCI, whereas the larger root system contributed to higher NDVI in sycamore. The different methods of controlling redox parameters in Acer seedlings grown at controlled conditions provided here can be useful in understanding how tree species can cope with a changing environment in the future.

'Root of all success': Plasticity in root architecture of invasive wild radish for adaptive benefit.

Successful plant establishment in a particular environment depends on the root architecture of the seedlings and the extent of edaphic resource utilization. However, diverse habitats often pose a predicament on the suitability of the fundamental root structure of a species that evolved over a long period. We hypothesized that the plasticity in the genetically controlled root architecture in variable habitats provides an adaptive advantage to worldwide-distributed wild radish (Raphanus raphanistrum, Rr) over its close relative (R. pugioniformis, Rp) that remained endemic to the East Mediterranean region. To test the hypothesis, we performed a reciprocal comparative analysis between the two species, growing in a common garden experiment on their native soils (Hamra/Sandy for Rr, Terra Rossa for Rp) and complementary controlled experiments mimicking the major soil compositions. Additionally, we analyzed the root growth kinetics via semi-automated digital profiling and compared the architecture between Rr and Rp. In both experiments, the primary roots of Rr were significantly longer, developed fewer lateral roots, and showed slower growth kinetics than Rp. Multivariate analyses of seven significant root architecture variables revealed that Rr could successfully adapt to different surrogate growth conditions by only modulating their main root length and number of lateral roots. In contrast, Rp needs to modify several other root parameters, which are very resource-intensive, to grow on non-native soil. Altogether the findings suggest an evo-devo adaptive advantage for Rr as it can potentially establish in various habitats with the minimal tweak of key root parameters, hence allocating resources for other developmental requirements.

Assessing Seedbank Longevity and Seed Persistence of the Invasive Tussock Grass Nassella trichotoma Using in-Field Burial and Laboratory-Controlled Ageing

The ability to produce highly dense and persistent seedbanks is a major contributor to the successful widespread establishment of invasive plants. This study seeks to identify seed persistence and seedbank longevity for the invasive tussock grass Nassella trichotoma (Nees.) Hack. ex Arechav in order to recommend management strategies for preventing re-emergence from the seedbank. To determine the seedbank longevity and persistence, two experiments were conducted: (i) seeds were buried at four depths (0, 1, 2, and 4 cm) and collected and assessed for viability, seed decay, and in-field germination after 6, 9, 12, 15, and 18 months of field burial; and (ii) seeds were exposed to artificial ageing conditions (60% RH and 45 °C) for 1, 2, 5, 9, 20, 30, 50, 75, 100, and 120 days, and viability was determined through germination tests and tetrazolium tests. Less than 10% of the seeds collected after 12 months of in-field burial were viable. The artificial ageing treatment found germination declined to 50% after 5.8 days, further suggesting that N. trichotoma seeds are short lived. The results from both experiments indicate that N. trichotoma has a transient seedbank, with less than 10% of the seeds demonstrating short-term persistence. It is likely the persistent seeds beyond 12 months were exhibiting secondary dormancy as viable seeds did not germinate under optimal germination conditions. The “Best Practice Guidelines” recommend monitoring for seedbank recruitment for at least three years after treating N. trichotoma infestations. The results of this study support this recommendation as a small proportion of the seeds demonstrated short-term persistence.

Nano-priming: Impression on the beginner of plant life

In the interest to assist plant growth and bolster their strength to deal with the environmental cues, priming has been revealed to play a remarkable role through induction of several metabolic and physiological alterations. It can be delineated as a physiological process of prompting plants by treating with biological/chemical priming agents or mild stress to display better growth biomarkers and stress resistance in case of repeated stress encounters. Priming of seeds has been of great interest for researchers in recent years which brings about changes in seed metabolism to support the successful establishment of plants in its environment through faster and more prominent seed germination and growth of developing seedlings. The conspicuously displayed rise in applications of nanotechnology in agriculture has also stirred up the research on nano-priming of plants. Nanoparticles (NPs) have appeared to be more proficient in influencing growth, quality, yield, and reactive oxygen species (ROS) homeostasis in plant seeds than other methods of priming such as priming with the bulk materials or hydro-priming. However, there is a need to opt-out NPs exhibiting toxic effects on seed germination and seedling growth for deliberate priming while understanding their possible repercussions on plant as well as human health. Therefore, this article aims to present the recent research conducted in the field of nano-priming of seeds of different plants along with recommendations for future research.