Hasil untuk "Plant ecology"

F. Bazzaz, N. Chiariello, P. D. Coley et al.

G. Carpenter, A. Gillison, J. Winter

P. Kayastha, M. M. Bartylak, T. Bartylak et al.

Using integrative taxonomy, we describe a new species from Ribeira Brava, Madeira (Portugal), belonging to the genus Pseudechiniscus and subgenus Meridioniscus. The new species, Pseudechiniscus (Meridioniscus) goldsteini sp. nov. is described based on morphological and morphometric data obtained through both Phase Contrast Light Microscopy (PCM) and Scanning Electron Microscopy (SEM). In addition, genetic distinctiveness was assessed by calculating p-distances between Pse. (Mer.) goldsteini sp. nov. and other species within the genus Pseudechiniscus using two DNA markers: one nuclear marker (28S rRNA) and one mitochondrial marker (COI). Morphologically, the new species most closely resembles Pse. (Mer.) angelusalas, Pse. (Mer.) dastychi, Pse. (Mer.) dreyeri, Pse. (Mer.) indistinctus, Pse. (Mer.) mascarenensis, and Pse. (Mer.) wallacei. However, it can be distinguished from these species primarily by differences in the details of its ventral sculpture, configuration of granulation patches and the length of head appendages.http://zoobank.org/urn:lsid:zoobank.org:pub:E7FB8100C210-4850-89CA-AB8561A8FE1B

M. Rejmánek

R. S. D. de Souza, Jaderson Silveira Leite Armanhi, P. Arruda

Plants teem with microorganisms, whose tremendous diversity and role in plant–microbe interactions are being increasingly explored. Microbial communities create a functional bond with their hosts and express beneficial traits capable of enhancing plant performance. Therefore, a significant task of microbiome research has been identifying novel beneficial microbial traits that can contribute to crop productivity, particularly under adverse environmental conditions. However, although knowledge has exponentially accumulated in recent years, few novel methods regarding the process of designing inoculants for agriculture have been presented. A recently introduced approach is the use of synthetic microbial communities (SynComs), which involves applying concepts from both microbial ecology and genetics to design inoculants. Here, we discuss how to translate this rationale for delivering stable and effective inoculants for agriculture by tailoring SynComs with microorganisms possessing traits for robust colonization, prevalence throughout plant development and specific beneficial functions for plants. Computational methods, including machine learning and artificial intelligence, will leverage the approaches of screening and identifying beneficial microbes while improving the process of determining the best combination of microbes for a desired plant phenotype. We focus on recent advances that deepen our knowledge of plant–microbe interactions and critically discuss the prospect of using microbes to create SynComs capable of enhancing crop resiliency against stressful conditions.

S. Jacquemoud, S. Ustin

Plant leaves collectively represent the largest above-ground surface area of plant material in virtually all environments. Their optical properties determine where and how energy and gas exchange occurs, which in turn drives the energy budget of the planet, and defines its ecology and habitability. This book reviews the state-of-the-art research on leaf optics. Topics covered include leaf traits, the anatomy and structure of leaves, leaf colour, biophysics and spectroscopy, radiometry, radiative transfer models, and remote and proximal sensing. A physical approach is emphasised throughout, providing the necessary foundations in physics, chemistry and biology to make the context accessible to readers from various subject backgrounds. It is a valuable resource for advanced students, researchers and government agency practitioners in remote sensing, plant physiology, ecology, resource management and conservation.

Matthias Ulbricht, Peter Biber, Thomas Rötzer et al.

We examined the effects of drought-induced stress on foliar litter production, nutrient contents, and nutrient masses in mature European beech (Fagus sylvatica [L.]) and Norway spruce (Picea abies [L.] Karst.) over a two-year period (October 2015–September 2017) in southern Bavaria. A rainfall exclusion experiment was conducted with six control plots receiving normal rainfall and six roof plots excluding rainfall. Abscised leaf and needle biomass, as well as the contents and masses of calcium (Ca), potassium (K), magnesium (Mg), nitrogen (N), and phosphorus (P), were monitored across two non-vegetation periods (October–February: NV1, NV2) and two vegetation periods (March–September: V1, V2).Foliar litter on control plots (set at 100 %) was 4000, 329, 4501, 403 kg/ha for European beech and 3534, 1146, 1352, 607 kg/ha for Norway spruce across the four observation periods (NV1, V1, NV2, V2). Roof plots yielded 2917 (73 %), 364 (111 %), 3710 (82 %), 358 (89 %) kg/ha for European beech and 5841 (165 %), 1040 (91 %), 899 (67 %), 447 (74 %) kg/ha for Norway spruce. Significant differences between control and roof plots were observed only during NV1.Foliar K contents were significantly lower under drought in both species. For European beech, values were 2.83, 3.83, 2.76, 4.37 g/kg (control plots), compared to 2.38 (84 %), 3.08 (80 %), 2.30 (83 %), 4.01 (92 %) g/kg (roof plots). For Norway spruce, values were 2.64, 2.77, 2.51, 2.13 g/kg (control plots), compared to 2.26 (86 %), 2.33 (84 %), 2.01 (80 %), 1.66 (78 %) g/kg (roof plots). Drought also significantly decreased foliar Ca content in Norway spruce during NV2, from 8.61 to 7.04 g/kg (82 %).Foliar nutrient masses aligned more closely with biomass abscission patterns than with nutrient translocation patterns. European beech predominantly exhibited significantly reduced abscised nutrient masses under drought during NV1 and NV2, while Norway spruce initially showed significantly increased abscised nutrient masses in NV1, followed by a marked decline in subsequent seasons.We concluded that European beech responded to drought stress by reducing foliage biomass production, suggesting a potential acclimation strategy, whereas Norway spruce mitigated water loss through transpiration by shedding its needles. However, Norway spruce failed to compensate for the initial high needle losses by regenerating sufficient new needles, indicating its lower resilience to drought.

Jintu Kumar Bania, Jyotish Ranjan Deka, Arnab Paul et al.

Tea [Camellia sinensis (L.) O. Kuntze], one of the most widely consumed beverages globally, is cultivated on over 5.27 million ha of land, is a source of income for low-income families. However, the effect of future emission scenarios on the suitability of areas for tea production is poorly understood, and any adverse outcome under climate change scenarios can affect millions of households and the tea industry. We assess the current and future habitat suitability of tea across the globe under two shared socio-economic pathways (SSPs = SSP2.4-5 and SSP5.8-5) for 2050 and 2070 and determine the key factors that influence tea distribution. We employed an ensemble of five species distribution models to assess the tea distribution. Overall, the highly suitable areas for tea production will experience some decline in 11 out of the top 20 tea-producing countries by 2050 and 2070 under both SSP2-4.5 (moderate emission scenarios) and SSP5-8.5 (high emission scenarios) relative to the current conditions. However, marginally suitable areas will increase by 39 % by 2050 and 72 % by 2070 under the high-emission scenario. Some tea-producing countries such as Argentina, Malawi and Tanzania are projected to experience a 60-78 % reduction of their highly suitable area for tea, while Iran, Rwanda, Thailand, and Turkey will witness an 11-27 % increase by 2050. Precipitation of the warmest quarter, mean temperature of the driest quarter, soil pH, isothermality, and mean temperature of the wettest quarter are the key variables influencing the current distribution of tea. Here, we provide projections of changes in the highly suitable area for the top 20 tea-producing countries in the world by 2050, which we hope will serve as baseline information for decision-makers to make evidence-informed choices. Since the present study was performed at a coarse scale, it is strongly recommended that future studies produce fine-scale projections with regional climate and ground-truth tea production data.

Parag Bhople, David Wall, Karl Richards et al.

Managing agroecosystems to enhance soil organic carbon (SOC) storage is important for mitigating climate change. However, the transformation of SOC is intimately connected to nutrient cycling, particularly nitrogen (N) and phosphorus (P). While P constraints on plant growth are known, their effects on carbon (C) and N cycling remain uncertain. The study uses several long-term experiments (LTEs) to determine the importance of N-P interactions and the optimal C:N:P stoichiometry for long-term SOC stocks in managed agricultural systems. The aim was to determine the influence of multi-decadal P fertilisation on SOC stocks and stoichiometric interactions of C, N and P in agricultural soils (up to 50 cm) across different soil textural classes and land uses. For this, the soils were sampled at three depths 0–10, 10–30 and 30–50 cm from six LTEs in Europe (three grasslands and three arables) to determine soil physico-chemical properties. The results showed comparable SOC stocks in contrasting P treatments across land uses. In grasslands, SOC stocks at 0–50 cm depth ranged from 9.7 to 40.6 t C ha−1 while in arable sites, they were between 11.0 and 48.3 t C ha−1. The SOC stocks did not vary significantly across P treatments indicating that long-term P fertilisation did not affect C storage. Grassland sites had higher SOC stocks in the 0–10 cm, while at arable sites they were higher at 10–30 cm depths. The maximum predicted SOC stock of 30.9 t C ha−1 was with SOC/TN (total nitrogen) ratio of 10.1 and SOC/TP (total phosphorus) ratio of 32.6 in grassland sites, while these ratios were 10.9 and 29.4, respectively, in arable sites, where the predicted maximum SOC stock was 33.3 t C ha−1. Overall, the study shows that the long-term phosphorus fertilisation of grassland and arable soils did not affect SOC stocks at the studied LTEs.

Zhongkai Chen, Jun Tang, Dan Lv et al.

Cd contamination poses a serious threat to maize production by inducing oxidative stress and disrupting vital physiological processes. This study systematically investigated the time-dependent dynamic responses of maize seedlings to Cd stress. Physiological assessments revealed that Cd stress triggered excessive accumulation of ROS. MDA levels in roots increased significantly at all time points, whereas shoots exhibited a delayed accumulation pattern. The activities of antioxidant enzymes (SOD, CAT, and POD) displayed distinct tissue- and time-specific responses. Transcriptomic profiling identified 8789 DEGs that exhibited sustained expression changes across stress durations.These DEGs were significantly enriched in pathways related to photosynthesis, secondary metabolism, and antioxidant defense. Metabolomic analyses detected 286, 158, and 371 DAMs at corresponding time points. Key metabolites, such as salicylic alcohol glucoside and coumaroylquinic acid, were strongly associated with oxidative stress regulation. Integrated transcriptome–metabolome analysis demonstrated that plant hormone signaling, together with the TCA cycle, glycerophospholipid metabolism, phenylpropanoid biosynthesis, and glutathione metabolism, coordinately contribute to Cd detoxification. This occurs by forming a multilayered defense network. These findings reveal the time-dependent adaptive strategies of maize under Cd stress and provide valuable insights for the development of Cd-tolerant maize cultivars.

G. Zotz

Pooja Singh, Amantika Singh, Krishna Kumar Choudhary

Ultraviolet-B (UV-B) radiation from the past few decades has been widely studied due to the substantial depletion of the stratospheric ozone (O3) layer, causing morphological, physiological, cytological, and biochemical alterations in plants. As a potent abiotic stress factor, enhanced reactive oxygen species (ROS) generation has been flagged as a key factor under UV-B stress. UV-B adversely affects plant growth and development. Plants have evolved defense strategies under UV-B stress to counteract these detrimental effects. The most common protective response is an accumulation of secondary metabolites. These provide photoprotection by acting as UV-B absorbing compounds through quenching ROS and reactive nitrogen species (RNS).UV-B-induced metabolites share a common origin in the phenylpropanoid biosynthetic pathway. These phenylpropanoids induced via UV Resistance Locus 8 (UVR8) signaling are transcriptionally regulated by MYB transcription factors (TFs) and are efficiently transported to different cellular and membrane-limited compartments. The accumulation of metabolites like flavonoids, anthocyanins, lignins and tannins in plants marks the importance of its metabolism in UV-B tolerance mechanism. Plant species responded differently to increased UV-B exposure in terms of phenylpropanoid concentration. Apart from UV-B screening agents, these are also potent ROS scavengers due to their structural composition and less reactive nature. The dynamic balance between ROS accumulation under UV-B stress and its metabolism via phenylpropanoids holds the key to the stress tolerance attributes of a plant. The present review focuses on the UV-B-induced secondary metabolites in plants, their biosynthesis, and defense strategies that will help in the elucidation of medicinally important bioactive compounds as well as in the development of UV-B tolerant plants.

Utpal Barua, Mokidul Islam, Samir Medhi

A study was undertaken during the year 2020–2021 in Kyrdem and Sohriewblei villages, Ri-Bhoi district, Meghalaya, India to find out the level of awareness and adoption of climate resilient horticultural technologies. The selected villages had been adopted under National Initiative on Climate Resilient Agriculture (NICRA) project since 2011-2020. A sample size of 100 farmers (50 from each village) who were actively involved in horticultural activities was selected randomly. A well-structured, pre-tested interview schedule was employed for the data collection. The study revealed that the awareness level was recorded highest in institutional measures (94.2%) followed by horticultural practices (92.4%) and soil and water conservation (89%) measures. The highest adoption level of resilient practices was observed in horticultural practices (83.9%). Out of all respondents 89% were classified as medium category farmers for adoption of climate resilient technologies in both the villages. There was no statistical difference in the adoption level of resilient practices among the farmers of both the villages. Spearman rank correlation (0.730) depicted correlation between awareness and adoption level of horticultural technologies among the selected farmers in both the villages. It could be concluded that in an area like Meghalaya where small size of land holding and fragmented land emerged as main constraint for adoption of modern horticultural technology. Rigorous awareness programme to orient farming community towards scientific proven methods will be able to minimize the adverse effects of climate change.

Sujuan Xu, Ze Wu, Jingya Zhao et al.

Leaf disc transformation is one of the traditional methods that are now widely used in chrysanthemum with highly economical and ornamental value in world flower production, but it depends on plant genotypes and is time consuming and complicated. In addition, the transformation success rate of this method is low, generally ranging from 0.1% to 6.25%. Therefore, a highly efficient transformation system is needed. In this study, we are the first to establish a high-efficient chrysanthemum Agrobacterium-mediated transformation system via vacuum infiltration. Chrysanthemum stem internode explants were used as research material and CmLEC1 was used as a reporter gene. After approximately 3 months of culture and selection, the positive transgenic plants were obtained. Additionally, the positive probability was about 42%. The transformation efficiency was up to 37.7%, and if the escapes were removed, it was 16%. Furthermore, stable expression of CmLEC1 in transgenic 'Yuhualuoying' was confirmed by qRT-PCR analysis. These results suggest that this genetic transformation system via vacuum infiltration of chrysanthemum stem internode is highly efficient and convenient, and much better than traditional leaf disc transformation, and it will play an important role in chrysanthemum transformation and functional genetics research.

Li Zhang, Hai-Li Zhang, Yukai Chen et al.

Hopea hainanensis is a large evergreen tree belonging to the family Dipterocarpaceae. It is currently listed as an endangered species on the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species. It is found primarily on China’s Hainan Island and northern Vietnam. To protect the plant species with extremely small populations Hopea hainanensis and understand its community stability and the inter-specific associations between Hopea hainanensis and other occurring species, we set up 16 quadrats in the areas where wild Hopea hainanensis populations occurred on Hainan Island to investigate the composition of plant species in the quadrats. We used the M. Godron Community stability index to quantify community stability. Based on the two × two contingency tables, the statistic X2, association coefficient (AC), and Pearson correlation coefficient (PCC), percentage co-occurrence (PC), and OI index (OI) analyze the degree of association between Hopea hainanensis and the dominant species in each layer. The results showed that the relationship between Hopea hainanensis and the dominant species in the community was not significant. In addition, there were both positive and negative associations between Hopea hainanensis and other examined six tree species, positive associations with 13 shrub species, positive associations with two herbs, and negative associations with species of 7 species. The connection between Hopea hainanensis and herbs is more complex than that between trees, shrubs, and the dominant species. M. Godron’s stability analysis showed that the community where Hopea hainanensis occurred is relatively unstable (36.84/63.16). The ecology is somewhat fragile, indicating that the community is still at the early or middle stage of competing with other species for resource utilization. The stability of community structure and function is a suitable environment for Hopea hainanensis and finally achieve the purpose of adequate protection, we should choose species with strong positive associations for protecting and recovering Hopea hainanensis.

Iva Šikuten, Bernard Kozina, Ana Jeromel et al.

Global wine market is undergoing the changes in the consumer preferences, with the rising popularity of the sparkling wines. The similar trend is observed in the Republic of Croatia. Graševina, the most important white grapevine variety, showed great adaptability to climate conditions. The results of clonal selection pointed out the clone OB-435 as suitable for sparkling wine production. Thus, the aim of this study was to evaluate the quality of OB-435 sparkling wines. The sparkling wines were produced by traditional method and different concentrations of dosage were added- 1.5 mL L-1 (GR-1,5) and 2.5 mL L-1 (GR-2,5). The basic chemical parameters and sensory evaluation of sparkling wines, confirmed the suitability of this clone for sparkling wine production in the conditions of continental winegrowing hill Zagreb. Sparkling wine with lower dosage concentration was evaluated as better by different sensory methods, regardless the evaluators´ experiences.

Jingjing Tian, Qian Xing, Tingting Jing et al.

Plants have the potency to regenerate adventitious roots from aerial organs after detachment. In Arabidopsis thaliana, de novo root regeneration (DNRR) from leaf explants is triggered by wounding signaling that rapidly induces the expression of the ETHYLENE RESPONSE FACTOR (ERF) transcription factors ERF109 and ABR1 (ERF111). In turn, the ERFs promote the expression of ASA1, an essential enzyme of auxin biosynthesis, which contributes to rooting by providing high levels of auxin near the wounding side of the leaf. Here, we show that the loss of the epigenetic regulator ULTRAPETALA1 (ULT1), which interacts with Polycomb and Trithorax Group proteins, accelerates and reinforces adventitious root formation. Expression of ERF109 and ASA1 was increased in ult1 mutants, whereas ABR1 was not significantly changed. Cultivation of explants on media with exogenous auxin equates adventitious root formation in wild-type with ult1 mutants, suggesting that ULT1 negatively regulates DNRR by suppressing auxin biosynthesis. Based on these findings, we propose that ULT1 is involved in a novel mechanism that prevents overproliferation of adventitious roots during DNRR.

T. Smith, R. Smith

O. Petrini, T. Sieber, L. Toti et al.

Renan Silva Arruda, Natália Pessoa Noyma, Leonardo de Magalhães et al.

Combining coagulants with ballast (natural soil or modified clay) to remove cyanobacteria from the water column is a promising tool to mitigate nuisance blooms. Nevertheless, the possible effects of this technique on different toxin-producing cyanobacteria species have not been thoroughly investigated. This laboratory study evaluated the potential effects of the “Floc and Sink” technique on releasing microcystins (MC) from the precipitated biomass. A combined treatment of polyaluminium chloride (PAC) with lanthanum modified bentonite (LMB) and/or local red soil (LRS) was applied to the bloom material (mainly <i>Dolichospermum circinalis</i> and <i>Microcystis aeruginosa</i>) of a tropical reservoir. Intra and extracellular MC and biomass removal were evaluated. PAC alone was not efficient to remove the biomass, while PAC + LMB + LRS was the most efficient and removed 4.3–7.5 times more biomass than other treatments. Intracellular MC concentrations ranged between 12 and 2.180 µg L⁻¹ independent from the biomass. PAC treatment increased extracellular MC concentrations from 3.5 to 6 times. However, when combined with ballast, extracellular MC was up to 4.2 times lower in the top of the test tubes. Nevertheless, PAC + LRS and PAC + LMB + LRS treatments showed extracellular MC concentration eight times higher than controls in the bottom. Our results showed that Floc and Sink appears to be more promising in removing cyanobacteria and extracellular MC from the water column than a sole coagulant (PAC).