High Plant Research Articles

Multiomics and biotechnologies for understanding and influencing cadmium accumulation and stress response in plants.

Cadmium (Cd) is one of the most toxic heavy metals faced by plants and, additionally, via the food chain, threatens human health. It is principally dispersed through agro-ecosystems via anthropogenic activities and geogenic sources. Given its high mobility and persistence, Cd, although not required, can be readily assimilated by plants thereby posing a threat to plant growth and productivity as well as animal and human health. Thus, breeding crop plants in which the edible parts contain low to zero Cd as safe food stuffs and harvesting shoots of high Cd-containing plants as a route for decontaminating soils are vital strategies to cope with this problem. Recently, multiomics approaches have been employed to considerably enhance our understanding of the mechanisms underlying (i) Cd toxicity, (ii) Cd accumulation, (iii) Cd detoxification and (iv) Cd acquisition tolerance in plants. This information can be deployed in the development of the biotechnological tools for developing plants with modulated Cd tolerance and detoxification to safeguard cellular and genetic integrity as well as to minimize food chain contamination. The aim of this review is to provide a current update about the mechanisms involved in Cd uptake by plants and the recent developments in the area of multiomics approach in terms of Cd stress responses, as well as in the development of Cd tolerant and low Cd accumulating crops.

Effect of Herbal Kunapajala and Different Organic Manures on Plant Growth, Quality and Yield of Withania Somnifera L. Dunal

Effect of Herbal Kunapajala and Different Organic Manures on Plant Growth, Quality and Yield of Withania Somnifera L. Dunal

Characterization And Genetic Relationship of Several Tomato (Solanum lycopersicum L.) Genotypes from Various Regions

The research aims to obtain information about the morphological characters and genetic relationships of several tomato genotypes from various regions. The study was conducted from May to October 2023 at the Experimental Garden and Plant Breeding Laboratory, Faculty of Agriculture, University of Riau. The research used a randomized block design (RBD) consisting of eight genotypes and four repeats, and 32 experimental units were obtained. The observations were made to observe some qualitative characters. Qualitative data were analyzed using principal component analysis and cluster analysis to see genetic relationships. The results showed that the Magelang genotype (T27) had a high average plant fruit weight of 619.74 g, the Pane tongah (T24) had an average thick fruit flesh of 6.05 mm, the Silimakuta (T22) had an average large fruit size of 63.28 g. In contrast, the Purba (T25) had an average number of large planting fruits of 15.41 pieces. Grouping eight tomato genotypes based on clustering of MC1 and MC2 and cutting the dendrogram at a 90% similarity rate resulted in six groups. Group One consists of three genotypes, specifically Silimakuta (T22), Alahan Panjang (T26), and Magelang (T27). Group Two has Raya (T23), Group Three has Purba (T25), Group Four has Pane tongah (T24), group five has Servo F1 and group six has Ratna. The closest kinship based on the smallest euclidiean distance value is the Silimakuta (T22) and Alahan panjang (T26), with a value of 19.44. The genotypes with the farthest similarity are Raya (T23) and Purba (T25) because they have a 46.24 genetic distance

Coordinated control for the auricle asymmetric development by ZmIDD14 and ZmIDD15 fine-tune the high-density planting adaption in maize.

Multiple distinct specialized regions shape the architecture of maize leaves. Among them, the fringe-like and wedge-shaped auricles alter the angle between the leaf and stalk, which is a key trait in crop plant architecture. As planting density increased, a small leaf angle (LA) was typically selected to promote crop light capture efficiency and yield. In the present study, we characterized two paralogous INDETERMINATE DOMAIN (IDD) genes, ZmIDD14 and ZmIDD15, which contain the Cys2-His2 zinc finger domain and function redundantly to regulate auricle development and LA in maize. Loss-of-function mutants showed decreased LA by reducing adaxial sclerenchyma thickness and increasing the colourless cell layers. In addition, the idd14;idd15 double mutant exhibited asymmetrically smaller auricles, which might cause by a failed maintenance of symmetric expression of the key auricle size controlling gene, LIGULELESS(LG1). The transcripts of ZmIDD14 and ZmIDD15 enriched in the ligular region, where LG1 was highly expressed, and both proteins physically interacted with ZmILI1 to promote LG1 transcription. Notably, the idd14;idd15 enhanced the grain yield of hybrids under high planting densities by shaping the plant architecture with a smaller LA. These findings demonstrate the functions of ZmIDD14 and ZmIDD15 in controlling the abaxial/adaxial development of sclerenchyma in the midrib and polar development along the medial-lateral axes of auricles and provide an available tool for high-density and high-yield breeding in maize.

Patch growth of seashore paspalum (Paspalum vaginatum) treated with inorganic fertilizer and organic biostimulant

Inorganic fertilizers are often used in the United States in golf courses putting green maintenance. We used milled plant biomass on putting greens to test the hypothesis that organic biostimulants used in putting green maintenance can achieve similar results as inorganic fertilizers. Dilapidated putting greens, #4 and #14, with conspicuous patches at the L.E. Ramey Golf Course in Kingsville, TX, were selected for the study. Each green was split in half with one half selected for treatment and the other half maintained as the control and treated with NPK. Milled Medicago sativa L. mixed with milled high auxin-containing plant species in a ratio of 10:1 was used to test the hypothesis. The mixture was applied in the bio-treated section of the two greens while the golf course management continued to apply inorganic fertilizers on the control section of the study greens. Patch count on the greens was conducted once a week utilizing a randomly placed 1 by 1 m quadrant. Also, soil moisture measurement was taken twice a week on the greens to understand soil moisture retention due to the treatments. Patch count indicates that the bio-treated sections grew and filled significantly faster than the sections treated with inorganic fertilizers. Regression analysis of data collected between July 13th and July 27th indicates a strong linear biostimulant/patch growth relationship (R2 = 0.75 and 0.92) on Greens #4 and #14 respectively. Also, soil moisture data indicates significantly higher moisture retention on the putting green sections treated with the biostimulant.

MeGT2.6 increases cellulose synthesis and active gibberellin content to promote cell enlargement in cassava.

Cassava, a pivotal tropical crop, exhibits rapid growth and possesses a substantial biomass. Its stem is rich in cellulose and serves as a crucial carbohydrate storage organ. The height and strength of stems restrict the mechanised operation and propagation of cassava. In this study, the triple helix transcription factor MeGT2.6 was identified through yeast one-hybrid assay using MeCesA1pro as bait, which is critical for cellulose synthesis. Over-expression and loss-of-function lines were generated, and results revealed that MeGT2.6 could promote a significant increase in the plant height, stem diameter, cell size and thickness of SCW of cassava plant. Specifically, MeGT2.6 upregulated the transcription activity of MeGA20ox1 and downregulated the expression level of MeGA2ox1, thereby enhancing the content of active GA3, resulting in a large cell size, high plant height and long stem diameter in cassava. Moreover, MeGT2.6 upregulated the transcription activity of MeCesA1, which promoted the synthesis of cellulose and hemicellulose and produced a thick secondary cell wall. Finally, MeGT2.6 could help supply additional substrates for the synthesis of cellulose and hemicellulose by upregulating the invertase genes (MeNINV1/6). Thus, MeGT2.6 was found to be a multiple regulator; it was involved in GA metabolism and sucrose decomposition and the synthesis of cellulose and hemicellulose.

Evaluation of soil microbial activity after application of Paenibacillus polymyxa-based biofertilizer in wheat field experiment

The establishment of eco-friendly principles in agriculture requires, from one side, a reduced dependence on chemical fertilizers, pesticides and herbicides, and on the other, a maintenance of consistent yield and high plant productivity. Such substantial shift in the contemporary agricultural practices can be achieved only if a wide variety of alternative options is available. Furthermore, in order to become part of agricultural practices these options have to be affordable in a broad scale and effective against the loss of biodiversity and reduced soil fertility. The current study presents data about the metabolic activity and microbial community` structure in two soil samples – one treated with chemical fertilizer and another treated with chemical fertilizer reduced by 25% dose and supplemented with commercially available biofertilizer. Metabolic activity and properties of microbial soil communities were assessed by the BIOLOG® EcoPlate technique. The estimated parameters included average well-color development (AWCD) and utilisation of six guilds of substrates. Several functional indexes that are used for evaluation of community diversity and evenness were also estimated. The AWCD, expressed either as total activity or as guilds utilisation during the EcoPlate incubation period of seven days did not reveal significant difference between variants. However, most of the estimated functional indexes consistently indicated higher microbial diversity and more balanced structure of microbial community in the biofertilizer-supplemented variant. The results clearly implied that the biofertilizer based on nitrogen-fixing bacteria can positively influence the structure of soil communities and its application could be beneficial for soil fertility and plant productivity. Keywords: diazotroph, biofertilizer, BIOLOG® EcoPlate, functional indexes, metabolic activity, microbial communities

Effect of high plant protein diet supplemented with Lysophospholipids-butyrate on the growth performance, liver health and intestinal morphology of Largemouth bass (Micropterus salmoides)

This study was conducted to evaluate the effects of dietary supplementation with lysophospholipids-butyrate (LPB) in a high plant protein diet on the growth performance, liver health, and intestinal morphology of Largemouth bass (Micropterus salmoides). Three experimental diets were formulated: a positive control diet (PC) containing 15.00 % soybean meal (SBM) and 13 % chicken meal；a high-plant-protein diet (HPP) with 28.00 % SBM; a diet (LPB) supplemented LPB at 0.1 % in HPP. Largemouth bass with an average initial body weight of 9.3 g were fed for 60 days, with 4 replicates per group and 20 fish per replicate. The results demonstrated that the HPP group exhibited significantly lower final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) compared to the PC group. Moreover, the HPP diet induced a notable increase in liver collagen fiber and liver lipid content, which was alleviated by LPB supplementation. In comparison to the HPP group, the LPB group showed significant increases in serum albumin and albumin/globulin, along with a significant decrease in alanine aminotransferase activity (P < 0.05). Compared with the PC group, the mRNA levels of acetyl-CoA carboxylase-1 (ACC-1), diacylglycerol acyltransferase (DGAT), carnitine palmitoyl transferase-1 (CPT-1) and tumor necrosis factor-α (TNF-α) in HPP group were increased significantly (P < 0.05), while adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) as well as apoptotic gene B-cell lymphoma-2 (Bcl-2) were significantly down-regulated. The mRNA levels of fatty acid synthase (FAS), ACC-1, peroxisome proliferator activated receptor-α (PPAR-α), ATGL, interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and Bcl-2 were up-regulated (P < 0.05), while DGAT and TNF-α were down-regulated in the LPB supplemented groups than that in the HPP group (P < 0.05). In conclusion, the supplementation of 0.1 % LPB can alleviate liver lipid accumulation and fibrosis caused by high level of soybean meal.

Recent advances in paclitaxel biosynthesis and regulation.

Paclitaxel (PTX) is a high value plant natural product (PNP) derived from Taxus (yew) species. This plant secondary metabolite (PSM) and its derivatives constitute a cornerstone for the treatment of an increasing variety of cancers. New applications for PTX also continue to emerge, further promoting demand for this WHO designated essential medicine. Here we review recent advances in our understanding of PTX biosynthesis and its cognate regulation, which have been enabled by the development of transcriptomic approaches and the recent sequencing and annotation of three Taxus genomes. Collectively, this has resulted in the elucidation of two functional gene sets for PTX biosynthesis, unlocking new potential for the use of heterologous hosts to produce PTX. Knowledge of the PTX pathway also provides a valuable resource for understanding the regulation of this key PSM. Epigenetic regulation of PSM in plant cell culture (PCC) is a major concern for PTX production, given the loss of PSM production in long-term cell cultures. Recent developments aim to design tools for manipulating epigenetic regulation, potentially providing a means to reverse the silencing of PSM caused by DNA methylation. Exciting times clearly lie ahead for our understanding of this key PSM and improving its production potential.

Using faecal nitrogen as a marker to estimate intake and digestibility in sheep fed multi-species native forage

Livestock production in southern South America heavily relies on extensive native grasslands, characterized by high plant species diversity, which makes estimating forage digestibility and intake by ruminants in this pastoral ecosystem challenging. Therefore, the aim of this study was to develop regression models to establish the relationship between total faecal nitrogen excretion (FNe) and organic matter (OM) intake, and faecal nitrogen content (FNc) and OM digestibility in sheep fed multi-species native forage. In a completely randomized design, 16 Corriedale sheep averaging 44 kg of body weight (BW) were housed in metabolism cages and received forage in amounts of 15, 20, 25 g of dry matter per kg of BW or ad libitum. During the spring of 2019 and the summer of 2020, four measurement periods were carried out. The sheep had 5 days of adaptation to the metabolism cage, 10 days to adapt to the treatments of amounts of forage offered, and 5 days for intake and digestibility measurements. The forage was harvested once a day, and then the fresh forage was offered at two different times, 8 and 17 h. A linear regression model was developed to estimate OM intake in sheep fed multi-species native forage based on the FNe [Intake (g OM/sheep/day) = 107.7 + 101.5 × FNe]. An exponential regression model was developed to estimate forage OM digestibility in sheep based on the FNc (Digestibility = 0.31411e0.02995 × FNc). In conclusion, our findings highlight that the OM intake can be precisely estimated using FNe and a reasonably precise estimation of the forage OM digestibility can be reached by assessing FNc in sheep fed a multi-species native forage from the Rio de la Plata region in South America.

Impact of increased protein intake in older adults: a 12-week double-blind randomised controlled trial.

Emerging evidence suggests health-promoting properties of increased protein intake. There is increased interest in plant protein but a dearth of information in relation to its impact on muscle function. The objective of the present work was to examine the impact of intake of different types of proteins on muscle functional parameters including handgrip strength, biomarkers of metabolic health, sleep quality and quality of life in a group of older adults. Healthy men and women aged 50years and older entered a double-blinded, randomised, controlled nutritional intervention study with three parallel arms: high plant protein, high dairy protein and low protein. Participants consumed once daily a ready-to-mix shake (containing 20g of protein in high protein groups) for 12weeks. Changes in handgrip and leg strength, body composition, metabolic health, quality of life and sleep quality were analysed by linear mixed models in an intention-to-treat approach. Eligible participants (n= 171) were randomly assigned to the groups (plant: n= 60, dairy: n= 56, low protein: n= 55) and 141 completed the study. Handgrip strength increased after the intervention (Ptime= 0.038), with no significant difference between the groups. There was no significant difference between groups for any other health outcomes. In a population of older adults, increasing protein intake by 20g daily for 12weeks (whether plant-based or dairy-based) did not result in significant differences in muscle function, body composition, metabolic health, sleep quality or quality of life, compared with the low protein group.

Dynamic regulation of water potential in Juniperus osteosperma mediates ecosystem carbon fluxes.

Some plants exhibit dynamic hydraulic regulation, in which the strictness of hydraulic regulation (i.e. iso/anisohydry) changes in response to environmental conditions. However, the environmental controls over iso/anisohydry and the implications of flexible hydraulic regulation for plant productivity remain unknown. In Juniperus osteosperma, a drought-resistant dryland conifer, we collected a 5-month growing season time series of in situ, high temporal-resolution plant water potential ( ) and stand gross primary productivity (GPP). We quantified the stringency of hydraulic regulation associated with environmental covariates and evaluated how predawn water potential contributes to empirically predicting carbon uptake. Juniperus osteosperma showed less stringent hydraulic regulation (more anisohydric) after monsoon precipitation pulses, when soil moisture and atmospheric demand were high, and corresponded with GPP pulses. Predawn water potential matched the timing of GPP fluxes and improved estimates of GPP more strongly than soil and/or atmospheric moisture, notably resolving GPP underestimation before vegetation green-up. Flexible hydraulic regulation appears to allow J. osteosperma to prolong soil water extraction and, therefore, the period of high carbon uptake following monsoon precipitation pulses. Water potential and its dynamic regulation may account for why process-based and empirical models commonly underestimate the magnitude and temporal variability of dryland GPP.

Demographic responses to competition with surrounding vegetation in subalpine plant species

Alterations in biotic interactions alongside climatic factors are proposed to affect the extinction risks of alpine and subalpine plant species. We examined the population demography of Primula farinosa along gradients of vegetation coverage to assess how the population viability of high mountain plants would alter in response to changing competitive intensities. Size-based integral projection models were constructed for plots with varying vegetation coverages. Complementary to the demographic survey, the performance of P. farinosa was evaluated in controlled environments when grown with its naturally co-occurring plant, Sanguisorba hakusanensis. In field sites, population growth rates (λ) of P. farinosa declined as surrounding vegetation coverage increased. The means, elasticities, and life-table response experiment (LTRE) contributions of the vital rates also changed, but the alteration patterns depended on the vital rates. Juvenile survival (JS), adult survival (AS), and flowering probability (FP) were lower in plots with denser vegetation while the decrease of AS was not statistically significant. Notably, the elasticity of AS exhibited a positive, whereas the elasticities of JS and FP exhibited negative regression coefficients for vegetative coverage. AS and FP showed more pronounced LTRE contributions in declining λ than JS. Significant reductions in JS and FP were also observed when plants were grown with S. hakusanensis in growth-chamber environments. Both field and chamber studies demonstrated a competitive interaction between P. farinosa and neighboring vegetation, affecting diverse demographic parameters. Altered elasticities would mitigate or exacerbate the impact of decreased mean vital rates on λs in denser vegetation, emphasizing the importance of evaluating both elasticity and the mean of vital rates to predict population persistence under changing biotic interactions.

Commodity risk assessment of Tilia cordata and Tilia platyphyllos plants from the UK.

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Tilia cordata and T. platyphyllos imported from the United Kingdom (UK) as: (a) bundles of budwood/graftwood; (b) 1- to 2-year-old whips, seedlings or transplants; (c) bundles of 1- to 2-year-old cell grown plants; (d) 1- to 7-year-old bare root single plants; and (e) up to 25-year-old single plants in pots, taking into account the available scientific information provided by the UK. A list of pests potentially associated with the commodities was compiled. The relevance of any pest was assessed based on evidence following defined criteria. None of the pests on the list fulfilled all relevant criteria and therefore none were selected for further evaluation. As a result, risk mitigation measures proposed in the technical dossier from the UK were listed, but not further evaluated.

Ethnobotany of Local Foodstuff Plants Used By Bugbug Community In Karangasem, Bali, Indonesia

The aims of this research were (1) Reveal to the diversity of local foodstuff plants utilized by Bugbug community; (2) to analyze traditional knowledge of local foodstuffs plants of Bugbug community; (3) to analyze the Use Value (UV) and Index Cultural Significance (ICS) of local foodstuffs plants. The research was conducted in Bugbug Karangasem, Bali, from January 2021-March 2021. Data were collected using qualitative methods, semi-structured interviews, moderate participation observation, and documentation. Key informants were selected using purposive and snowball sampling to obtain ten key informants and 48 respondents. The use value of plants is calculated by UV, cultural importance with ICS. The level of traditional knowledge was measured by the Phillips and Gentry equations and analyzed by the Kruskal Wallis and Mann Whitney Test. The traditional knowledge of local foodstuff plants was calculated using the Phillips and Gentry equations and analyzed with the Kruskal Wallis and Mann Whitney Test. Traditional knowledge of local foodstuff plants between age groups is different. Meanwhile, knowledge between genders is not different. The diversity of local foodstuff plants in Bugbug Village is 126 species, 47 families, the most families being Musaceae. The high diversity of plants found is caused by specific ecosystems from hilly areas and beaches. The most widely used part of the plant is the fruit. Most plant habitus is an herb. Herbs are easy to grow in various locations and are found in semi-wild status. The highest plant use value and ICS are Arenga pinnata L.

Morphological Trait based Genetic Divergence and Correlation in Barley Genotypes for Drought Tolerance

An experiment was conducted to explore the genetic diversity for the selection and utilization of drought-tolerant barley genotypes in future breeding approaches for yield enhancement. The experimental material comprised thirty barley genotypes planted at the Barley Research Area, Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar, under drought conditions during 2015-16 and 2016-17. All the genotypes were classified into four distinct clusters. Cluster IV occupied the maximum number of genotypes, i.e. 17, followed by cluster I with eight genotypes. Cluster II and III possessed three and two genotypes, respectively. The average inter-cluster distance was found to be highest between clusters II and III (261.7), followed by clusters III and IV (188.1), while the lowest inter-cluster distance was observed between clusters II and IV (73.8). Cluster I, comprised of eight genotypes, exhibited maximum germination per cent. Cluster II consisted of three genotypes, characterized by high initial vigour, early heading and minimum plant height. Two genotypes from cluster III exhibited minimum internode length, longest spike, and maximum number of tillers per meter and were also found promising for the traits viz., culm thickness, number of grains per spike, 1000-grain weight and grain yield per plot. Cluster IV, being the largest one, had 17 genotypes with the characteristic features of early maturity. Number of effective tillers per meter showed significant positive correlation with grain yield per plot. This trait could be used as a key component in the screening and selection of drought-tolerant genotypes. The improvement in barley could be achieved through the use of genotypes namely JB 481 and Lakhan assigned in clusters III. These genotypes might be considered as potential parents to obtain high heterotic response and accordingly better segregant for grain yield under drought condition.

Spermidine regulates wheat grain weight at high planting density by promoting the synthesis of sucrose and starch in inferior grains.

Increasing density is an effective way to enhance wheat (Triticum aestivum L.) yield under limited cultivated areas. However, the physiological mechanisms underlying the reduction in grain weight when density increased are still unclear. Three field experiments were conducted during the 2014-2019 growing seasons to explore the physiological mechanisms by which polyamines affect grain weight formation. The results showed that when wheat planting density exceeded 450 × 104 seedlings ha-1 and 525 × 104 seedlings ha-1, wheat yield tended to decrease. Compared to moderate density (DM, 450 × 104 seedlings ha-1), the filling rate of inferior grains was reduced before 25 days after anthesis (DAA) and the active filling period was shortened by 6.4%-7.4% under high density (DH, 600 × 104 seedlings ha-1), resulting in a loss of 1000-grain weight by 5.4%-8.1%. DH significantly reduced sucrose and starch content in inferior grains at the filling stage. Meanwhile, DH inhibited the activity of key enzymes involved in polyamine synthesis [SAMDC (EC 4.1.1.50) and SpdSy (EC 2.5.1.16)] and induced the activity of ethylene (ETH) precursor synthase, resulting in a significant decrease in endogenous spermidine (Spd) content in inferior grains, but a significant increase in ETH release rate. Post-flowering application of exogenous Spd increased the accumulation of sucrose and starch in the inferior grains and positively regulated the filling and grain weight of the inferior grains, whereas exogenous ETH had a negative effect. Overall, Spd may affect wheat grain weight at high planting density by promoting the synthesis of sucrose and starch in inferior grains.

Vegetation Analysis in the Archaeological Area of Pasargadae WHS (Iran) Enhancing the Naturalistic Value of the Site within the Occurring Environmental Changes

This study provides pioneering research on the vegetation of archaeological areas in Iran to enhance its naturalistic and bioindication values by selecting the Pasargadae World Heritage Site (WHS). Vegetation surveys were carried out in different homogeneous habitats, analyzing the plant communities through statistical elaboration, syntaxonomic role, mapping, and enhancement of plants with conservation interest. In an ecological approach, the study included an analysis of the recent climate changes and human interventions influencing the water resources. Results revealed seven main vegetation types reflecting ecological gradients shaped by environmental, edaphic, and anthropogenic factors. The syntaxonomic analysis showed a primary subdivision in semi-natural grasslands and synanthropic vegetation. Several key species were identified as bioindicators of multiple factors, such as: Launaea acanthodes, Stipa barbata, Alhagi maurorum, Bellevalia saviczii, Glycyrrhiza glabra, Convolvulus arvensis, and Hordeum murinum. The vegetation map showed how the hilly grassland communities hosted the highest number of species with conservation interest and their need to be better protected. Bio-climatic data, such as the construction of dams and the exploitation for irrigation purposes, pointed to the increasing xeric conditions, which make urging conservation efforts for the site’s historical and naturalistic values. The study underscores the importance of preserving places with high plant diversity for effective site management, and enhances the intricate relationship between vegetation and natural features in the occurring environmental changes.

Alleviation of heat stress by ACC Deaminase and Exopolysaccharide Producing Plant-Growth-Promoting Rhizobacteria in Solanum melongena L.

Background: The current study was carried out to assess the alternative role of high temperature tolerant plant growth promoting rhizobacteria (PGPR) in alleviation of heat stress adverse effect in eggplant.Methods: PGPR was assessed for PGP potentialities and investigated for1‐aminocyclopropane‐1‐carboxylate (ACC deaminase), and exopolysaccharide under normal and high temperature environment. The impact of PGPR application on plant physiology and biochemistry was investigated under normal and high temperature environments and plant growth regulators were evaluated using High Performance Liquid Chromatography (HPLC).Results: A significant impediment for morphological and physiological parameters of eggplant cultivars was observed during heat stress in absence of PGPR inoculation. The results showed that ACC‐deaminase produced by PGPR boosted up significantly the extracellular polymeric substances (EPS) accumulation, conversion of ACC into α‐ketobutyrate and ammonia, and reduce consequently the impact of high temperature on eggplant development.Conclusion: PGPR inoculation showed an alternative strategy to improve eggplant growth and development under high temperature condition in order to preserve agriculture sustainability and healthy crops.Keywords: ACC‐deaminase; Extracellular polymeric substances; Heat stress; PGPR; Solanum melongena

Shifts in belowground processes along a temperate forest edge

ContextForests are increasingly fragmented, and as a result most forests in the United States are within one km of an edge. Edges change environmental conditions of the forest—especially radiation, roughness, temperature, and moisture—that can have consequences for plant productivity and ecosystem functions. However, edge effects on aboveground characteristics of plants and the environment are better understood relative to plant roots and soil in the belowground environment.ObjectivesOur main objectives were to determine if soil C pools and fluxes are higher at the edge relative to other landscape positions, and to understand how specific belowground processes contribute to bulk differences in pools and fluxes.MethodsWe measured environmental conditions, live and dead fine root traits, soil chemistry, and soil respiration along a 75 m transect from interior forest to meadow in Gaithersburg, MD.ResultsWe observed differences in the soil chemical, biological and hydrological environment between the forest interior, edge and adjacent meadow. In some cases, the forest edge represented a mid-point in environmental or belowground characteristics between the forest interior and meadow (e.g., pH, C-to-N ratio [C:N], live fine root biomass, heterotrophic respiration), likely reflecting the change in litter type and quality associated with the transition from grass to woody species. In other cases, neighboring landscape positions were different from the forest edge, which was drier and had higher dead fine root biomass. Although soil C contents were not significantly different across landscape positions, there was a tendency towards higher average soil C content at the edge relative to other landscape positions, suggesting that increased C loss related to root decay and greater soil respiration at the edge relative to the forest interior may have been offset by increased C gain from high plant productivity and subsequent inputs to soil.ConclusionsThis research provides insight into how forest edge environments may differ from the interior and how concurrent processes above- and belowground may contribute to those differences.