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Concentrations of total aluminium (Al) and iron (Fe) were determined in Lake Loskop over a period of four months in 2009 in samples of phytobenthos, phytoplankton, macroinvertebrates, amphibians and fish. The highest concentrations of Al and Fe were measured in the filamentous algae Spirogyra fluviatilis (Hillse) and Spirogyra adanata (Kütz), (Al=18,997.5mgkg(-1) dry weight and Fe=22,054.2mgkg(-1) dry weight) in the riverine zone of the lake with a near-neutral water average pH of 7.3. However, a negative correlation exists between the Al and Fe concentrations measured in the filamentous algae in comparison with the corresponding concentrations of these elements in the water column of the riverine zone. The Al concentrations in the macroinvertebrate families collected ranged from 140.6 to 385.7mgkg(-1) dry weight, with the highest values measured for Al and Fe in the family Gomphidae (385.7 and 1710.0mgkg(-1) dry weight, respectively) in comparison to other macroinvertebrate families sampled. Al and Fe concentrations (2580 and 10,697mgkg(-1) dry weight) in the stomach contents of adult Oreochromis mossambicus fishes were much higher in comparison with adult Micropterus salmoides fishes (98.5 and 439.6mgkg(-1) dry weight), respectively. In all cases of dissected fish species either white or yellow body fat was observed, thus in none of the samples both type of body fats occurred simultaneously. The concentrations of total Al and Fe in the different organs of O. mossambicus were along a mean sequence of intestine>yellow body fat>brain>gills>liver>heart>white body fat, while the mean sequence of total Al and Fe in M. salmoides was: intestine>gills>liver>heart>brain>white body fat. From the levels of Al detected in the yellow body fat of the studied fish species O. mossambicus, we suggest that this phenomenon may be related to the feeding habits of this species. Furthermore, the intake of certain species of phytobenthos by O. mossambicus could have played a role in the bioaccumulation of Al in the food chain and the possible development of pansteatitis in predators at higher trophic levels., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Studies were conducted to determine the effects of a panel of seven nanomaterials (NMs), namely: α-alumina, γ-alumina, precipitated silica; silica fume, calcined silica fume, colloidal antimony pentoxide (Sb(2)O(5)), and superfine amorphous ferric oxide (Fe(2)O(3)), on sediment dwelling invertebrates Chironomus tentans under controlled laboratory conditions. Percentage survival, enzyme activities, growth development, and DNA fragmentation parameters were studied as acute, biochemical, and physiological toxicities of NMs, respectively. Quantitation of catalase and peroxidase enzyme activity demonstrated that toxicant stress of the NMs increased enzyme activity in a concentration dependent fashion across all treatments. The percentage growth length of the test specimens exposed to different NMs was significantly reduced compared to the negative control while only five concentrations were not in the toxic range, namely; Fe(2)O(3) (5 μg/kg); silica fume (5 μg/kg, 50 μg/kg); Sb(2)O(5) (5 μg/kg) and calcined silica fume (5 μg/kg). Genotoxic stress assessed by use of DNA laddering showed complementary findings to the other ecotoxicological endpoints tested in this study--the percentage survival and growth length inhibition., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Although several wheat genes differentially expressed during the Russian wheat aphid resistance response have recently been identified, their requirement for and specific role in resistance remain unclear. Progress in wheat-aphid interaction research is hampered by inadequate collections of mutant germplasm and difficulty in transforming hexaploid wheat. Virus-induced gene silencing (VIGS) technology is emerging as a viable reverse genetics approach in cereal crops. However, the potential of VIGS for determining aphid defence gene function in wheat has not been evaluated. We report on the use of recombinant barley stripe mosaic virus (BSMV) to target and silence a WRKY53 transcription factor and an inducible phenylalanine ammonia-lyase (PAL) gene, both predicted to contribute to aphid defence in a genetically resistant wheat line. After inoculating resistant wheat with the VIGS constructs, transcript abundance was reduced to levels similar to that observed in susceptible wheat. Notably, the level of PAL expression was also suppressed by the WKRY53 construct, suggesting that these genes operate in the same defence response network. Both knockdowns exhibited a susceptible phenotype upon aphid infestation, and aphids feeding on silenced plants exhibited a significant increase in fitness compared to aphids feeding on control plants. Altered plant phenotype and changes in aphid behaviour after silencing imply that WKRY53 and PAL play key roles in generating a successful resistance response. This study is the first report on the successful use of VIGS to investigate genes involved in wheat-insect interactions., (© 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology and Blackwell Publishing Ltd.)

The occurrence of a sunflower oil spill in 2007 in the Con Joubert Bird Sanctuary freshwater wetland, South Africa, inhibited the growth of sensitive phytoplankton species and promoted that of tolerant species. The algal divisions Chlorophyta and Euglenophyta were well represented in the sunflower oil contaminated water, especially the species Euglena sociabilis, Phacus pleuronectes and Chlamydomonas africana. Young and mature resting zygotes of Chlamydomonas africana were recorded in high abundance at all the sunflower oil contaminated sampling sites. The phytobenthos diversity and abundance were significantly suppressed and negatively associated with low Dissolved Oxygen concentrations and the negative redox potential of the bottom sediment. At the intracellular level, phytoplankton chlorophyll a and b concentrations as physiological variables were more sensitive indicators of the adverse effects of sunflower oil than the 72 h Selenastrum capricornutum algal bioassay conducted.

Increasing uses of engineered nanoparticles (ENPs) in commercial products and industrial applications has eventually resulted to their releases into atmospheric, terrestrial, and aquatic environments. However, knowledge gaps in ENPs toxicity, fate, and behaviour currently limit our ability to quantify risk assessment of materials with nanoscale dimensions, and therefore, the extent of the resultant environmental impacts remains unknown. In the present study, we evaluated the effects of γ-alumina, α-alumina, modified TiO(2) (M-TiO(2)), and commercial TiO(2) (C-TiO(2)) ENPs on the survival, behaviour, and early life stages of the freshwater snail Physa acuta (Draparnaud). The toxicity evaluation was carried out after spiking commercial sand with ENPs concentrations of 0.005, 0.05, or 0.5 gk g(-1). Our findings suggest that increases of γ-alumina and α-alumina concentrations at sub-lethal level concentrations caused significant reduction in the embryo growth rate and embryo hatchability. In addition, these ENPs induced observable developmental deformities of the embryos. In addition, toxicity evaluations using acute 96-h and chronic 28-d tests showed exposure duration may be a significant factor in ENPs-induced toxicity. Therefore, long-term exposure of aquatic organisms to ENPs - potentially can alter certain ecological populations at different trophic levels - and may compromise the entire aquatic ecological functionality. The percentage hatchlings in test chambers containing 0.5 gk g(-1) γ-alumina and α-alumina concentration was 50% less to those observed in the controls. Our results suggest the embryonic growth and hatchability tests are useful endpoints in chronic sediment toxicity tests for determining the toxic thresholds of ENPs in sediment environment. Although no snail mortalities were observed during the static 96-h test containing sediment spiked with different concentrations of M-TiO(2), C-TiO(2), γ-alumina and α-alumina - the antioxidant enzymatic assay results indicated a significant change in antioxidant levels which altered peroxidation at 0.05 or 0.5 gk g(-1)concentrations for both γ-alumina and α-alumina., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Diuraphis noxia (Kurdjumov)(Russian wheat aphid) has severe economic impacts on wheat and barley production in the United States. The interaction between the Russian wheat aphid and its cereal hosts is poorly understood. However, the recent appearance of new biotypes in the United States showed that specific interactions exist between wheat resistance loci and Russian wheat aphid biotypes. At present, Dn7 is the only known gene in hexaploid wheat that confers resistance against all U.S. Russian wheat aphid biotypes. This study was conducted to investigate the molecular mechanism of Dn7-mediated resistance against two U.S. Russian wheat aphid biotypes (Russian wheat aphid 1 and Russian wheat aphid 2). Using GeneChip Wheat Genome Arrays, we compared transcript profiles of resistant and susceptible lines infested with either Russian wheat aphid 1 or Russian wheat aphid 2 using two time intervals (5 and 48 h after infestation). Russian wheat aphid feeding on hexaploid wheat led to the induction of groups of genes functioning in oxidative and general stress, photosynthesis, cell respiration and energy production, signal transduction, calcium-dependent signaling, pathogenesis related (PR) responses, and defense compound synthesis. The number of differentially expressed genes was higher in plants infested with Russian wheat aphid 1 compared with those infested with Russian wheat aphid 2. Although most genes involved in basic cellular functions were shared, unique genes were also obtained. This finding may indicate subtle differences in genes induced in response to different virulence proteins.

Symbiosis allows an insect access to imbalanced food sources on which other organisms cannot survive. A bacterial endosymbiont, Buchnera aphidicola, gives aphids the ability to feed on phloem depleted of certain essential amino acids by producing those required. Pseudogenes and lower plasmid copy numbers of essential amino acid genes in B. aphidicola, endosymbiont of the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), suggest that this symbiotic relationship is degenerating. The complete endosymbiont assemblages, copy numbers of plasmids (important in essential amino acid production), and sequence variation in B. aphidicola, from 10 Russian wheat aphid biotypes, were investigated. B. aphidicola was found to be monosymbiotic in the Russian wheat aphid biotypes and other Diuraphis species examined. An insert, occurring in an inverted repeat region on the leucine plasmid, was the only variation found in the approximately 10-kb B. aphidicola sequence analyzed from each Russian wheat aphid biotype. This inverted repeat was shown previously to be conserved within the family Aphididae. The insert occurred in B. aphidicola sequences isolated from four Russian wheat aphid biotypes. Copy numbers of the leucine plasmid differ between the South African and U.S. biotypes and were similar to previously reported values for biotypes from the same geographic regions. These results suggest that B. aphidicola may still contribute to Russian wheat aphid fitness when the aphid feeds on a variety of hosts.

The relationships between water quality and the phytoplankton community within Lake Loskop were studied during the late summer and autumn of 2008 to evaluate the impacts of acid mine drainage and high nutrient concentrations. The higher concentrations of metal ions and sulphate had adverse effects on certain phytoplankton species in the inflowing riverine zone of Lake Loskop, in comparison to the reference site in the lacustrine zone of the lake, which was dominated by the larger and slower growing late summer species of Coelastrum reticulum Nägeli, Straurastrum anatinum Meyen ex Ralfs and Ceratium hirundinella Müller. The high nutrient concentrations (nitrogen: 17 mg l(-1) and orthophosphate: 0.7 mg l(-1)) during the mid-summer peak of the rainy season were associated with the development of a bloom of the cyanobacterium Microcystis. Water quality data associated with the development of the Microcystis bloom suggest that the aquatic system of Lake Loskop has now entered an alternate, hypertrophic regime. This change overshadowed the adverse effects of high concentrations of heavy metal ions and low pH. Throughout this study, the reference site in the lacustrine zone of Lake Loskop had lower concentrations of metal ions and sulphate, and higher pH values. The response of phytoplankton bioassays on integrated water samples from the different sampling sites did provide potential answers to the reasons for the absence of the algal group Chlorophyceae in the phytoplankton community structure in the riverine zone of the lake., ((c) 2009 Elsevier Inc. All rights reserved.)

For sustainable solutions to the problem of insect infestation, the study of molecular plant-insect interactions is integral to resistance breeding strategies. This also holds true in the case of wheat (Triticum aestivum), where the Russian wheat aphid (Diuraphis noxia, Kurdjumov, RWA) is responsible for significant crop losses in most major wheat producing countries around the world. Our study is focused on gaining a greater understanding of the resistance mechanisms activated by the RWA resistance gene Dn7 by comparing responses following infestation with three different aphid biotypes (RWA-SA, RWA-US1 and RWA-US2). This consisted of analyzing the resistant wheat line 94M370 (containing Dn7) and its susceptible counterpart (Gamtoos) on a transcriptional level with complementary DNA-amplified fragment length polymorphisms (cDNA-AFLPs) using 17 primer combinations, as well as quantitative reverse transcription polymerase chain reaction (qRT-PCR) of 10 differentially expressed transcripts. The results of this expression profile analysis suggest that Dn7 activates similar responses against the two US aphid biotypes, which differ noticeably from the response following infestation with a South African aphid biotype. This is consistent with recent research showing limited molecular variations between the two US aphid biotypes (approximately 0.12%), compared with a distinctly different South African biotype. We therefore conclude that Dn7 recognizes and interacts in a highly specific manner with different aphid's putative eliciting agents, which in turn activates specific defense pathways unique to that interaction.

The eutrophic process potentially caused by a high urine and faecal load resulting from an unusually high hippopotamus (Hippopotamus amphibious) density in the Nhlanganzwane Dam, Kruger National Park, South Africa, triggered a chain of events characterised by an increase in the growth of primary producers (Microcystis aeruginosa). This increase in M. aeruginosa biomass was followed by bio-intoxication incidents in wild animals. In this study, we determine if a M. aeruginosa bloom with a total microcystin level of 23,718microgl(-1) have been responsible for mortalities of megaherbivores in the Nhlanganzwane Dam. We further use microcystin molecular markers derived from the mcy gene cluster to identify potentially toxigenic environmental Microcystis strains in the dam during the occurrence of animal intoxications. The estimated total microcystin-LR daily intake by an adult male white rhinoceros (Ceratotherium simum) from cyanobacterial-contaminated water of the dam during the toxic event was an order of magnitude higher (754.29microgkg(-1)bw) in comparison with the lowest observed adverse effecting level (LOAEL) value measured for pigs in a previous study by other authors. In this study the presence of toxic cyanobacterial strains was confirmed with the use of molecular markers that detected the presence of the mcy gene cluster responsible for the production of toxin by M. aeruginosa.

Breeding for malting quality is an important goal of malting barley breeding programs. Malting quality is a complex phenotype that combines a large number of interrelated components, each of which shows complex inheritance. Currently, only a few genes involved in determining malting quality have been characterized. We combined transcript profiling with phenotypic correlations to identify candidate genes for malting quality. The Barley1 GeneChip array containing 22,792 probe sets was used to conduct transcript profiling of genes expressed in several different stages of malting of four malting cultivars. Genes that were differentially expressed in comparisons between different malting stages relative to ungerminated seed, as well as in comparisons between malting cultivars in the same malting stage were identified. Correlation analysis of 723 differentially expressed genes with malting quality phenotypes showed that 11-102 of these genes correlated with six malting quality phenotypes. Genes involved in carbohydrate metabolism were among the positively correlated genes. Genes for protein and lipid metabolism, cell wall organization and biogenesis, and genes involved in stress and defense response also correlated with malting quality phenotypes. Expressed sequence tags (ESTs) were generated from a 'malting-gene enriched' cDNA library made by suppression subtractive hybridization between malted and ungerminated seeds of 'Morex'. Eleven percent of the ESTs had no significant homology with sequences in the databases, suggesting that there may be other malting-related genes not represented in the barley gene chip array. The results provide candidate genes for malting quality phenotypes that need to be functionally validated.

The biological interactions and the physical and chemical properties of the littoral zone of Lake Krugersdrift were studied for a 4-month period when a dense, toxic cyanobacterial bloom dominated by Microcystis aeruginosa was present in the main lake basin. The presence of a toxic strain of M. aeruginosa was confirmed through the use of ELISA and molecular markers that detect the presence of the mcyB and mcyD genes of the mcy gene cluster that synthesizes microcystin. An increase in Microcystis toxicity at sites dominated by the cyanobacterial scum was accompanied by an increase in total abundance of the macroinvertebrate families Hirudinae, Chironomidae, and Tubificidae. Sites located away from the cyanobacterial scum had a lower abundance but a higher diversity of macroinvertebrates. The water quality under the Microcystis scum was characterized by low pH values, low concentrations of dissolved oxygen, and lower total alkalinity values. The periphytic alga Ulothrix zonata was absent in areas dominated by the cyanobacterial scum, possibly as a result of overshadowing by the scum or direct toxic allelopathic effects on growth and photosynthesis. The diatom Diatoma vulgare dominated the benthic algal flora beneath the cyanobacterial scum.

Macroinvertebrate communities in Rietvlei nature reserve wetland area and their relationship with water quality were studied with the aim to evaluate their use as potential indicators of pollution. Sampling locations were selected to include outlets from sewage effluent, agricultural and informal residential runoff. A large increase in nutrient concentrations was observed downstream from discharged treated sewage with an associated decrease in species richness. Bioassays performed included: Daphnia magna, Hydra attenuate, Lactuca sativa, Allium cepa and Pyxicephalus adspersus. The highest percentage of lethality response to a screen (100% concentration) of sampled wetland water by test specimens were observed at the point source input of the Hartbeespoort treated sewage plant. Data generated from the AUSRIVAS method and multitrophic level bioassays revealed the deterioration of the wetland possibly due to factors such as increasing urbanization, industrialization, agriculture runoff and rapid human settlement in the Hennops River catchment area and its principal tributaries.

It is hypothesized that the interaction between aphids and plants follows a gene-for-gene model. The recent appearance of several new Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Homoptera: Aphididae), biotypes in the United States and the differential response of wheat, Triticum aestivum L., genotypes containing different resistance genes also suggest a gene-for-gene interaction. However, aphid elicitors remain unknown. This study was conducted to identify fractionated Russian wheat aphid extracts capable of eliciting differential responses between resistant and susceptible wheat genotypes. We extracted whole soluble compounds and separated proteins and metabolites from two Russian wheat aphid biotypes (1 and 2), injected these extracts into seedlings of susceptible wheat Gamtoos (dn7) and resistant 94M370 (Dn7), and determined phenotypic and biochemical plant responses. Injections of whole extract or protein extract from both biotypes induced the typical susceptible symptom, leaf rolling, in the susceptible cultivar, but not in the resistant cultivar. Furthermore, multiple injections with protein extract from biotype 2 induced the development of chlorosis, head trapping, and stunting in susceptible wheat. Injection with metabolite, buffer, or chitin, did not produce any susceptible symptoms in either genotype. The protein extract from the two biotypes also induced significantly higher activities of three defense-response enzymes (catalase, peroxidase, and beta-glucanase) in 94M370 than in Gamtoos. These results indicate that a protein elicitor from the Russian wheat aphid is recognized by a plant receptor, and the recognition is mediated by the Dn7-gene product. The increased activities of defense-response enzymes in resistant plants after injection with the protein fraction suggest that defense response genes are induced after recognition of aphid elicitors by the plant.

Knowledge of genetic diversity (GD) and relationships among maize inbred lines is indispensable in a breeding program. Our objectives were to (1) investigate the level of genetic diversity among maize inbred lines and (2) assess their genetic structures by applying simple sequence repeat (SSR) markers. Fifty-six highland and mid-altitude maize inbred lines obtained from CIMMYT programs in Ethiopia and Zimbabwe were genotyped using 27 SSR loci. All of the genotypes studied could unequivocally be distinguished with the combination of the SSRs used. In total, 104 SSR alleles were identified, with a mean of 3.85 alleles per locus. The average polymorphism information content (PIC) was 0.58. GD expressed as Euclidean distance, varied from 0.28 to 0.73 with an average of 0.59. Cluster analysis using unweighted pair group method with arithmetic average (UPGMA) suggested five groups among the inbred lines. Most of the inbred lines adapted to the highlands and the mid-altitudes were positioned in different clusters with a few discrepancies. The pattern of groupings of the inbred lines was mostly consistent with available pedigree information. The variability detected using SSR markers could potentially contribute towards effective utilization of the inbred lines for the exploitation of heterosis and formation of genetically diverse source populations in Ethiopian maize improvement programs.

Diuraphis noxia (Russian wheat aphid, RWA) is a major pest on wheat in South Africa and most other wheat growing countries. Being a probing-sucking insect, RWAs insert their stylets into the phloem sieve elements and feed on the phloem sap. This feeding causes necrotic lesions in resistant varieties, or decoloration of leaves and death in susceptible varieties. In an effort to broaden our understanding on the response of the plant to RWA feeding, we synthesized and analyzed expressed sequence tags (ESTs) from suppression subtractive hybridization (SSH) libraries. These libraries were constructed using near isogenic wheat lines susceptible "Tugela" and resistant "TugelaDN" (Dn1) to RWA, as well as accession lines PI137739 (Dn1) and PI294994 (Dn5). Analysis of 200 ESTs from the libraries revealed the involvement of transcripts encoding genes involved in cell maintenance, growth and regulation, plant defense and signaling, photosynthesis and energy production, and of unknown function. A selection of these ESTs, in combination with clones obtained from other sources, were used on a custom array to study the expression profiles of 256 candidate wheat sequences putatively involved in plant defense against RWA. The selected sequences included wheat genomic clones with putative nucleotide binding site (NBS) motifs, rapid amplification of cDNA ends PCR (RACE-PCR), and cDNA clones from RWA induced libraries. Genomic banana and flax clones that were obtained using representative difference analysis (RDA), and suspected to be involved in abiotic stress responses, were also spotted onto the microarray slides. The spotted custom arrays were then hybridized against cDNA isolated from a resistant cultivar "TugelaDN" on 0, 2, 5, and 8 days after infestation, post-labeled with Cy3- or Cy5-fluorescent dyes. The subsequent expression profiling using DNA microarray, RT-PCR, and Northern Blot analysis identified 29 transcripts associated with the feeding response. These transcripts encoded proteins functioning in direct defense and signaling, oxidative burst, cell wall degradation, cell maintenance, photosynthesis, and energy production. Results indicate that plants co-ordinately regulate gene expression when attacked by RWA. It is hypothesized that the NBS-LRR proteins are important in receptor recognition and signaling, which enable the plant to overcome the stresses inflicted by RWA feeding. It is further suggested that the ability to maintain photosynthetic function with resultant energy production is one of the determining factors ensuring the survival of the resistant varieties when coping with the RWA feeding.

This survey provides information on sediment toxicity and structural characteristics of the macroinvertebrates and benthic phytoplankton at 10 locations in the Cache la Poudre River after long-term exposure to coal tar residue. The application of the Australian river bioassessment system (AUSRIVAS) as well as a biotest battery was used to evaluate the river 'health' condition. Coal tar is a dense nonaqueous-phase liquid of significant environmental concern due to its toxicity and persistence in the subsurface. Organisms like Selenastrum capricornutum, Daphnia magna and Chironomus tentans, representing different complexities in the biosphere, were selected as test systems for ecotoxicological studies. The results obtained in this study indicate that a biotest battery, macroinvertebrate and benthic phytoplankton communities are in principle suitable biological tools for evaluation of toxic oil and coal-derived substances in long-term contaminated river sediment.

Cryphonectria cubensis causes a serious Eucalyptus canker disease. Fungal cell wall degrading enzymes (CWDEs) are important during the early stages of interaction of the fungus with Eucalyptus. To improve our understanding of the molecular regulation of the interaction of Eucalyptus and C. cubensis, the relevant genes involved in this interaction should be identified, cloned and studied. The aim of this study was, therefore, to clone the endopolygalacturonase (endoPG) gene of C. cubensis. C. cubensis was grown on a medium supplemented with Eucalyptus cell wall extracts. Degenerate primers were designed to amplify part of the endoPG gene from C. cubensis genomic DNA. The resulting sequence was used to design specific primers for use in inverse PCR to amplify the entire endoPG gene of C. cubensis (ccen-1). The endoPG sequence of C. cubensis has 93% amino acid sequence similarity to that of the chestnut blight pathogen, Cryphonectria parasitica.

The fungus Fusarium circinatum causes pitch canker disease on mature pine trees and root rot and damping-off of pine seedlings. Endopolygalacturonases (endoPGs) play a major role during penetration of plants by fungi. Digestion of the pectic polysaccharides in the plant primary cell walls is one of the earliest functions of endoPGs during infection. The research objective was to clone and characterize the gene encoding endopolygalacturonase in F. circinatum. A 970-bp DNA fragment was cloned by using degenerate PCR amplification from F. circinatum DNA. Sequence data for this fragment were used to design specific primers for use in genome walking to amplify and sequence the remaining portion of the F. circinatum endoPG gene (Fcpg). The amino acid sequence predicted from this gene showed 90% and 87% similarity to Fusarium oxysporum and Fusarium moniliforme endoPGs, respectively.

During germination of Citrullus lanatus, pyrophosphate-dependent phosphofructokinase (PFP) activity is induced. The peak of PFP activity coincides with the maximum gluconeogenic flux and high fructose-2,6-bisphosphate (Fru-2,6-P2) concentrations. Determination of cytosolic fructose-1,6 bisphosphatase (FBPase) activity in crude extracts is unreliable because of the high PFP activity. The FBPase activity, after correction for the contaminating PFP, is only one-third of the PFP activity. Purified cytosolic FBPase is inhibited by Fru-2,6-P2. The low cytosolic FBPase activity and high Fru-2,6-P2 most probably result in inadequate in vivo activity to catalyze the observed gluconeogenic flux. The total PFP activity is sufficient to catalyze the required carbon flux.

During germination and seedling establishment, the total pyrophosphate-dependent phosphofructokinase (PFP) activity in the cotyledons increases. Two types of subunits with molecular weights of 68 (alpha-subunit) and 65 (beta-subunit) kilodaltons are present. The increase in activity coincides with an approximately 10-fold increase in beta-subunit and twofold increase in alpha-subunit content. Different isoforms of PFP are present at all stages of incubation, but the ratio between the isoforms significantly changes. A linear relationship exists between the ratio of the two PFP subunits and the ratio of the two isoforms of the enzyme. The more anionic (peak 2) isoform of the enzyme apparently is favored by a high ratio of total beta-subunit to alpha-subunit content. The beta- to alpha-subunit ratio of the peak 2 isoform is also approximately fivefold higher than that of the peak 1 (less anionic) isoform. It is evident that the two subunits are not coordinately expressed and the level of expression of each subunit appears to be the primary factor determining the molecular form in which the enzyme is present. In some tissues, only the 65 kilodalton polypeptide is expressed in large amounts. The peak 1 isoform has a higher affinity for pyrophosphate than the peak 2 isoform, while the affinity for fructose-6-phosphate is similar. Both molecular forms are activated by fructose-2,6-bisphosphate.

Fritillaria cirrhosa is a remarkably representative endangered species on the plateau, and its phenotype has undergone dramatic alterations due to global climate change and habitat destruction. However, the mechanism behind the phenotypic change associated with color variation has not been characterized, and subsequent physiological responses are still unknown. We investigated different phenotypes of cultivated F. cirrhosa and conducted a comprehensive transcriptomic analysis. Their agronomic traits, photosynthetic parameters, and the content of pharmaceutical ingredients were also compared. In the transcriptomic profiling, the purple phenotype had 754 up-regulated and 980 down-regulated genes compared with the green F. cirrhosa, in which a total of 37 significant differential expression genes (DEGs) regulated the anthocyanin biosynthesis by coding 6 vital enzymes (C4H, F3′H, ANS, DFR, DFT, and BA1). These DEGs were key genes responsible for the form of the purple phenotype of F. cirrhosa. Moreover, 10 DEGs were observed to be related to biotic and abiotic stress responses, such as regulation of defense response to bacterium and UV regulation in the actual unshaded field environment. The results of agronomic traits indicated that the purple phenotype exhibited a multitude of merits in plant height and stem diameter (p < 0.05), and produced more high-quality fruit and seeds, which demonstrated that the purple phenotype has high regeneration ability and potential resistance to cultivation conditions. Importantly, the content of total alkaloids as bioactive ingredients in medicinal bulbs of purple F. cirrhosa was significantly higher than that in the green phenotype by 57.14%. Overall, the present study not only reveals the potential mechanisms of phenotypic variation in F. cirrhosa but also contributes to a better understand adaptation of highland species related to ecological changes, as well as paves the way for the further breeding and large-scale cultivation of F. cirrhosa. [ABSTRACT FROM AUTHOR]

Maize is an important crop in many parts of the tropical environment providing energy source for poultry and staple food supply for human as well as for industrial uses because of its diverse utilization potential. Nigeria is characterized with diverse accessions such as land, cultivars, and farmers' selected lines from many years of cropping maize for improved yield and adaptation through informal breeding programmes. The objectives of this study therefore were to evaluate white and yellow maize accessions for yield performance, disease reactions and agronomic attributes, and to further characterize them for use in planned maize breeding programmes. One hundred and sixty-five maize accessions (85 white) and (80 yellow) were used for performance evaluation and reactions to prevailing diseases of hot tropical environment, under natural field infection. The results from analysis of variance of the white and yellow maize accessions showed significant differences for plant height (3144.75 cm and 1901.54 cm), ear height (1462.98 cm and 982.76 cm), ear harvest (12.64 and 8.74), husk cover (0.83 and 0.67) and grain yield (4743.49 kg/ha and 3851.67 kg/ha) and disease syndrome ratings. This study revealed the variability in agronomic traits which will in no doubt expand the gene pool of the Institute of Agricultural Research and Training of Obafemi Awolowo University for breeders developing early, medium and late maturing white and yellow maize populations for improved agronomic potential, yield, disease resistance and adaptation to hot humid ecologies of the tropical ecosystems. [ABSTRACT FROM AUTHOR]

Preharvest sprouting (PHS) is an undesirable trait that decreases yield and quality in rice production. Understanding the genes and regulatory mechanisms underlying PHS is of great significance for breeding PHS-resistant rice. In this study, we identified a mutant, preharvest sprouting 39 (phs39), that exhibited an obvious PHS phenotype in the field. MutMap+ analysis and transgenic experiments demonstrated that OsAAH, which encodes allantoate amidohydrolase, is the causal gene of phs39 and is essential for PHS resistance. OsAAH was highly expressed in roots and leaves at the heading stage and gradually increased and then weakly declined in the seed developmental stage. OsAAH protein was localized to the endoplasmic reticulum, with a function of hydrolyzing allantoate in vitro. Disruption of OsAAH increased the levels of ureides (allantoate and allantoin) and activated the tricarboxylic acid (TCA) cycle, and thus increased energy levels in developing seeds. Additionally, the disruption of OsAAH significantly increased asparagine, arginine, and lysine levels, decreased tryptophan levels, and decreased levels of indole-3-acetic acid (IAA) and abscisic acid (ABA). Our findings revealed that the OsAAH of ureide catabolism is involved in the regulation of rice PHS via energy and hormone metabolisms, which will help to facilitate the breeding of rice PHS-resistant varieties. [ABSTRACT FROM AUTHOR]

Schmallenberg virus (SBV) is an arthropod-borne virus that emerged recently in northwestern Europe in 2011 that affects domestic and wild ruminants and induces abortion, stillbirth, and newborns with congenital anomalies. Since its discovery, SBV has spread very rapidly to too many countries in the world. The overall serological investigation of SBV is needed to improve modeling predictions and assess the overall impact on ruminant animals, which helps to design interventions for control and prevention strategies. Thus, this study aimed to estimate the overall serological assay of SBV in both domestic and wild ruminants around the world. This systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. International databases were employed To search for relevant articles. The pooled prevalence with a 95% confidence interval was calculated with a random effects model. The Cochran's Q test, t2, and I2 were used to assess the sources of heterogeneity. In the current meta-analysis, a total of 41 articles were included. The overall pooled proportion of SBV in domestic and wild ruminants was 49 and 26%, respectively. Substantial heterogeneity was observed in studies on domestic ruminants (I2 = 99.7%; p < 0.01) and studies on wild ruminants (I2 = 97.9%; p < 0.01). The pooled prevalence of SBV was significantly associated with publication time, detection techniques, and species of animals. According to the subgroup analysis, the highest pooled prevalence of SBV was reported in cattle (59%), followed by sheep (37%) and goat (18%). In addition to the subgroup analysis based on publication year, the pooled prevalence of SBV infection has become endemic since 2013 (49%) among domestic animals in the world. Of the diagnostic tests used, the highest anti-SBV antibodies (66%) were detected by a virus neutralization test. In this metaanalysis, the major wild animals that were infected by SBV were red deer, roe deer, fallow deer, mouflon, and wild boar. The highest sub-pooled prevalence of SBV was found in roe deer (46%), followed by fallow deer (30%), red deer (27%), mouflon (22%), and wild boar (11%). In general, the prevalence of SBV was high in cattle among domestic ruminants and in roe deer among wild animals. According to the current information provided by this meta-analysis, evidencebased risk management measures should be established to restrict SBV spread in both domestic and wild ruminants. [ABSTRACT FROM AUTHOR]

Background: Carrot is an important vegetable crop grown worldwide. The major economic problem in carrot cultivation is yellow disease caused by Bactericera trigonica, which induces biotic stress and has the greatest impact on crop productivity. Comprehensive studies on the mechanism of carrot defense response to biotic stress caused by B. trigonica infestation have yet to be conducted. Methods: The changes in photosynthetic pigments, proline, TPC, H2O2 and MDA content, DPPH radical scavenging ability, and antioxidant enzyme activity of SOD, CAT, and POX in carrot leaves in response to insect sex (female and male), rapid response (during the first six hours), and long-term response to B. trigonica infestation were evaluated. Results: The results of our study strongly suggest that B. trigonica infestation causes significant changes in primary and secondary metabolism and oxidative status of carrot leaves. Photosynthetic pigment content, TPC, and DPPH and CAT activities were significantly reduced in carrot leaves in response to insect infestation. On the other hand, proline, H2O2 content, and the activity of the antioxidant enzymes superoxide dismutase and peroxidase were increased in carrot leaves after B. trigonica infestation. The results indicate that B. trigonica attenuates and delays the oxidative stress responses of carrot, allowing long-term feeding without visible changes in the plant. Carrot responded to long-term B. trigonica infestation with an increase in SOD and POX activity, suggesting that these enzymes may play a key role in plant defense mechanisms. Conclusions: This is the first comprehensive study strongly suggesting that B. trigonica infestation causes significant changes in primary and secondary metabolism and an attenuated ROS defense response in carrot leaves that enables long-term insect feeding. The information provides new insights into the mechanisms of carrot protection against B. trigonica infestation. [ABSTRACT FROM AUTHOR]

After initiation of radicle elongation, the pyrophosphate:d-fructose-6-phosphate 1-phosphotransferase (PFP) activity sharply increases in the cotyledons of Citrullus lanatus. Removal of the radicle early during incubation prevents the increase in PFP activity in the cotyledons evident in the control. Removal of the radicle at any stage after germination results in a decrease in PFP activity in the cotyledons. Application of kinetin (0.5 micromolar) or 2-chlorophosphonic acid (0.1 micromolar) to isolated cotyledons replaces the effect of the radicle. Gibberellic acid (0.09 micromolar GA(3)) also partially mimics the presence of the radicle. Anaerobic conditions, as well as cycloheximide application (0.18 micromolar) to intact embryos or to kinetin and ethrel treated isolated cotyledons prevent the increase in PFP activity evident in the control.

Background: Piercing-sucking insects secrete diverse repertoires of effectors into their hosts to weaken host defenses and promote infestation. The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most destructive insect pest in citrus orchards because of its role as a vector for the huanglongbing pathogen, Candidatus Liberibacter asiaticus (CLas). However, specific effector proteins and their functions in D. citri remain unclear., Results: We demonstrate that DcE1, a salivary protein gene from D. citri, is predominantly expressed in the salivary gland tissues and is delivered into host plants during feeding. Transient expression in tobacco leaves revealed that DcE1 was subcellularly localized in the cytoplasm and plasma membrane, where it inhibited BAX- and INF1-induced cell death, suppressed callose deposition, and activated the salicylic acid pathway by upregulating the expression of endo-β-1,3-glucanase NtBGL2 and regulatory protein NtNPR1. Further, DcE1 knockdown by double-stranded RNA (dsRNA) injection decreased the survival rates of D. citri and interrupted D. citri phloem-feeding on host plants., Conclusion: These results indicate that DcE1 is a novel effector that promotes plant susceptibility and enables D. citri feeding. These findings enhance our understanding of D. citri-plant interactions and offer a potential new target gene for the development of citrus protection strategies. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Lake Mustijärv was reconstructed by sediment removal following an almost complete siltation. Here we evaluate challenges and opportunities for the management of the lake. We focused on the stream discharging to the lake (i.e., external loading), sediment retention in accumulation basins (i.e., internal processes) as well as the ecosystem-level response to stressors based on biological variables (phyto- and zooplankton, macrophytes, fishes and zoobenthos). Urban and agricultural inputs elevated ammonium and total phosphorus concentrations in the lake, challenging lake reconstruction efforts. Sediment transport highly increased the risk of faster filling of the lake, associated with upstream streambed excavation. Sediments trapped at the accumulation basins release nutrients that enhance eutrophication. We, however, observed a rapid recovery in fish, macrophytes, and zoobenthos, despite the significant disturbances. Lake Mustijärv is in eutrophic condition, reflected by phytoplankton (Pseudanabaena, Closteriopsis dominance) and zooplankton (Keratella, Polyarthra dominance) composition. To improve lake water quality will require controlling external nutrient inputs, underlining the importance of better coordinated activities between the local (lake restoration) and regional (catchment use) scales. [ABSTRACT FROM AUTHOR]

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This review aims to perform an updated bibliographical survey on the cultivation of microalgae in domestic wastewater with a focus on biotechnological aspects. It was verified that the largest number of researches developed was about cultures in microalgae-bacteria consortium and mixed cultures of microalgae, followed by researches referring to the species Chlorella vulgaris and to the family Scenedesmaceae. According to published studies, these microorganisms are efficient in the biological treatment of domestic wastewater, as well as in the production of high value-added biomass, as they are capable of biosorbing the organic and inorganic compounds present in the culture medium, thus generating cells with high levels of lipids, proteins, and carbohydrates. These compounds are of great importance for different industry sectors, such as pharmaceuticals, food, and also for agriculture and aquaculture. In addition, biomolecules produced by microalgae can be extracted for several biotechnological applications; however, most studies focus on the production of biofuels, with biodiesel being the main one. There are also other emerging applications that still require more in-depth research, such as the use of biomass as a biofertilizer and biostimulant in the production of bioplastic. Therefore, it is concluded that the cultivation of microalgae in domestic wastewater is a sustainable way to promote effluent bioremediation and produce valuable biomass for the biobased industry, contributing to the development of technology for the green economy. [ABSTRACT FROM AUTHOR]

Withania somnifera (L.) Dunal, popularly known as Ashwagandha or Indian ginseng, is well acclaimed for its health-enhancing effects, including its potent immunomodulatory, anti-inflammatory, neuroprotective, and anti-tumorigenic properties. The prime biological effectors of these attributes are a diverse group of ergostane-based steroidal lactones termed withanolides. Withanones and withanosides are distributed differentially across the plant body, whereas withanolides and withanones are known to be more abundant in leaves, while withanosides are found exclusively in the roots of the plants. Standardized W. somnifera extract is Generally Recognized as Safe (GRAS)-affirmed, however, moderate to severe toxic manifestations may occur at high dosages. Withaferin A, which also happens to be the primary bioactive ingredient for the effectiveness of this plant. There have been contrasting reports regarding the distribution of withaferin A in W. somnifera. While most reports state that the roots of the plant have the highest concentrations of this phytochemical, several others have indicated that leaves can accumulate withaferin A in proportionately higher amounts. A comprehensive survey of the available reports suggests that the biological effects of Ashwagandha are grossly synergistic in nature, with many withanolides together mediating the desired physiological effect. In addition, an assorted formulation of withanolides can also neutralize the toxic effects (if any) associated with withaferin A. This mini-review presents a fresh take on the recent developments regarding the safety and toxicity of the plant, along with a critical assessment of the use of roots against leaves as well as whole plants to develop therapeutic formulations. Going by the currently available scientific evidence, it is safe to infer that the use of whole plant formulations instead of exclusively root or leaf recipes may present the best possible option for further exploration of therapeutic benefits from this novel medicinal plant. Therapeutic potential of withanolides owes to the presence of α,β unsaturated ketone which binds to amines, alcohols, and esters and 5β, 6β epoxy group which react with side chain thiols of proteins. At concentrations above NOAEL (no observed adverse effect level), the same mechanisms contribute towards toxicity of the molecule. Although withanosides are found exclusively in roots, whole plants have higher contents of withanones and withanolides. Whole plant-based formulations have other metabolites which can nullify the toxicity associated with roots. Extracts made from whole plants, therefore can holistically impart all therapeutic benefits as well as mitigate toxicity. [ABSTRACT FROM AUTHOR]

BACKGROUND: The English grain aphid, Sitobion avenae (Fabricius), is a devastating pest impacts yield and quality in wheat (Triticum aestivum L.). Breeding resistant wheat varieties and detecting resistance genes are important strategies to control aphid. RESULTS: In this study, we evaluated the number of aphids per spike, the rate of thousand kernel weight decrease and aphid index based on three classic resistance mechanisms (antibiosis, tolerance and antixenosis), and detected SNPs/QTLs for resistance to S. avenae in a natural population of 163 varieties with 20 689 high‐quality single‐nucleotide polymorphism (SNP) markers and recombinant inbred line (RIL) population of 164 lines with 3627 diversity arrays technology (DArT) markers. Results showed that 83 loci significantly associated with S. avenae antibiosis and 182 loci significantly associated with S. avenae tolerance were detected by genome‐wide association study (GWAS), explaining 6.47–15.82% and 8.36–35.61% of the phenotypic variances, respectively. The wsnp_Ku_c4568_8243646 detected in two periods was localized at 34.52 Mb on chromosome 3AS. Then, we confirmed a stable QSa.haust‐3A.2 explained 11.19–20.10% of the phenotypic variances in two periods with S. avenae antixenosis in the physical interval of 37.49–37.50 Mb on chromosome 3A in the RIL population. Therefore, a narrow region in the physical interval of 34.52–37.50 Mb on chromosome 3AS was named as qSa‐3A, which was a new locus between wsnp_Ku_c4568_8243646 and QSa.haust‐3A.2 associated with S. avenae resistance. CONCLUSION: We found qSa‐3A was a new locus associated with S. avenae resistance. The results could be applied in gene cloning and genetic improvement of S. avenae resistance in wheat. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

It is undeniable that removal efficiency is the main factor in coagulation-flocculation (C-F) process for wastewater treatment. However, as far as environmental safety is concerned, the ecotoxicological aspect of the C-F process needs to be examined further. In this study, a systematic review was performed based on publications related to the toxicity research in C-F technology for wastewater treatment. Through a series of screening steps, available toxicity studies were categorized into four themes, namely acute toxicity, phytotoxicity, cytotoxicity, and genotoxicity, which comprised 48 articles. A compilation of the methodologies executed for each theme was also outlined. The findings show that conventional metallic coagulants (e.g., alum, iron chloride, and iron sulfate) were less toxic when tested on test species such as Daphnia magna (water flea), Lattuca sativa (lettuce), and animal cells compared to synthetic polymers. Natural coagulants such as chitosan or Moringa oleifera were less toxic compared to metallic coagulants; however, inconsistent results were observed. Moreover, an advanced C-F (electrocoagulation) as well as integration between C-F and Fenton, adsorption, and photocatalytic does not significantly change the toxicological profile of the system. It was found that diverse coagulants and flocculants, species sensitivity, complexity in toxicity testing, and dynamic environmental conditions were some key challenges faced in this field. Finally, it was expected that advances in technology, interdisciplinary collaboration, and a growing awareness of environmental sustainability will drive efforts to develop more effective and eco-friendly coagulants and flocculants, improve toxicity testing methodologies, and enhance the overall efficiency and safety of water and wastewater treatment processes., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In comparison with northern countries, limited data are available on the occurrence and potential toxicity of cyanobacterial blooms in lakes and ponds in sub-Saharan countries. With the aim of enhancing our knowledge on cyanobacteria and their toxins in Africa, we performed a 17-month monitoring of a freshwater ecosystem, Lagoon Aghien (Ivory Coast), which is used for multiple practices by riverine populations and for drinking water production in Abidjan city. The richness and diversity of the cyanobacterial community were high and displayed few variations during the entire survey. The monthly average abundances ranged from 4.1 × 104 to 1.8 × 105 cell mL−1, with higher abundances recorded during the dry seasons. Among the five cyanotoxin families analyzed (anatoxin-a, cylindrospermopsin, homoanatoxin, microcystins, saxitoxin), only microcystins (MC) were detected with concentrations ranging from 0 to 0.364 μg L−1 in phytoplankton cells, from 32 to 1092 μg fresh weight (FW) kg−1 in fish intestines, and from 33 to 383 μg FW kg−1 in fish livers. Even if the MC concentrations in water and fish are low, usually below the thresholds defined in WHO guidelines, these data raise the issue of the relevance of these WHO guidelines for sub-Saharan Africa, where local populations are exposed throughout the year to these toxins in multiple ways. [ABSTRACT FROM AUTHOR]

The imprudent use of insecticides causes the development of resistance in insect pest populations, contamination of the environment, biological imbalance and human intoxication. The use of microbial pathogens combined with insecticides has been proposed as an alternative strategy for insect pest management. This IPM approach may offer effective ways to control pests, in addition to lowering the risk of chemical residues in the environment. Spodoptera litura (Fabricius) is a major pest of many crops like cotton, maize, tobacco, cauliflower, cabbage, and fodder crops globally. Here, we evaluated the combined effects of new chemistry insecticides (chlorantraniliprole and emamectin benzoate) and entomopathogenic bacterial strains, Shewanella sp. (SS4), Thauera sp. (M9) and Pseudomonas sp. (EN4) against S. litura larvae inducing additive and synergistic interactions under laboratory conditions. Both insecticides produced higher larval mortality when applied in combination with bacterial isolates having maximum mortality of 98 and 96% with LC50 of chlorantraniliprole and emamectin benzoate in combination with LC50 of Pseudomonas sp. (EN4) respectively. The lower concentration (LC20) of both insecticides also induced synergism when combined with the above bacterial isolates providing a valuable approach for the management of insect pests. The genotoxic effect of both the insecticides was also evaluated by conducting comet assays. The insecticide treatments induced significant DNA damage in larval hemocytes that further increased in combination treatments. Our results indicated that combined treatments could be a successful approach for managing S. litura while reducing the inappropriate overuse of insecticides. [ABSTRACT FROM AUTHOR]

Energy production plays an important role in seed germination. Elucidating the molecular mechanisms in the main pathways and the energy supply processes that control the germination of Phyllostachys edulis seeds could provide necessary information for the genomic-level improvement of seed crops. In this study, we performed ultrastructural observations and measured the respiration rate, total starch content, crude oil content, and enzymes related to respiratory activities. Transcriptome sequences at five different stages of germination were obtained and analyzed. First, carbohydrate degradation, including lipid and starch metabolism, plays an important role in providing energy during P. edulis seed germination. The total starch and crude oil contents decreased, and starch metabolism and lipid body degradation pathway genes were consistently upregulated during P. edulis seed germination. Second, the glycolytic pathway and citrate cycle in the respiration pathway supply energy during P. edulis seed germination. The respiration intensity increased significantly, with the 6-phosphofructokinase (FPK) enzyme peaking in stage II. Promitochondria broke down into smaller mitochondria, and respiration intensity increased in stages III to IV, with glucose-6-phosphate dehydrogenase and NAD-malate dehydrogenase enzymes reaching peak values in these stages. The AP2 and bHLH proteins were the most commonly upregulated transcription factors related to seed germination and may play significant roles in seed germination. [ABSTRACT FROM AUTHOR]

Key message: ER stress-responsive miRNAs, tae-miR164, tae-miR2916, and tae-miR396e-5p, are essential in response to abiotic stress. Investigating ER stress-responsive miRNAs is necessary to improve plant tolerance to environmental stress. MicroRNAs (miRNAs) play vital regulatory roles in plant responses to environmental stress. Recently, the endoplasmic reticulum (ER) stress pathway, an essential signalling pathway in plants in response to adverse conditions, has been widely studied in model plants. However, miRNAs associated with ER stress response remain largely unknown. Using high-throughput sequencing, three ER stress-responsive miRNAs, tae-miR164, tae-miR2916, and tae-miR396e-5p were identified, and their target genes were confirmed. These three miRNAs and their target genes actively responded to dithiothreitol, polyethylene glycol, salt, heat, and cold stresses. Furthermore, in some instances, the expression patterns of the miRNAs and their corresponding target genes were contrasting. Knockdown of tae-miR164, tae-miR2916, or tae-miR396e-5p using a barley stripe mosaic virus-based miRNA silencing system substantially enhanced the tolerance of wheat plants to drought, salt, and heat stress. Under conditions involving these stresses, inhibiting the miR164 function by using the short tandem target mimic approach in Arabidopsis thaliana resulted in phenotypes consistent with those of miR164-silenced wheat plants. Correspondingly, overexpression of tae-miR164 in Arabidopsis resulted in a decreased tolerance to drought stress and, to some extent, a decrease in tolerance to salt and high temperature. These results revealed that tae-miR164 plays a negative regulatory role in wheat/Arabidopsis in response to drought, salt, and heat stress. Taken together, our study provides new insights into the regulatory role of ER stress-responsive miRNAs in abiotic stress responses. [ABSTRACT FROM AUTHOR]

Background: Maize is an excellent fodder crop due to its high biomass, better palatability, succulency, and nutrition. Studies on morpho-physiological and biochemical characterization of fodder maize are limited. The present study aimed to explore the genetic variation in fodder maize landraces for various morpho-physiological traits and estimation of genetic relationship and population structure. Methods and results: The study on 47 fodder maize landraces revealed significant variation for all morpho-physiological traits except leaf-stem ratio. Plant height, stem girth, leaf-width and number of leaves showed positive correlation with green fodder yield. Morpho-physiological traits-based clustering grouped the landraces into three major clusters, whereas neighbour joining cluster and population structure analysis using 40 SSR markers revealed four and five major groups, respectively. Most landraces of Northern Himalaya-Kashmir and Ludhiana fall into a single group, whereas rest groups mainly had landraces from North-Eastern Himalaya. A total of 101 alleles were generated with mean polymorphic information content value of 0.36 and major allele frequency of 0.68. The pair wise genetic dissimilarity between genotypes ranged from 0.21 to 0.67. Mantel test revealed weak but significant correlation between morphological and molecular distance. Biochemical characterisation of superior landraces revealed significant variation for neutral detergent fibre, acid detergent fibre, cellulose and lignin content. Conclusion: Interestingly, significant, and positive correlation of SPAD with lignin content can be explored to bypass the costly affair of invitro quality assessment for digestibility parameters. The study identified superior landraces and demonstrated the use of molecular markers in genetic diversity assessment and grouping of genotypes for fodder maize improvement. [ABSTRACT FROM AUTHOR]

Nanotechnology has come a long way in our lives. However, it maintains some negative effects on the environment. This study aims to use the land snail Helix aspersa as a bioindicator. Titanium dioxide nanoparticles (TiO2NPs) had been used at 70 and 140 µg/L for two weeks by the spraying method. The oxidative biomarkers, condition index (CI), DNA damage, hemocyte count, and phagocytic activity were estimated. The toxicity of TiO2NPs was determined (LC50 = 544 µg/L). The exposure to TiO2NPs caused a significant reduction of the activities of superoxide dismutase (SOD) and catalase (CAT) in the digestive gland of Helix aspersa (the activity of CAT was 3.4 ± 0.1 (P = 0.001), SOD was 11 ± 1 (P = 0.0002) at concentration 140 µg/L after two weeks). The activity of glutathione peroxidase (GPX) was (1.13 ± 0.01 µ/mg protein at 140 µg/L compared with controls (5.47 ± 0.01 µ/mg protein). The treatment caused DNA damage in the hemocytes (tail DNA % = 8.66 ± 0.02 and tail moment = 52.99 ± 0 at140 µg/L (P = 0.002)). In the digestive gland, both tail DNA % and tail moment increased (tail moment = 78.38 ± 0.08 compared with control = 2.29 ± 0.09 (P = 0.0001)). The total count of hemocytes significantly decreased after two weeks (the average number was 71 ± 1.5 compared with controls 79 ± 1.1 at 140 µg/L). Furthermore, TiO2NPs caused histological alterations in the digestive gland of Helix aspersa. It can be concluded that the Helix aspersa can be used as environmental pollution bioindicator. A comprehensive evaluation of toxic effects induced by TiO2NPs in vivo assays must be investigated. [ABSTRACT FROM AUTHOR]

Carrot is an important vegetable crop worldwide valued for its fleshy edible roots of varied colours. Owing to its highly cross-pollinated nature and small flower size, cytoplasmic male sterility (CMS) is being utilized for hybrid development. Among different types of male sterility, petaloid CMS is widely used for hybrid carrot breeding globally. This study aimed to develop selection criteria for parents in developing heterotic F 1 hybrids using CMS lines. A large number of agro-morphological traits and Simple Sequence Repeats (genomic-SSRs) were used to assess the diversity among parental lines. We developed 60 F 1 hybrids by crossing four petaloid CMS lines and 15 testers in line × tester mating design and evaluated them in replicated randomized block design trial for four vegetative and 11 economic traits. The mean squares of all the traits in line × tester interactions were significant. The estimates of genetic components of variance indicated predominance of non-additive gene action except for root maturity, root length and core diameter. The hybrids with highest per se performance also had significant positive specific combining ability effects. The root yield and root weight showed highest heterosis percentage (33%). The best performing heterotic hybrids were DCatH-5392, DCatH-700 and DCatH-9892. Correlation between genetic distance and relative heterosis of economic traits indicated no significant association and thus genetic distance could not be used to predict heterosis. As most of the yield-related traits were controlled by non-additive gene action, heterosis breeding could be potentially used along with combining ability analysis to reduce time in selection of best parents and crosses in tropical carrot. [ABSTRACT FROM AUTHOR]

Background: Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) also known as tobacco caterpillar, is one of the most serious polyphagous pests that cause economic losses to a variety of commercially important agricultural crops. Over the past few years, many conventional insecticides have been used to control this pest. However, the indiscriminate use of these chemicals has led to development of insecticide resistant populations of S. litura in addition to harmful effects on environment. Due to these ill effects, the emphasis is being laid on alternative eco-friendly control measures. Microbial control is one of the important components of integrated pest management. Thus, in search for novel biocontrol agents, the current work was carried out with the aim to evaluate the insecticidal potential of soil bacteria against S. litura. Results: Among the tested soil bacterial isolates (EN1, EN2, AA5, EN4 and R1), maximum mortality (74%) was exhibited by Pseudomonas sp. (EN4). The larval mortality rate increased in a dose-dependent manner. Bacterial infection also significantly delayed the larval development, reduced adult emergence, and induced morphological deformities in adults of S. litura. Adverse effects were also detected on various nutritional parameters. The infected larvae showed a significant decrease in relative growth and consumption rate as well as efficiency of conversion of ingested and digested food to biomass. Histopathological studies indicated damage to the midgut epithelial layer of larvae due to the consumption of bacteria treated diet. The infected larvae also showed a significantly decreased level of various digestive enzymes. Furthermore, exposure to Pseudomonas sp. also caused DNA damage in the hemocytes of S. litura larvae. Conclusion: Adverse effects of Pseudomonas sp. EN4 on various biological parameters of S. litura indicate that this soil bacterial strain may be used as an effective biocontrol agent against insect pests. [ABSTRACT FROM AUTHOR]

Industrial activities contribute to environmental pollution, particularly through unregulated effluent discharges, causing adverse effects on ecosystems. Vegetable oils, as insoluble substances, exacerbate this pollution, forming impermeable films and affecting the oxygen transfer, leading to serious habitat disruption. Organic wastes, such as soybean texturized waste, spent mushroom substrate, and stabilized poultry litter, were assessed for their efficacy in enhancing the degradation of vegetable oil in contaminated soil. For this purpose, contaminated soil was amended with each of the wastes (10% w/w) using microcosm systems, which were monitored physico-chemically, microbiologically and toxicologically. Results indicate that the wastes promoted significant oil degradation, achieving 83.1, 90.7, and 86.2% removal for soybean texturized waste, spent mushroom substrate, and stabilized poultry litter, respectively, within a 90-day period. Additionally, they positively influenced soil microbial activity, as evidenced by increased levels of culturable microorganisms and hydrolytic microbial activity. While bioassays indicated no phytotoxicity in most cases, soybean texturized waste exhibited inhibitory effects on seed germination and root elongation of Lactuca sativa. This study significantly enhances our comprehension of remediation techniques for sites tainted with vegetable oils, highlighting the critical role of organic waste as eco-friendly agents in soil restoration. Emphasizing the practical implications of these findings is imperative to underscore the relevance and urgency of addressing vegetable oil contamination in soil. Moving forward, tailored strategies considering both contaminant characteristics and soil ecosystem traits are vital for ensuring effective and sustainable soil remediation., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The capacity to form biofilms is a common trait among many microorganisms present on Earth. In this study, we demonstrate for the first time that the fatal pine pitch canker agent, Fusarium circinatum, can lead a biofilm-like lifestyle with aggregated hyphal bundles wrapped in extracellular matrix (ECM). Our research shows F. circinatum's ability to adapt to environmental changes by assuming a biofilm-like lifestyle. This was demonstrated by varying metabolic activities exhibited by the biofilms in response to factors like temperature and pH. Further analysis revealed that while planktonic cells produced small amounts of ECM per unit of the biomass, heat- and azole-exposed biofilms produced significantly more ECM than nonexposed biofilms, further demonstrating the adaptability of F. circinatum to changing environments. The increased synthesis of ECM triggered by these abiotic factors highlights the link between ECM production in biofilm and resistance to abiotic stress. This suggests that ECM-mediated response may be one of the key survival strategies of F. circinatum biofilms in response to changing environments. Interestingly, azole exposure also led to biofilms that were resistant to DNase, which typically uncouples biofilms by penetrating the biofilm and degrading its extracellular DNA; we propose that DNases were likely hindered from reaching target cells by the ECM barricade. The interplay between antifungal treatment and DNase enzyme suggests a complex relationship between eDNA, ECM, and antifungal agents in F. circinatum biofilms. Therefore, our results show how a phytopathogen's sessile (biofilm) lifestyle could influence its response to the surrounding environment., (© 2024 Wiley‐VCH GmbH.)

With its predisposition to adapt to different environments, Cucurbita moschata grows well in various ecosystems. It is not a very exigent plant and has an inherent capacity for plasticity that underlies its large variability. An assessment of the accessions of C. moschata in Cote d'Ivoire shows that the plant exhibits large morphological and phenological variability for all the 28 measured traits. There are outliers among most measured traits. Further analysis indicates the emergence of three ecotypes in congruence with the three distinct ecosystems and their respective bioclimatic characteristics. In the savannah region, characterized by a short rainy season followed by a long dry season, a total yearly rainfall of 900 mm, an elevated daily temperature of 29 °C, and a high relative humidity of 80%, the cline of C. moschata is long and thin, with small leaves, small peduncles and small fruits. It has a high growth rate and accelerated phenology. The mountain region has a very long rainy season followed by a short dry season, a total pluviometry of 1400 mm, an average daily temperature of 27 °C and a relative humidity of 69%. The cline of C. moschata in the mountain region is characterized by a delayed flowering and a delayed fruit maturity, large number of small seeds and large fruits. The forest region has a favorable climate for the growth of C. moschata in Cote d'Ivoire. It has two rainy seasons that alternate with two dry seasons of unequal durations, an annual rainfall of 1200 mm, an average daily temperature of 27 °C and a relative humidity of 70%. The cline of C. moschata in that region has a large girth size, large dimensions of the leaves, long peduncles and larger and heavier fruits. The seeds are also large but in small number. It appears that the anatomy and physiology of the clines are differentiated primarily in response to soil water content and availability for the ontogeny of the plant. [ABSTRACT FROM AUTHOR]

The African continent hosts some of the largest freshwater systems worldwide, characterized by a large distribution and variability of surface waters that play a key role in the water, energy and carbon cycles and are of major importance to the global climate and water resources. Freshwater availability in Africa has now become of major concern under the combined effect of climate change, environmental alterations and anthropogenic pressure. However, the hydrology of the African river basins remains one of the least studied worldwide and a better monitoring and understanding of the hydrological processes across the continent become fundamental. Earth Observation, that offers a cost-effective means for monitoring the terrestrial water cycle, plays a major role in supporting surface hydrology investigations. Remote sensing advances are therefore a game changer to develop comprehensive observing systems to monitor Africa's land water and manage its water resources. Here, we review the achievements of more than three decades of advances using remote sensing to study surface waters in Africa, highlighting the current benefits and difficulties. We show how the availability of a large number of sensors and observations, coupled with models, offers new possibilities to monitor a continent with scarce gauged stations. In the context of upcoming satellite missions dedicated to surface hydrology, such as the Surface Water and Ocean Topography (SWOT), we discuss future opportunities and how the use of remote sensing could benefit scientific and societal applications, such as water resource management, flood risk prevention and environment monitoring under current global change. Article Highlights: The hydrology of African surface water is of global importance, yet it remains poorly monitored and understood Comprehensive review of remote sensing and modeling advances to monitor Africa's surface water and water resources Future opportunities with upcoming satellite missions and to translate scientific advances into societal applications [ABSTRACT FROM AUTHOR]