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Summary: BAK1‐INTERACTING RECEPTOR LIKE KINASE1 (BIR1) is a negative regulator of various aspects of disease resistance and immune responses.Here, we investigated the functional role of soybean (Glycine max) BIR1 (GmBIR1) during soybean interaction with soybean cyst nematode (SCN, Heterodera glycines) and the molecular mechanism through which GmBIR1 regulates plant immunity.Overexpression of wild‐type variant of GmBIR1 (WT‐GmBIR1) using transgenic soybean hairy roots significantly increased soybean susceptibility to SCN, whereas overexpression of kinase‐dead variant (KD‐GmBIR1) significantly increased plant resistance. Transcriptome analysis revealed that genes oppositely regulated in WT‐GmBIR1 and KD‐GmBIR1 upon SCN infection were enriched primarily in defense and immunity‐related functions. Quantitative phosphoproteomic analysis identified 208 proteins as putative substrates of the GmBIR1 signaling pathway, 114 of which were differentially phosphorylated upon SCN infection. In addition, the phosphoproteomic data pointed to a role of the GmBIR1 signaling pathway in regulating alternative pre‐mRNA splicing. Genome‐wide analysis of splicing events provided compelling evidence supporting a role of the GmBIR1 signaling pathway in establishing alternative splicing during SCN infection.Our results provide novel mechanistic insights into the function of the GmBIR1 signaling pathway in regulating soybean transcriptome and spliceome via differential phosphorylation of splicing factors and regulation of splicing events of pre‐mRNA decay‐ and spliceosome‐related genes. [ABSTRACT FROM AUTHOR]

During meiosis, chromosomes with homologous partners undergo synaptonemal complex (SC)‐mediated pairing, while the remaining unpaired chromosomes are heterochromatinized through unpaired silencing. Mechanisms underlying homolog recognition during SC formation are still unclear. Here, we show that the Caenorhabditis elegans Argonaute proteins, CSR‐1 and its paralog CSR‐2, interacting with 22G‐RNAs, are required for synaptonemal complex formation with accurate homology. CSR‐1 in nuclei and meiotic cohesin, constituting the SC lateral elements, were associated with nonsimple DNA repeats, including minisatellites and transposons, and weakly associated with coding genes. CSR‐1‐associated CeRep55 minisatellites were expressing 22G‐RNAs and long noncoding (lnc) RNAs that colocalized with synaptonemal complexes on paired chromosomes and with cohesin regions of unpaired chromosomes. CeRep55 multilocus deletions reduced the efficiencies of homologous pairing and unpaired silencing, which were supported by the csr‐1 activity. Moreover, CSR‐1 and CSR‐2 were required for proper heterochromatinization of unpaired chromosomes. These findings suggest that CSR‐1 and CSR‐2 play crucial roles in homology recognition, achieving accurate SC formation between chromosome pairs and condensing unpaired chromosomes by targeting repeat‐derived lncRNAs. Synopsis: It remains unclear how the homologous sequences of meiotic chromosomes, excluding the pairing center regions, are recognized during synaptonemal complex (SC) formation. This study describes a new model where an Argonaute‐dependent small RNA system is involved in homolog recognition during SC formation in C. elegans. Argonaute protein CSR‐1 and its paralog CSR‐2 interacting with 22G‐RNAs are required for SC formation between chromosome pairs with accurate homology.CSR‐1 and CSR‐2 are also involved in the condensation of unpaired chromosomes.CSR‐1 in nuclei and meiotic cohesin containing COH‐3/4 are associated with non‐simple DNA repeats and weakly with coding genes.CSR‐1 plays pleiotropic roles in the endogenous and exogenous RNAi pathways. [ABSTRACT FROM AUTHOR]

Summary: Acclimation of root growth is vital for plants to survive salt stress. Halophytes are great examples of plants that thrive even under severe salinity, but their salt tolerance mechanisms, especially those mediated by root responses, are still largely unknown.We compared root growth responses of the halophyte Schrenkiella parvula with its glycophytic relative species Arabidopsis thaliana under salt stress and performed transcriptomic analysis of S. parvula roots to identify possible gene regulatory networks underlying their physiological responses.Schrenkiella parvula roots do not avoid salt and experience less growth inhibition under salt stress. Salt‐induced abscisic acid levels were higher in S. parvula roots compared with Arabidopsis. Root transcriptomic analysis of S. parvula revealed the induction of sugar transporters and genes regulating cell expansion and suberization under salt stress. 14C‐labeled carbon partitioning analyses showed that S. parvula continued allocating carbon to roots from shoots under salt stress while carbon barely allocated to Arabidopsis roots. Further physiological investigation revealed that S. parvula roots maintained root cell expansion and enhanced suberization under severe salt stress.In summary, roots of S. parvula deploy multiple physiological and developmental adjustments under salt stress to maintain growth, providing new avenues to improve salt tolerance of plants using root‐specific strategies. [ABSTRACT FROM AUTHOR]

The prevalence of metabolic diseases, such as obesity, diabetes, metabolic syndrome and chronic liver diseases among others, has been rising for several years. Epidemiology and mechanistic (in vivo, in vitro and in silico) toxicology have recently provided compelling evidence implicating the chemical environment in the pathogenesis of these diseases. In this review, we will describe the biological processes that contribute to the development of metabolic diseases targeted by metabolic disruptors, and will propose an integrated pathophysiological vision of their effects on several organs. With regard to these pathomechanisms, we will discuss the needs, and the stakes of evolving the testing and assessment of endocrine disruptors to improve the prevention and management of metabolic diseases that have become a global epidemic since the end of last century. [ABSTRACT FROM AUTHOR]

Problem: Unknown or idiopathic infertility has been associated with urogenital tract dysbiosis, reducing pregnancy and delivery ratios during assisted reproductive treatments (ART). The Ligilactobacillus salivarius PS11610 strain has shown extraordinary antimicrobial activity in vitro against urogenital pathogens as well as other probiotic characteristics. Therefore, an intervention study was performed to evaluate the effect of L. salivarius PS11610 on the microbial composition of urogenital tract in infertile couples with bacterial dysbiosis. Method of study: Seventeen couples undergoing ART diagnosed with unknown infertility were selected. After confirming urogenital dysbiosis, they started a 6‐month treatment with L. salivarius PS11610 (1 dose/12 h for female and 1 dose/24 h for male). Vaginal, seminal, glans, uterine and plasma samples were collected for determination of the microbiome and immune profile at the beginning and the end of the treatment. Results: Supplementation with L. salivarius PS11610 significantly modified the urogenital microbiome composition in male and female samples, solving dysbiosis of 67% of the couples. Pathogens disappeared from the vaginal samples whereas Lactobacilli percentage increased after 3 and 6 months of treatment. Moreover, L. salivarius PS11610 changed the uterine microbiome that could be associated with a change of the uterine immune profile. Additionally, the probiotic intake could be associated with the observed change in the systemic immunological profile of couples. Finally, the pregnant and delivery ratio were improved. Conclusions: Probiotic supplementation with L. salivarius PS11610 improved the male and female urogenital tract microbiome, modulating the immune system and increasing pregnancy success in couples undergoing ART. [ABSTRACT FROM AUTHOR]

Background: The impact of the gut microbiome on the organism has become a growing research focus with the development of 16S rRNA sequencing. However, the effect of the gut microbiome in male reproduction has yet to be investigated. Objective: To overview on possible mechanisms by which the gut microbiome could affect male reproduction and therapeutic opportunities related to the gut microbiome Methods: Authors searched PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane Library for medical subject headings terms and free text words referred to "male infertility" "testis" "gut microbiome" "insulin resistance" "erectile dysfunction" "therapy" "sex hormones" and "genital diseases" until December 2, 2021. Results: Evidence suggests that immune system activation caused by the gut microbiome translocation not only leads to testicular and epididymal inflammation but can also induce insulin resistance together with gastrointestinal hormones such as leptin and ghrelin, which in turn affects the secretion of various sex hormones such as LH, FSH, and T to regulate spermatogenesis. In addition, the gut microbiome can influence spermatogenesis by controlling and metabolizing androgens as well as affecting the blood–testis barrier. It also promotes vascular inflammation by raising trimethylamine‐N‐oxide (TMAO) levels in the blood, which causes erectile dysfunction. The testicular microbiome and gut microbiome can interact to influence male reproductive function. This study discusses therapeutic options such as probiotics, prebiotics, and fecal microbiota transplantation, as well as the challenges and opportunities behind ongoing research, and emphasizes the need for additional research in the future to demonstrate the links and underlying mechanisms between the gut microbiome and male reproduction. Therapeutic options such as probiotics, prebiotics, and fecal microbiota transplantation are potential treatments for male infertility. Discussion and conclusion: Gut microbiota may have a causal role in male reproduction health, therapeutic strategies such as supplementation with appropriate probiotics could be undertaken as a complementary treatment. In the future, additional research is needed to demonstrate the links and underlying mechanisms between the gut microbiome and male reproduction. [ABSTRACT FROM AUTHOR]

A spectre is haunting biomedical research: It appears that a substantial fraction of published research results cannot be reproduced, while spectacularly successful novel treatments developed in experimental models of disease too often fail in clinical trials. A reproducibility crisis has been proclaimed, and bench‐to‐bedside translation appears to be lost in a "valley of death". Both predicaments, non‐reproducibility and translational roadblocks, are connected: Why should we expect to successfully "trans‐late" results to humans, if already "cis‐lation"—that is, the generalization from one experimental setting to an identical or fairly similar one—often fails? [ABSTRACT FROM AUTHOR]

There is emerging evidence of a gut microbiome–skeletal muscle axis. The purpose of this study was to determine if an intact gut microbiome was necessary for skeletal muscle adaptation to exercise. Forty‐two 4‐month‐old female C57BL/6J mice were randomly assigned to untreated (U) or antibiotic‐treated (T) non‐running controls (CU or CT, respectively) or progressive weighted wheel running (PoWeR, P) untreated (PU) or antibiotic‐treated (PT) groups. Antibiotic treatment resulted in disruption of the gut microbiome as indicated by a significant depletion of gut microbiome bacterial species in both CT and PT groups. The training stimulus was the same between PU and PT groups as assessed by weekly (12.35 ± 2.06 vs. 11.09 ± 1.76 km/week, respectively) and total (778.9 ± 130.5 vs. 703.8 ± 112.9 km, respectively) running activity. In response to PoWeR, PT showed less hypertrophy of soleus type 1 and 2a fibres and plantaris type 2b/x fibres compared to PU. The higher satellite cell and myonuclei abundance of PU plantaris muscle after PoWeR was not observed in PT. The fibre‐type shift of PU plantaris muscle to a more oxidative type 2a fibre composition following PoWeR was blunted in PT. There was no difference in serum cytokine levels among all groups suggesting disruption of the gut microbiome did not induce systemic inflammation. The results of this study provide the first evidence that an intact gut microbiome is necessary for skeletal muscle adaptation to exercise. Key points: Dysbiosis of the gut microbiome caused by continuous antibiotic treatment did not affect running activity.Continuous treatment with antibiotics did not result in systemic inflammation as indicated by serum cytokine levels.Gut microbiome dysbiosis was associated with blunted fibre type‐specific hypertrophy in the soleus and plantaris muscles in response to progressive weighted wheel running (PoWeR).Gut microbiome dysbiosis was associated with impaired PoWeR‐induced fibre‐type shift in the plantaris muscle.Gut microbiome dysbiosis was associated with a loss of PoWeR‐induced myonuclei accretion in the plantaris muscle. [ABSTRACT FROM AUTHOR]

Cows are adapted to degrade structural plant carbohydrates (SC), such as cellulose and hemicelluloses, prevailing in grasses. Yet, the need for energy‐dense diets in many intensive dairy production systems has shifted the dairy cattleʼs diet from SC‐rich to high levels of starch. Feeding of starch‐rich diets increases the risk of ruminal acidosis in cows, and feeding starch in the form of grains intensifies the competition over cereal grains and arable land among different livestock species, as well as between livestock and humans. Besides cellulose and hemicelluloses, grasses are also often rich in water‐soluble carbohydrates (WSC), which comprise mono‐, di‐, oligo‐ and polysaccharides (fructans). Although the ruminal fermentation profile of mono‐ and disaccharides resembles that of starch, the degradation of oligo‐ and polysaccharides is slower, and their fermentation elicits a rather protecting effect on ruminal pH. When harvested in an early phase (i.e. ear emergence), grass hay and silages can reach WSC levels up to 150–200 g kg−1 dry matter and energy levels close to starch‐rich diets, allowing a significantly reduced inclusion of concentrate supplements. By doing so, this will enhance both rumen health and the sustainability of milk production. However, because the WSC are chemically very heterogeneous, the patterns and extent of their ruminal fermentation are difficult to predict without a clear analytical characterization. This review article aims to summarize both the benefits and potentials, as well as the challenges, with respect to using WSC‐rich feedstuffs in the nutrition of dairy cattle and their effects on ruminal fermentation characteristics and milk production. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Di‐(2‐ethylhexyl) phthalate (DEHP) is one of the most commonly used plasticizers, and it is widely applied in various plastic products. DEHP is an endocrine‐disrupting chemical (EDC) that has been shown to disrupt the function of reproductive system in females. Although many studies have shown that DEHP potentially causes female reproductive toxicity, including depletion of the primordial follicle and decreased sex hormone production, the specific mechanisms by which DEHP affects female reproduction remain unknown. In recent years, research focused on the intestinal flora has provided an idea to eliminate our confusion, and gut bacterial dysbiosis may contribute to female reproductive toxicity. In the present study, the feces of DEHP‐exposed mice were collected and analyzed using 16S rRNA amplicon sequencing and untargeted global metabolite profiling of metabolomics. DEHP obviously causes reproductive toxicity, including the ovarian organ coefficient, estradiol level, histological features of the ovary and estrus. Furthermore, DEHP exposure alters the structure of the intestinal microbiota community and fecal metabolite profile in mice, suggesting that the reproductive toxicity may be caused by gut bacterial dysbiosis and altered metabolites, such as changes in the levels of short‐chain fatty acid (SCFA). Additionally, it is well known that changes in gut microbiota and fecal metabolites cause inflammation and tissue oxidative stress, expectedly, we found oxidative stress in the ovary and systemic inflammation in DEHP exposed mice. Thus, based on our findings, DEHP exposure may cause gut bacterial dysbiosis and altered metabolite profiles, particularly SCFA profiles, leading to oxidative stress in the ovary and systemic inflammation to ultimately induce female reproductive toxicity. [ABSTRACT FROM AUTHOR]

Summary: The root‐knot nematode Meloidogyne incognita secretes specific effectors (MiEFF) and induces the redifferentiation of plant root cells into enlarged multinucleate feeding 'giant cells' essential for nematode development.Immunolocalizations revealed the presence of the MiEFF18 protein in the salivary glands of M. incognita juveniles. In planta, MiEFF18 localizes to the nuclei of giant cells demonstrating its secretion during plant–nematode interactions. A yeast two‐hybrid approach identified the nuclear ribonucleoprotein SmD1 as a MiEFF18 partner in tomato and Arabidopsis. SmD1 is an essential component of the spliceosome, a complex involved in pre‐mRNA splicing and alternative splicing.RNA‐seq analyses of Arabidopsis roots ectopically expressing MiEFF18 or partially impaired in SmD1 function (smd1b mutant) revealed the contribution of the effector and its target to alternative splicing and proteome diversity. The comparison with Arabidopsis galls data showed that MiEFF18 modifies the expression of genes important for giant cell ontogenesis, indicating that MiEFF18 modulates SmD1 functions to facilitate giant cell formation.Finally, Arabidopsis smd1b mutants exhibited less susceptibility to M. incognita infection, and the giant cells formed on these mutants displayed developmental defects, suggesting that SmD1 plays an important role in the formation of giant cells and is required for successful nematode infection. [ABSTRACT FROM AUTHOR]

Summary: 2,4‐Dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one (DIMBOA) and DIMBOA‐glucoside (DIMBOA‐Glc) are anti‐insect benzoxazinoids in maize, yet very little information is known about how they are regulated.Reverse genetics, kinase activity analysis, phytohormone and DIMBOA/DIMBOA‐Glc quantification, bioassays and transcriptome analysis were employed to study the function of ZmMPK6, a mitogen‐activated protein kinase, in maize response to herbivory.ZmMPK6 was rapidly activated by wounding and simulated herbivory. Silencing ZmMPK6 in maize A188 compromised simulated herbivory‐induced ethylene levels but not those of jasmonic acid or salicylic acid, and the ZmMPK6‐silenced plants exhibited elevated DIMBOA/DIMBOA‐Glc and insect resistance. An ethylene complementation experiment revealed that ZmMPK6 repressed the accumulation of DIMBOA/DIMBOA‐Glc in an ethylene‐dependent manner. Transcriptome analysis revealed that ZmMPK6 might meditate the transcription of BX1 by controlling a MYB transcription factor that is likely to be located in the ethylene signalling pathway and, furthermore, ZmMPK6 and ethylene signalling also specifically and commonly regulate the transcription of other benzoxazinoid biosynthetic genes. We also show that different maize lines have very different responses to simulated herbivory in terms of ZmMPK6 activation, ethylene emission and benzoxazinoid levels.These results uncover that ZmMPK6 and ethylene pathway are novel repressors of DIMBOA/DIMBOA‐Glc and provide new insight into the regulatory mechanisms underlying these two pathways. [ABSTRACT FROM AUTHOR]

A diversity of bacteria, protozoans and viruses ("endozoites") were recently uncovered within healthy tissues including the human brain. By contrast, it was already recognized a century ago that healthy plants tissues contain abundant endogenous microbes ("endophytes"). Taking endophytes as an informative precedent, we overview the nature, prevalence, and role of endozoites in mammalian tissues, centrally focusing on the brain, concluding that endozoites are ubiquitous in diverse tissues. These passengers often remain subclinical, but they are not silent. We address their routes of entry, mechanisms of persistence, tissue specificity, and potential to cause long‐term behavioral changes and/or immunosuppression in mammals, where rabies virus is the exemplar. We extend the discussion to Herpesviridae, Coronaviridae, and Toxoplasma, as well as to diverse bacteria and yeasts, and debate the advantages and disadvantages that endozoite infection might afford to the host and to the ecosystem. We provide a clinical perspective in which endozoites are implicated in neurodegenerative disease, anxiety/depression, and schizophrenia. We conclude that endozoites are instrumental in the delicate balance between health and disease, including age‐related brain disease, and that endozoites have played an important role in the evolution of brain function and human behavior. [ABSTRACT FROM AUTHOR]

Plants optimize water use and carbon assimilation via transient regulation of stomata resistance and by limiting hydraulic conductivity in a long‐term response of xylem anatomy. We postulated that without effective hydraulic regulation plants would permanently restrain water loss and photosynthetic productivity under salt stress conditions. We compared wild‐type tomatoes to a transgenic type (TT) with impaired stomatal control. Gas exchange activity, biomass, starch content, leaf area and root traits, mineral composition and main stems xylem anatomy and hydraulic conductivity were analyzed in plants exposed to salinities of 1 and 4 dS m−1 over 60 days. As the xylem cannot easily readjust to different environmental conditions, shifts in its anatomy and the permanent effect on plant hydraulic conductivity kept transpiration at lower levels under unstressed conditions and maintained it under salt‐stress, while sustaining higher but inefficient assimilation rates, leading to starch accumulation and decreased plant biomass, leaf and root area and root length. Narrow conduits in unstressed TT plants were related to permanent restrain of hydraulic conductivity and plant transpiration. Under salinity, TT plants followed the atmospheric water demand, sustained similar transpiration rate from unstressed to salt‐stressed conditions and possibly maintained hydraulic integrity, due to likely impaired hydraulic regulation, wider conduits and higher hydraulic conductivity. The accumulation of salts and starch in the TT plants was a strong evidence of salinity tolerance via osmotic regulation, also thought to help to maintain the assimilation rates and transpiration flux under salinity, although it was not translated into higher growth. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is a widely studied and well‐recognised endocrine‐disrupting chemical, and one of the current issues is its safe replacement by various analogues. Using larva zebrafish as a model, the present study reveals that moderate and chronic exposure to BPA analogues such as bisphenol S, bisphenol F and bisphenol AF may also affect vertebrate neurodevelopment and locomotor activity. Several parameters of embryo‐larval development were investigated, such as mortality, hatching, number of mitotically active cell, as defined by 5‐bromo‐2'‐deoxyuridine incorporation and proliferative cell nuclear antigen labelling, aromatase B protein expression in radial glial cell and locomotor activity. Our results show that exposure to several bisphenol analogues induced an acceleration of embryo hatching rate. At the level of the developing brain, a strong up‐regulation of the oestrogen‐sensitive Aromatase B was also detected in the hypothalamic region. This up‐regulation was not associated with effects on the numbers of mitotically active progenitors nor differentiated neurones in the preoptic area and in the nuclear recessus posterior of the hypothalamus zebrafish larvae. Furthermore, using a high‐throughput video tracking system to monitor locomotor activity in zebrafish larvae, we show that some bisphenol analogues, such as bisphenol AF, significantly reduced locomotor activity following 6 days of exposure. Taken together, our study provides evidence that BPA analogues can also affect the neurobehavioural development of zebrafish. [ABSTRACT FROM AUTHOR]

Summary: Root growth control plays an important role in plant adaptation to drought stress, but the underlying molecular mechanisms of this control remain largely elusive.Here, a root‐specific nuclear factor Y (NF‐Y) transcription factor PdNF‐YB21 was isolated from Populus. The functional mechanism of PdNF‐YB21 was characterised by various morphological, physiological, molecular, biochemical and spectroscopy techniques.Overexpression of PdNF‐YB21 in poplar promoted root growth with highly lignified and enlarged xylem vessels, resulting in increased drought resistance. By contrast, CRISPR/Cas9‐mediated poplar mutant nf‐yb21 exhibited reduced root growth and drought resistance. PdNF‐YB21 interacted with PdFUSCA3 (PdFUS3), a B3 domain transcription factor. PdFUS3 directly activated the promoter of the abscisic acid (ABA) synthesis key gene PdNCED3, resulting in a significant increase in root ABA content in poplars subjected to water deficit. Coexpression of poplar NF‐YB21 and FUS3 significantly enhanced the expression of PdNCED3. Furthermore, ABA promoted indoylacetic acid transport in root tips, which ultimately increased root growth and drought resistance.Taken together, our data indicate that NF‐YB21–FUS3‐NCED3 functions as an important avenue in auxin‐regulated poplar root growth in response to drought. [ABSTRACT FROM AUTHOR]

The hypothalamus and hippocampus are sensitive to early exposure to endocrine disrupting chemicals (EDCs). Two EDCs that have raised particular concerns are bisphenol A (BPA), a widely prevalent chemical in many common household items, and genistein (GEN), a phyto‐oestrogen present in soy and other plants. We hypothesised that early exposure to BPA or GEN may lead to permanent effects on gene expression profiles for both coding RNAs (mRNAs) and microRNAs (miRs), which can affect the translation of mRNAs. Such EDC‐induced biomolecular changes may affect behavioural and metabolic patterns. California mice (Peromyscus californicus) male and female offspring were developmentally exposed via the maternal diet to BPA (5 mg kg‐1 feed weight low dose [LD] and 50 mg kg‐1 feed weight upper dose [UD]), GEN (250 mg kg‐1 feed weight) or a phyto‐oestrogen‐free diet (AIN) control. Behavioural and metabolic tests were performed at 180 days of age. A quantitative polymerase chain reacttion analysis was performed for candidate mRNAs and miRs in the hypothalamus and hippocampus. LD BPA and GEN exposed California mice offspring showed socio‐communication impairments. Hypothalamic Avp, Esr1, Kiss1 and Lepr were increased in LD BPA offspring. miR‐153 was elevated but miR‐181a was reduced in LD BPA offspring. miR‐9 and miR‐153 were increased in the hippocampi of LD BPA offspring, whereas GEN decreased hippocampal miR‐7a and miR‐153 expression. Correlation analyses revealed neural expression of miR‐153 and miR‐181a was associated with socio‐communication deficits in LD BPA individuals. The findings reveal a cause for concern such that developmental exposure of BPA or GEN in California mice (and potentially by translation in humans) can lead to long standing neurobehavioural consequences. [ABSTRACT FROM AUTHOR]

Prairie reconstruction has become a common method for reestablishing tallgrass prairie communities in the central United States. With the objective of creating plant communities that approximate remnant (reference) prairies, managers are interested in identifying: (1) best methods for reconstructing reference community conditions; (2) the rate of change in plant communities through time following reconstruction; and (3) species present in remnant communities but missing from reconstructed communities. This information is important in the development of adaptive management strategies during active reconstruction. We used a chronosequence approach to assess the success of two reconstruction methods in emulating local, reference remnant prairie plant communities. We compared broadcast dormant seeding following two types of site preparation, agricultural cropping (Crop) or herbicide control in existing grass assemblages (Grass), and remnant communities. The Crop site preparation method resulted in a rapid increase in richness shortly following seeding. Although more similar to remnant assemblages initially, the Grass method took longer for mean coefficient of conservatism and floristic quality index to approach conditions of the reference communities. However, neither method resulted in plant community compositions that converged with the reference through time. Further, indicator species analysis identified a diverse assemblage of species lacking from the reconstructed prairies. These results suggest the need to develop management strategies for establishing the "missing" species during reconstruction and provide further support for protection and conservation of existing remnant prairies. [ABSTRACT FROM AUTHOR]

In plants, CALCIUM‐DEPENDENT PROTEIN KINASES (CDPKs/CPKs) are involved in calcium signaling in response to endogenous and environmental stimuli. Here, we report that ZmCPK11, one of maize CDPKs, participates in salt stress response and tolerance. Salt stress induced expression and upregulated the activity of ZmCPK11 in maize roots and leaves. Activation of ZmCPK11 upon salt stress was also observed in roots and leaves of transgenic Arabidopsis plants expressing ZmCPK11. The transgenic plants showed a long‐root phenotype under control conditions and a short‐root phenotype under NaCl, abscisic acid (ABA) or jasmonic acid (JA) treatment. Analysis of ABA and JA content in roots indicated that ZmCPK11 can mediate root growth by regulating the levels of these phytohormones. Moreover, 4‐week‐old transgenic plants were more tolerant to salinity than the wild‐type plants. Their leaves were less chlorotic and showed weaker symptoms of senescence accompanied by higher chlorophyll content and higher quantum efficiency of photosystem II. The expression of Na+/K+ transporters (HKT1, SOS1 and NHX1) and transcription factors (CBF1, CBF2, CBF3, ZAT6 and ZAT10) with known links to salinity tolerance was upregulated in roots of the transgenic plants upon salt stress. Furthermore, the transgenic plants accumulated less Na+ in roots and leaves under salinity, and showed a higher K+/Na+ ratio in leaves. These results show that the improved salt tolerance in ZmCPK11‐transgenic plants could be due to an upregulation of genes involved in the maintenance of intracellular Na+ and K+ homeostasis and a protection of photosystem II against damage. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) is an important phytohormone regulating plant growth, development, and stress responses. It has an essential role in multiple physiological processes of plants, such as stomatal closure, cuticular wax accumulation, leaf senescence, bud dormancy, seed germination, osmotic regulation, and growth inhibition among many others. Abscisic acid controls downstream responses to abiotic and biotic environmental changes through both transcriptional and posttranscriptional mechanisms. During the past 20 years, ABA biosynthesis and many of its signaling pathways have been well characterized. Here we review the dynamics of ABA metabolic pools and signaling that affects many of its physiological functions. [ABSTRACT FROM AUTHOR]

Hypocotyl elongation is an early event in plant growth and development and is sensitive to fluctuations in light, temperature, water potential and nutrients. Most research on hypocotyl elongation has focused on the regulatory mechanism of a single environment factor. However, information about combined effects of multi‐environment factors remains unavailable, and overlapping sites of the environmental factors signaling pathways in the regulation of hypocotyl elongation remain unclear. To identify how cross‐talks among light intensity, temperature and water potential regulate hypocotyl elongation in Brassica rapa L. ssp. chinesis, a comprehensive isobaric tag for relative and absolute quantitation‐based proteomic approach was adopted. In total, 7259 proteins were quantified, and 378 differentially expressed proteins (DEPs) were responsive to all three environmental factors. The DEPs were involved in a variety of biochemical processes, including signal transduction, cytoskeletal organization, carbohydrate metabolism, cell wall organization, protein modification and transport. The DEPs did not function in isolation, but acted in a large and complex interaction network to affect hypocotyl elongation. Among the DEPs, phyB was outstanding for its significant fold change in quantity and complex interaction networks with other proteins. In addition, changes of sensitivity to environmental factors in phyB‐9 suggested a key role in the regulation of hypocotyl elongation. Overall, the data presented in this study show a profile of proteins interaction network in response to light intensity, temperature and water potential and provides molecular basis of hypocotyl elongation in B. rapa. [ABSTRACT FROM AUTHOR]

Abstract: Melatonin and serotonin are important signaling and stress mitigating molecules that play important roles across growth and development in plants. Despite many well‐documented responses, a systematic investigation of the entire metabolic pathway (tryptophan, tryptamine, and N‐acetylserotonin) does not exist, leaving many open questions. The objective of this study was to determine the responses of Hypericum perforatum (L.) to melatonin, serotonin, and their metabolic precursors. Two well‐characterized germplasm lines (#4 and 112) created by mutation and a haploid breeding program were compared to wild type to identify specific responses. Germplasm line 4 has lower regenerative and photosynthetic capacity than either wild type or line 112, and there are documented significant differences in the chemistry and physiology of lines 4 and 112. Supplementation of the culture media with tryptophan, tryptamine, N‐acetylserotonin, serotonin, or melatonin partially reversed the regenerative recalcitrance and growth impairment of the germplasm lines. Quantification of phytohormones revealed crosstalk between the indoleamines and related phytohormones including cytokinin, salicylic acid, and abscisic acid. We hypothesize that melatonin and serotonin function in coordination with their metabolites in a cascade of phytochemical responses including multiple pathways and phytohormone networks to direct morphogenesis and protect photosynthesis in H. perforatum. [ABSTRACT FROM AUTHOR]

It is becoming well established that the gut microbiome has a profound impact on human health and disease. In this review, we explore how steroids can influence the gut microbiota and, in turn, how the gut microbiota can influence hormone levels. Within the context of the gut microbiome‐brain axis, we discuss how perturbations in the gut microbiota can alter the stress axis and behaviour. In addition, human studies on the possible role of gut microbiota in depression and anxiety are examined. Finally, we present some of the challenges and important questions that need to be addressed by future research in this exciting new area at the intersection of steroids, stress, gut‐brain axis and human health. [ABSTRACT FROM AUTHOR]

The oxygen and hydrogen isotope composition of water in the leaf growth-and-differentiation zone, LGDZ, (δ18OLGDZ, δ2HLGDZ) of grasses influences the isotopic composition of leaf cellulose (oxygen) and wax (hydrogen) - important for understanding (paleo)environmental and physiological information contained in these biological archives - but is presently unknown., This work determined δ18OLGDZ and δ2HLGDZ, 18O- and 2H-enrichment of LGDZ (∆18OLGDZ and ∆2HLGDZ), and the 18O- and 2H-enrichment of leaf blade water (∆18OLW, ∆2HLW) in two C3 and three C4 grasses grown at high and low vapor pressure deficit ( VPD)., The proportion of unenriched water ( px) in the LGDZ ranged from 0.9 to 1.0 for 18O and 1.0 to 1.2 for 2H. VPD had no effect on the proportion of 18O- and 2H-enriched water in the LGDZ, and species effects were small or nonsignificant. Deuterium discrimination caused depletion of 2H in LGDZ water, increasing (apparent) px-values > 1.0 in some cases., The isotopic composition of water in the LGDZ was close to that of source water, independent of VPD and much less enriched than previously supposed, but similar to reported xylem water in trees. The well-constrained px will be useful in future investigations of oxygen and hydrogen isotopic fractionation during cellulose and wax synthesis, respectively. [ABSTRACT FROM AUTHOR]

Chemical and psychological stressors can exert long lasting changes in brain function and behaviour. Changes in DNA methylation have been shown to be an important mechanism mediating long lasting changes in neural function and behaviour, especially for anxiety-like or stress responses. In the present study, we examined the effects of either a social or chemical stressor on DNA methyltransferase (DNMT) gene expression in the amygdala, an important brain region modulating stress responses and anxiety. In adult California mice (Peromyscus californicus) that were naïve to social defeat, females had higher levels of Dnmt1 expression in punch samples of the central amygdala (CeA) than males. In addition, mice that underwent social defeat stress showed reduced Dnmt1 and Dnmt3a expression in the CeA of females but not males. A second study using more anatomically specific punch samples replicated these effects for Dnmt1. Perinatal exposure (spanning from periconception through lactation) to bisphenol A or ethinyl oestradiol (oestrogens in birth control pills) also abolished sex differences in Dnmt1 expression in the CeA but not the basolateral amygdala. These findings identify a robust sex difference in Dnmt1 expression in the CeA that is sensitive to both psychological and chemical stressors. Future studies should aim to examine the impact of psychological and chemical stressors on DNA methylation in the CeA and also investigate whether Dnmt1 may have an underappreciated role in plasticity in behaviour. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms regulating root development under drought conditions is an important question for plant biology and world agriculture., We examine the effect of osmotic stress on abscisic acid (ABA), cytokinin and ethylene responses and how they mediate auxin transport, distribution and root growth through effects on PIN proteins. We integrate experimental data to construct hormonal crosstalk networks to formulate a systems view of root growth regulation by multiple hormones., Experimental analysis shows: that ABA-dependent and ABA-independent stress responses increase under osmotic stress, but cytokinin responses are only slightly reduced; inhibition of root growth under osmotic stress does not require ethylene signalling, but auxin can rescue root growth and meristem size; osmotic stress modulates auxin transporter levels and localization, reducing root auxin concentrations; PIN1 levels are reduced under stress in an ABA-dependent manner, overriding ethylene effects; and the interplay among ABA, ethylene, cytokinin and auxin is tissue-specific, as evidenced by differential responses of PIN1 and PIN2 to osmotic stress., Combining experimental analysis with network construction reveals that ABA regulates root growth under osmotic stress conditions via an interacting hormonal network with cytokinin, ethylene and auxin. [ABSTRACT FROM AUTHOR]

Production of phytohormones is one of the main mechanisms to explain the beneficial effects of plant growth‐promoting rhizobacteria (PGPR) such as Azospirillum sp. The PGPRs induce plant growth and development, and reduce stress susceptibility. However, little is known regarding the stress‐related phytohormone abscisic acid (ABA) produced by bacteria. We investigated the effects of Azospirillum brasilense Sp 245 strain on Arabidopsis thaliana Col‐0 and aba2‐1 mutant plants, evaluating the morphophysiological and biochemical responses when watered and in drought. We used an in vitro‐grown system to study changes in the root volume and architecture after inoculation with Azospirillum in Arabidopsis wild‐type Col‐0 and on the mutant aba2‐1, during early growth. To examine Arabidopsis development and reproductive success as affected by the bacteria, ABA and drought, a pot experiment using Arabidopsis Col‐0 plants was also carried out. Azospirillum brasilense augmented plant biomass, altered root architecture by increasing lateral roots number, stimulated photosynthetic and photoprotective pigments and retarded water loss in correlation with incremented ABA levels. As well, inoculation improved plants seed yield, plants survival, proline levels and relative leaf water content; it also decreased stomatal conductance, malondialdehyde and relative soil water content in plants submitted to drought. Arabidopsis inoculation with A. brasilense improved plants performance, especially in drought. [ABSTRACT FROM AUTHOR]

Contents With an aim to improve the efficiency of yak-bovine interspecies somatic cell nuclear transfer (i SCNT), this study investigated the effect of different culture systems on the development, quality and gene expression profile of yak-bovine i SCNT embryo. Reconstructed embryos were cultured in modified synthetic oviductal fluid (m SOF) or relative defined culture medium ( RDCM) with 5% or 20% oxygen tension. Relative m RNA abundance of Oct-4, IFNT, IGF-2, Bax, GPX-1, SOD-1, CAT and GSS was analysed in blastocysts with q RT-PCR. The blastocyst formation rate in RDCM under 5% oxygen tension was significantly higher than that under 20% oxygen tension ( P < 0.05). The total cell number of blastocyst derived from RDCM with 20% oxygen tension was lower than that of other groups, whereas the group of RDCM with 5% oxygen tension showed a beneficial effect on apoptosis index and tolerance to cryopreservation ( P < 0.05). However, under the same oxygen tension, the m RNA abundance of IFNT of RDCM groups was higher than that of the m SOF groups. In addition, high oxygen tension during in vitro culture ( IVC) with RDCM significantly increases the m RNA expression of oxidative stress-related genes ( GPX-1, SOD-1, CAT and GSS) ( P < 0.05). 3, 4-Dihydroxyflavone ( DHF) during high oxygen tension was able to improve the cloned blastocyst formation rate in RDCM ( P < 0.05). These results for the first time showed that low oxygen tension and RDCM could improve the developmental competence and quality and alleviate the oxidative stress for yak-bovine i SCNT embryo during IVC. [ABSTRACT FROM AUTHOR]

Maintenance of root growth is essential for plant adaptation to soil drying. Here, we tested the hypothesis that auxin transport is involved in mediating ABA's modulation by activating proton secretion in the root tip to maintain root growth under moderate water stress., Rice and Arabidopsis plants were raised under a hydroponic system and subjected to moderate water stress (−0.47 MPa) with polyethylene glycol ( PEG). ABA accumulation, auxin transport and plasma membrane H+- ATPase activity at the root tip were monitored in addition to the primary root elongation and root hair density., We found that moderate water stress increases ABA accumulation and auxin transport in the root apex. Additionally, ABA modulation is involved in the regulation of auxin transport in the root tip. The transported auxin activates the plasma membrane H+- ATPase to release more protons along the root tip in its adaption to moderate water stress. The proton secretion in the root tip is essential in maintaining or promoting primary root elongation and root hair development under moderate water stress., These results suggest that ABA accumulation modulates auxin transport in the root tip, which enhances proton secretion for maintaining root growth under moderate water stress. [ABSTRACT FROM AUTHOR]

Contents Notable distinctions between an embryonic stem cell (ESC) and somatic cell are that an ESC can maintain an undifferentiated state indefinitely, self-renew, and is pluripotent, meaning that the ESC can potentially generate cells representing all the three primordial germ layers and contribute to the terminally differentiated cells of a conceptus. These attributes make the ESC an ideal source for genome editing for both agricultural and biomedical applications. Although, ESC lines have been successfully established from rodents and primates, authentic ungulate stem cell lines on the contrary are still not available. Outstanding issues including but not limited to differences in pluripotency characteristics among the existing ESC lines, pre-implantation embryo development, pluripotency pathways, and culture conditions plague our efforts to establish authentic ESC lines from farm animals. In this review, we highlight some of these issues and discuss how the recent derivation of induced pluripotent stem cells (iPSCs) might augur the establishment of robust authentic ESC lines from farm animals. [ABSTRACT FROM AUTHOR]

Contents The survival and development of pre-implantation embryos are determinant factors affecting the outcome of animal reproduction. It is essential to transfer the expression of the genetic material from maternal sources, that is the ovum to the zygote before implantation to ensure successful development. Differentiation and transformation of blastomeres initiated during the morula and blastocyst stages is an important step of the embryonic development prior to implantation. We collected morula and early blastocyst samples from pure-bred Landrace pigs in vivo to study the differential gene expression patterns at these two stages. Total RNA was extracted from individual embryos and two rounds of amplification were employed. Two micrograms of antisense RNA, targets, were prepared and hybridized with each of four custom made oligo microarrays representing 24 000 porcine genes. The analyses of replicate hybridizations showed that among the 24 000 genes, 162 genes were expressed fivefold or greater in the morula compared to early blastocysts and 2126 genes were expressed fivefold or greater in early blastocysts compared to the morula. Of these differentially expressed genes, 1429 genes were functionally annotated with related human Gene Ontology terms. In addition to basic metabolic processes, genes related to signal transduction, transportation and cell differentiation were found in both stages and were up-regulated as embryo development proceeded. Real time polymerase chain reaction was utilized to quantify 12 genes differentially expressed in the 2 embryonic stages and validated the reliability of major evidences shown in microarrays. In conclusion, we have obtained a preliminary landscape of genes differentially expressed during the transition from morula to early blastocysts in pigs and showed a generally increased transcriptional activity, perhaps in preparation for implantation. Our results provide an opportunity to study the functions of these genes in relation to the development and survival of pre-implantation porcine embryos. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

Currently, the molecular regulation mechanisms involved in the early development of maize brace root are poorly known. To gain insight into the transcriptome dynamics that are associated with its development, genome-wide gene expression profiling was conducted by Solexa sequencing (Illumina Inc., San Diego, CA, USA). More than five million tags were generated from the stem node tissues without and with just-emerged brace roots, including 149 524 and 178 131 clean tags in the two libraries, respectively. Of these, 82 864 (55.4%) and 91 678 (51.5%) tags were matched to the reference genes. The most differentially expressed tags with a log ratio > 2 or < −2 ( P < 0.001) were analyzed further, representing 143 up-regulated and 152 down-regulated genes, except for unknown transcripts, which were classified into 11 functional categories. The most enriched categories were those of metabolism, signal transduction and cellular transport. Many genes or biological pathways were found to be commonly shared between brace root and lateral or adventitious root development, such as genes participating in cell wall degradation and synthesis, auxin transport and signaling, ethylene signaling, etc. Next, the expression patterns of 20 genes were assessed by quantitative real-time PCR, and the results obtained showed general agreement with the Solexa analysis. Furthermore, a comparison of the brace root transcriptome with that of maize primary root revealed substantial differences in the categories and abundances of expressed transcripts. In conclusion, we first reveal the complex changes in the transcriptome during the early development of maize brace root and provide a comprehensive set of data that are essential for understanding its molecular regulation. [ABSTRACT FROM AUTHOR]

Plants can escape from specific environmental stresses through active growth strategies. Here, we compared two such stress-escape syndromes to investigate whether plants use conserved signal transduction pathways to escape from different stresses. Full submergence is a threat to terrestrial plants as it cuts off their access to oxygen and CO2. Proximate neighbors, in contrast, take away resources such as light. Both submergence and shade can be escaped through rapid shoot elongation. We analysed the precise kinetics and physiological control of petiole elongation responses to shade and submergence in the flood-tolerant species Rumex palustris. We found that petiole elongation induced by submergence and that induced by shade occurred with similar kinetics, both involving cell expansion. These responses were induced by two different signals, elevated ethylene and a reduced red : far-red light ratio (R : FR), respectively. A downstream target for ethylene was abscisic acid, but low R : FR appeared to act independently of this hormone. Gibberellin, however, appeared to be essential to both ethylene- and low R : FR-induced petiole elongation. We propose that gibberellin and expansins, a family of cell wall-loosening proteins, represent elements of a conserved growth machinery that is activated by stress-specific signaling events to regulate escape from stress. [ABSTRACT FROM AUTHOR]

Following the idea of partial root-zone drying (PRD) in crop cultivation, the morphological and physiological responses to partial root osmotic stress (PROS) and whole root osmotic stress (WROS) were investigated in rice. WROS caused stress symptoms like leaf rolling and membrane leakage. PROS stimulated stress signals, but did not cause severe leaf damage. By proteomic analysis, a total of 58 proteins showed differential expression after one or both treatments, and functional classification of these proteins suggests that stress signals regulate photosynthesis, carbohydrate and energy metabolism. Two other proteins (anthranilate synthase and submergence-induced nickel-binding protein) were upregulated only in the PROS plants, indicating their important roles in stress resistance. Additionally, more enzymes were involved in stress defense, redox homeostasis, lignin and ethylene synthesis inWROS leaves, suggesting a more comprehensive regulatory mechanism induced by osmotic stress. This study provides new insights into the complex molecular networks within plant leaves involved in the adaptation to osmotic stress and stress signals. [ABSTRACT FROM AUTHOR]

Abies fabri (Mast.) Craib. ( A. fabri) is an endemic and dominant species in typical subalpine dark coniferous forests distributed in mountainous regions of Western Sichuan, China. We investigated the ecophysiological responses of A. fabri seedlings to short-term experimental drought, nitrogen supply and their interaction. Drought stress was created by excluding natural precipitation with automatically controlled plastic roof that covered the seedlings. Nitrogen fertilization was applied weekly by spraying over seedlings ammonium nitrate solution (50 kg N ha−1 year−1) during the growing season of 2009. The results showed that drought stress decreased leaf relative water content (RWC), whereas it caused marked increases in root mass ratio (RMR) and root/shoot mass ratio by 6.19 and 10.39%, respectively, as compared with the control. Drought stress increased malondialdehyde (MDA) content, electrolyte leakage, proline content, soluble sugars content and the activities of antioxidant enzymes, whereas nitrogen supply decreased MDA content, but enhanced activities of some antioxidant enzymes [especially peroxidase (POD)]. In the drought stressed plots, nitrogen supply increased RWC and decreased the content of MDA. The combination of drought stress and nitrogen supply also decreased the activities of antioxidant enzymes. These results indicated that the negative effects of drought stress on A. fabri seedlings might be alleviated by nitrogen supply. [ABSTRACT FROM AUTHOR]

•Drought induces root death in plants; however, the nature and characteristics of root cell death and its underlying mechanisms are poorly understood. Here, we provide a systematic analysis of cell death in the primary root tips in Arabidopsis during water stress. •Root tip cell death occurs when high water deficit is reached. The dying cells were first detected in the apical meristem of the primary roots and underwent active programmed cell death (PCD). Transmission electron microscopic analysis shows that the cells undergoing induced death had unambiguous morphological features of autophagic cell death, including an increase in vacuole size, degradation of organelles, and collapse of the tonoplast and the plasma membrane. The results suggest that autophagic PCD occurs as a response to severe water deficit. •Significant accumulation of reactive oxygen species (ROS) was detected in the stressed root tips. Expression of BAX inhibitor-1 ( AtBI1) was increased in response to water stress, and atbi1-1 displayed accelerated cell death, indicating that AtBI1 and the endoplasmic reticulum (ER) stress response pathway both modulate water stress-induced PCD. •These findings form the basis for further investigations into the mechanisms underlying the PCD and its role in developmental plasticity of root system architecture and subsequent adaptation to water stress. [ABSTRACT FROM AUTHOR]

• The tropical intertidal ecosystem is defined by trees – mangroves – which are adapted to an extreme and extremely variable environment. The genetic basis underlying these adaptations is, however, virtually unknown. Based on advances in pyrosequencing, we present here the first transcriptome analysis for plants for which no prior genomic information was available. We selected the mangroves Rhizophora mangle (Rhizophoraceae) and Heritiera littoralis (Malvaceae) as ecologically important extremophiles employing markedly different physiological and life-history strategies for survival and dominance in this extreme environment. • For maximal representation of conditional transcripts, mRNA was obtained from a variety of developmental stages, tissues types, and habitats. For each species, a normalized cDNA library of pooled mRNAs was analysed using GSFLX pyrosequencing. • A total of 537 635 sequences were assembled de novo and annotated as > 13 000 distinct gene models for each species. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology annotations highlighted remarkable similarities in the mangrove transcriptome profiles, which differed substantially from the model plants Arabidopsis and Populus. • Similarities in the two species suggest a unique mangrove lifestyle overarching the effects of transcriptome size, habitat, tissue type, developmental stage, and biogeographic and phylogenetic differences between them. [ABSTRACT FROM AUTHOR]

Water-deficit stress poses unique challenges to plant cells dependent on a hydrostatic skeleton and a polysaccharide-rich cell wall for growth and development. How the plant cell wall is adapted to loss of water is of interest in developing a general understanding of water stress tolerance in plants and of relevance in strategies related to crop improvement. Drought tolerance involves adaptations to growth under reduced water potential and the concomitant restructuring of the cell wall that allow growth processes to occur at lower water contents. Desiccation tolerance, by contrast, is the evolution of cell walls that are capable of losing the majority of cellular water without suffering permanent and irreversible damage to cell wall structure and polymer organization. This minireview highlights common features and differences between these two water-deficit responses observed in plants, emphasizing the role of the cell wall, while suggesting future research avenues that could benefit fundamental understanding in this area. [ABSTRACT FROM AUTHOR]

Plant roots are required for the acquisition of water and nutrients, for responses to abiotic and biotic signals in the soil, and to anchor the plant in the ground. Controlling plant root architecture is a fundamental part of plant development and evolution, enabling a plant to respond to changing environmental conditions and allowing plants to survive in different ecological niches. Variations in the size, shape and surface area of plant root systems are brought about largely by variations in root branching. Much is known about how root branching is controlled both by intracellular signalling pathways and by environmental signals. Here, we will review this knowledge, with particular emphasis on recent advances in the field that open new and exciting areas of research. [ABSTRACT FROM AUTHOR]

In this work, the effects of osmotic stress and exogenous auxin (indole-3-butyric acid, IBA) on root morphology and nitric oxide (NO) generation in roots were compared in pea plants. Five-day-old plants were treated with 0, 10−3, 10−4, 10−5, 10−6, 10−7, 10−8 or 10−9 M IBA or with PEG 6000 at concentrations that determined 0, 50, 100, 200 or 400 mOsm in the medium, during 5 days. NO generation was examined by in situ and in vivo fluorescence method. Increasing concentrations of PEG as well as IBA resulted in shortening of primary root (PR), enhancement of lateral root (LR) number and significant increase of NO generation. Time-dependent investigations revealed that in the case of IBA treatments, the LR number increased in parallel with an intensified NO generation, while elongation of PR was not followed by changes in NO levels. Under osmotic stress, the time curve of NO development was distinct compared with that of IBA-treated roots, because significantly, the appearance of lateral initials was preceded by a transient burst of NO. This early phase of NO generation under osmotic stress was clearly distinguishable from that which accompanied LR initiation. It is concluded that osmotic stress and the presence of exogenous auxin resulted in partly similar root architecture but different time courses of NO synthesis. We suppose that the early phase of NO generation may fulfill a role in the osmotic stress-induced signalization process leading to the modification of root morphology. [ABSTRACT FROM AUTHOR]

Elevated CO2 appears to be a significant factor in global warming, which will likely lead to drought conditions in many areas. Few studies have considered the interactive effects of higher CO2, temperature and drought on plant growth and physiology. We grew canola (Brassica napus cv. 45H72) plants under lower (22/18°C) and higher (28/24°C) temperature regimes in controlled-environment chambers at ambient (370 μmol mol−1) and elevated (740 μmol mol−1) CO2 levels. One half of the plants were watered to field capacity and the other half at wilting point. In three separate experiments, we determined growth, various physiological parameters and content of abscisic acid (ABA), indole-3-acetic acid and ethylene. Drought-stressed plants grown under higher temperature at ambient CO2 had decreased stem height and diameter, leaf number and area, dry matter, leaf area ratio, shoot/root weight ratio, net CO2 assimilation and chlorophyll fluorescence. However, these plants had increased specific leaf weight, leaf weight ratio and chlorophyll concentration. Elevated CO2 generally had the opposite effect, and partially reversed the inhibitory effects of higher temperature and drought on leaf dry weight accumulation. This study showed that higher temperature and drought inhibit many processes but elevated CO2 partially mitigate some adverse effects. As expected, drought stress increased ABA but higher temperature inhibited the ability of plants to produce ABA in response to drought. [ABSTRACT FROM AUTHOR]