The development of yellow lupin anthers depends on the relationship between jasmonic acid and indole-3-acetic acid.

The main purpose of this study was to demonstrate that the course of anther development, including post-meiotic maturation, dehiscence and senescence, is ensured by the interdependencies between jasmonic acid (JA) and indole-3-acetic acid (IAA) in yellow lupin (Lupinus luteus L.). The concentration of JA peaked during anther dehiscence when IAA level was low, whereas the inverse relationship was specific to anther senescence. Cellular and tissue localization of JA and IAA, in conjunction with broad expression profile for genes involved in biosynthesis, signalling, response, and homeostasis under different conditions, allowed to complete and define the role of studied phytohormones during late anther development, as well as predict events triggered by them. The development/degeneration of septum and anther wall cells, dehydration of epidermis, and rupture of stomium may involve JA signalling, while the formation of secondary thickening in endothecial cell walls is rather JA independent. The IAA is involved in programmed cell death (PCD)-associated processes during anther senescence but does not exclude its participation in the anther dehiscence processes, mainly related to cell disintegration and degeneration. A detailed understanding of these multistage processes, especially at the level of phytohormonal interplay, can contribute to the effective control of male fertility, potentially revolutionizing the breeding of L. luteus.

A novel somatic mutation in GNB2 provides new insights to the pathogenesis of Sturge-Weber syndrome.

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder characterized by vascular malformations affecting skin, eyes and leptomeninges of the brain, which can lead to glaucoma, seizures and intellectual disability. The discovery of a disease-causing somatic missense mutation in the GNAQ gene, encoding an alpha chain of heterotrimeric G-proteins, has initiated efforts to understand how G-proteins contribute to SWS pathogenesis. The mutation is predominantly detected in endothelial cells and is currently believed to affect downstream MAPK signalling. In this study of six Norwegian patients with classical SWS, we aimed to identify somatic mutations through deep sequencing of DNA from skin biopsies. Surprisingly, one patient was negative for the GNAQ mutation, but instead harbored a somatic mutation in GNB2 (NM_005273.3:c.232A>G, p.Lys78Glu), which encodes a beta chain of the same G-protein complex. The positions of the mutant amino acids in the G-protein are essential for complex reassembly. Therefore, failure of reassembly and continuous signalling is a likely consequence of both mutations. Ectopic expression of mutant proteins in endothelial cells revealed that expression of either mutant reduced cellular proliferation, yet regulated MAPK signalling differently, suggesting that dysregulated MAPK signalling cannot fully explain the SWS phenotype. Instead, both mutants reduced synthesis of Yes-associated protein (YAP), a transcriptional co-activator of the Hippo signalling pathway, suggesting a key role for this pathway in the vascular pathogenesis of SWS. The discovery of the GNB2 mutation sheds novel light on the pathogenesis of SWS and suggests that future research on targets of treatment should be directed towards the YAP, rather than the MAPK, signalling pathway.

Anther dehiscence is regulated by gibberellic acid in yellow lupine (Lupinus luteus L.).

BACKGROUND: Anther dehiscence resulting in the release of pollen grains is tightly regulated in a spatiotemporal manner by various factors. In yellow lupine (Lupinus luteus L.), a species that shows cleistogamy, the anthers split before the flowers open, but the course and regulation of this process are unknown. The specific control of anther development takes place via hormonal pathways, the wide action of which ensures reproductive success. In our previous research concerning flower and early pod development in yellow lupine, we showed that the lowest transcript level of LlDELLA1, a main repressor of gibberellin (GA) signalling, occurs approximately at the time of anther opening; therefore, the main purpose of this study was to precisely investigate the gibberellic acid (GA3)-dependent regulation of the anther dehiscence in this species. RESULTS: In this paper, we showed the specific changes in the yellow lupine anther structure during dehiscence, including secondary thickening in the endothecium by lignocellulosic deposition, enzymatic cell wall breakdown at the septum/stomium and cell degeneration via programmed cell death (PCD), and identified several genes widely associated with this process. The expression profile of genes varied over time, with the most intense mRNA accumulation in the phases prior to or at the time of anther opening. The transcriptional activity also revealed that these genes are highly coexpressed and regulated in a GA-dependent manner. The cellular and tissue localization of GA3 showed that these molecules are present before anther opening, mainly in septum cells, near the vascular bundle and in the endothecium, and that they are subsequently undetectable. GA3 localization strongly correlates with the transcriptional activity of genes related to GA biosynthesis and deactivation. The results also suggest that GA3 controls LlGAMYB expression via an LlMIR159-dependent pathway. CONCLUSIONS: The presented results show a clear contribution of GA3 in the control of the extensive anther dehiscence process in yellow lupine. Understanding the processes underlying pollen release at the hormonal and molecular levels is a significant aspect of controlling fertility in this economically important legume crop species and is of increasing interest to breeders.

The Influence of Proprioceptive Training with the Use of Virtual Reality on Postural Stability of Workers Working at Height.

The aim of the study was to assess the impact of proprioceptive training with the use of virtual reality (VR) on the level of postural stability of high-altitude workers. Twenty-one men working at height were randomly assigned to the experimental group (EG) with training (n = 10) and control group (CG) without training (n = 11). Path length of the displacement of the center of pressure (COP) signal and its components in the anteroposterior and medial-lateral directions were measured with use of an AccuGaitTM force plate before and after intervention (6 weeks, 2 sessions × 30 min a week). Tests were performed at two different platform heights, with or without eyes open and with or without a dual task. Two-way ANOVA revealed statistically significant interaction effects for low-high threat, eyes open-eyes closed, and single task-dual task. Post-training values of average COP length were significantly lower in the EG than before training for all analyzed parameters. Based on these results, it can be concluded that the use of proprioceptive training with use of VR can support, or even replace, traditional methods of balance training.

Gibberellin Signaling Repressor LlDELLA1 Controls the Flower and Pod Development of Yellow Lupine (Lupinus luteus L.).

Precise control of generative organ development is of great importance for the productivity of crop plants, including legumes. Gibberellins (GAs) play a key role in the regulation of flowering, and fruit setting and development. The major repressors of GA signaling are DELLA proteins. In this paper, the full-length cDNA of LlDELLA1 gene in yellow lupine (Lupinus luteus L.) was identified. Nuclear-located LlDELLA1 was clustered in a second phylogenetic group. Further analyses revealed the presence of all conserved motifs and domains required for the GA-dependent interaction with Gibberellin Insensitive Dwarf1 (GID1) receptor, and involved in the repression function of LlDELLA1. Studies on expression profiles have shown that fluctuating LlDELLA1 transcript level favors proper flower and pod development. Accumulation of LlDELLA1 mRNA slightly decreases from the flower bud stage to anther opening (dehiscence), while there is rapid increase during pollination, fertilization, as well as pod setting and early development. LlDELLA1 expression is downregulated during late pod development. The linkage of LlDELLA1 activity with cellular and tissue localization of gibberellic acid (GA3) offers a broader insight into the functioning of the GA pathway, dependent on the organ and developmental stage. Our analyses provide information that may be valuable in improving the agronomic properties of yellow lupine.

[Biosynthesis of cyclic GMP in plant cells - new insight into guanylate cyclases]. / Biosynteza cyklicznego GMP w komórkach roslinnych - nowe informacje dotyczace cyklaz guanylanowych.

Cyclic 3',5'-guanosine monophosphate (cGMP) is involved in many physiological processes in plants. Concentration of this second messenger in plant cell is determined by guanylyl cyclases (GCs) responsible for cGMP synthesis and phosphodiesterases (PDEs) involved in cGMP inactivation. First discovered plant GCs were localized in cytosol, but few years ago a new family of plasma membrane proteins with guanylyl cyclase activity was identified in Arabidopsis thaliana. These proteins belong to the family of a leucine-rich repeat receptor-like kinases (LRR-RLK) with extracellular leucine-rich repeat domain, a transmembrane-spanning domain, and an intracellular kinase domain. A novel class of guanylyl cyclases contain the GC catalytic center encapsulated within the intracellular kinase domain. These molecules are different to animal GCs in that the GC catalytic center is nested within the kinase domain. In presented paper we summarized the most recent data concerning plant guanylyl cyclases.

[The knowledge of students and teachers of selected groups about the OTC drugs containing codeine and pseudoephedrine--an alternative to "legal highs"?]. / Stan wiedzy uczniów i nauczycieli wybranych srodowisk na temat leków OTC zawierajacych kodeine i pseudoefedryne--alternatywa dla "dopalaczy"?

BACKGROUND: Currently the youth to intoxication increasingly used drugs generally available over the counter (OTC, Over-The-Counter drug) containing psychotropic substances. The knowledge on the subject among parents and teachers is inadequate. The aim of the study is to assess the knowledge of students and teachers about OTC drugs containing codeine or pseudoephedrine and their consequences on the use and popularity of these drugs. MATERIAL AND METHODS: The study was conducted from December 2014 to March 2015 of 93 respondents. In conducting the study used research tool in the form of an anonymous questionnaire consisting of 21 questions for the students and teachers of 16 questions, the questions relate knowledge of the studied group persons on the OTC drugs containing codeine or pseudoephedrine and the effects of their use. RESULTS: Among the students participating in the study, the majority of respondents are aware that using drugs containing codeine or pseudoephedrine can be addicted to them. Higher knowledge on this subject have demonstrated high school students, but less teachers. Most of the respondents had knowledge about the health effects that result from an overdose of these drugs. Among the students most frequently reported sources of knowledge about OTC drugs containing codeine or pseudoephedrine were friends and the Internet. CONCLUSIONS: The general knowledge of high school students and teachers on the effects of OTC medications containing codeine or pseudoephedrine is not sufficient. There is a need to conduct preventive and educational action aimed at increasing knowledge among youth and adults on the health effects of these drugs.

Relations between combined oral contraceptive therapy and indices of autonomic balance (baroreflex sensitivity and heart rate variability) in young healthy women.

INTRODUCTION: There are structural and functional links between autonomic nervous and endocrine systems. Derivatives of estrogens and gestagens applied in combined oral contraceptives (COC) reduce the production of endogenous sex steroids, but their effect on autonomic nervous system remains unknown. AIM: To compare indices of heart rate variability (HRV) and baroreflex sensitivity (BRS) among young healthy women taking vs. non-taking COC. MATERIAL AND METHODS: We performed a cross-sectional study in a group of 53 healthy women (age: 23 +/- 3 years, BMI: 22.3 +/- 2.8 kg/m(2)) taking COC for > or = 3 months (COC-group) and in a group of 113 healthy women (age: 24 +/- 4 years, BMI: 22.0 +/- 3.1 kg/m(2)) not taking COC for > or = 3 months (n-COC-group). All examined women were between the 4th and the 8th day of menstrual (or pill-driven) cycle lasting from 21 to 35 days. Indices of autonomic balance was assessed based on the time- and frequency- domains of heart rate variability (HRV very low (VLF), low (LF), high (HF) frequencies and total HRV spectrum). BRS was evaluated using the sequence (BRS-Seq) and the controlled breathing (BRS-CtBr) methods. RESULTS: There were no differences in: age, weight, height, measures of adiposity and fat distribution, the menstrual (or pill-driven) cycle day on the day of examination, heart rate and HRV parameters between the two studied groups (all p > 0.1). BRS-CtBr was higher among n-COC-group as compared to COC-group (20.00 +/- 6.28 versus 18.07 +/- 6.57 ms/mmHg, p < 0.05). There was a trend towards higher BRS-Seq in the n-COC-group as compared to the COC-group (19.4 7 +/- 7.85 versus 16.95 +/- 5.76 ms/mmHg, p = 0.12). In the n-COC-group, BRS-CtBr and RMSSD were inversely related to age (r = -0.23, r = -0.19, p < 0.05). In the COC-group, SDNN was inversely related to waist circumference and WHR (respectively r = -0.34 and r = -0.35, both p < 0.05). CONCLUSIONS: COC impair the reflex regulation of cardiovascular system based on baroreflex, which may indicate unfavorable influence of COC use on women health. The exact mechanism of BRS impairment caused by COC remains unknown, also in the context of the different composition of various COC. Thus, it needs to be studied further

[Gibberellins--structure, biosynthesis and deactivation in plants]. / Gibereliny--struktura, biosynteza i dezaktywacja u roslin.

Gibberellins (GA), as one of the most important phytohormones, control different aspect of plant growth and development such as seed germination, stem elongation and floral induction. Although identified more than a hundred and thirty GA, only a small number of them are biological active. Many non-bioactive GA are present in plant tissues as precursors or deactivated metabolites. Biochemical and genetic approaches have led to the recognition most of the genes that encode GA biosynthesis and deactivation enzymes, and conducted investigation has helped us to better understand GA functions in plants. Many enzymes involved in GA metabolism are multifunctional and therefore fewer enzymes than might be expected are required to created the various gibberellins structures. In this review, we summarized current knowledge on the GA biosynthesis and deactivation pathways in plants and showed precise characteristic of genes and encoding protein which are involved in gibberellins metabolism.

Influence of Nordic walking with poles with an integrated resistance shock absorber on carbohydrate and lipid metabolic indices and white blood cell subpopulations in postmenopausal women.

Background: Regular and individualised physical activities have been shown to prevent adverse changes associated with the aging process. The main purpose of this study was to evaluate changes in carbohydrate and lipid metabolism and white blood cell (WBC) subpopulations in postmenopausal women participating in Nordic walking (NW) training and to compare the use of poles with an integrated resistance shock absorber (RSA) with the use of classic poles. Materials & Methods: A total of 23 postmenopausal women participated in a 8-week programme of systematic physical activity between February and April. Before and after the training programme, somatic features and serum concentrations of 25-hydroxyvitamin D, glucose, and insulin, were assessed, as well as lipid profile and WBC count and its specific subpopulations. Results: Analysis of differences in somatic features and biochemical indices before and after training in the group of women who used RSA poles showed significant decreases in fat mass content (p < 0.05), insulin (p < 0.05), homeostatic model assessment of insulin resistance (p < 0.05), triglycerides (p < 0.05), total cholesterol (p < 0.05) and monocytes (p ≤ 0.01). In the group of women who used classic poles (NW), there was a significant decrease in WBC (p ≤ 0.01), lymphocytes (p < 0.05), monocytes (p ≤ 0.01) and granulocytes (p < 0.05). Conclusion: Increasing the training load through the use of RSA poles resulted in greater changes in carbohydrate and lipid metabolic indices compared to the use of classic NW poles. In turn, the more significant effect on WBC and its specific subpopulations count in the NW, compared to the RSA training programme, may indicate that specificity of training load is an important factor in modifying the immune system response.

The Effect of Nordic Walking Training with Poles with an Integrated Resistance Shock Absorber on the Body Balance of Women over the Age of 60.

The aim of this study was to assess the changes in the balance of healthy, elderly women as a result of Nordic walking training using of two types of poles: classic poles, and poles with an integrated resistance shock absorber. Thirty-four women completed the experiment (Age = 66.8 ± 4.1 years). They were randomly assigned into the experimental group-training with poles with an integrated resistance shock absorber-EG (n = 17), and the control active group-training with classic poles-CG (n = 17). Body balance was measured with Romberg sharpened test and using the AccuGait ™ force platform before and after an intervention lasting for 8 weeks (2 training sessions × 75 min per week). In ANOVA analysis, the Romberg sharpened test showed a statistically significant effect of "time" (F = 18.62, p < 0.001, ɳ2 = 0.37). No interaction effect or clear "time" effect was observed in the ANOVA analysis for the results of posturographic tests (p > 0.05). The lack of pre-post differences in posturographic tests indicates that further research is necessary, where, e.g., there are extended intervention times and more difficult examination tasks are performed. In the case of the Romberg test, both groups improved their results, which may indicate an improvement in perception and processing of sensory information, regardless of the type of training applied.

Microbial growth and volatile organic compound (VOC) emissions from carpet and drywall under elevated relative humidity conditions.

BACKGROUND: Microbes can grow in indoor environments if moisture is available, and we need an improved understanding of how this growth contributes to emissions of microbial volatile organic compounds (mVOCs). The goal of this study was to measure how moisture levels, building material type, collection site, and microbial species composition impact microbial growth and emissions of mVOCs. We subjected two common building materials, drywall, and carpet, to treatments with varying moisture availability and measured microbial communities and mVOC emissions. RESULTS: Fungal growth occurred in samples at >75% equilibrium relative humidity (ERH) for carpet with dust and >85% ERH for inoculated painted drywall. In addition to incubated relative humidity level, dust sample collection site (adonis p=0.001) and material type (drywall, carpet, adonis p=0.001) drove fungal and bacterial species composition. Increased relative humidity was associated with decreased microbial species diversity in samples of carpet with dust (adonis p= 0.005). Abundant volatile organic compounds (VOCs) that accounted for >1% emissions were likely released from building materials and the dust itself. However, certain mVOCs were associated with microbial growth from carpet with dust such as C10H16H+ (monoterpenes) and C2H6SH+ (dimethyl sulfide and ethanethiol). CO2 production from samples of carpet with dust at 95% ERH averaged 5.92 mg hr-1 kg-1, while the average for carpet without dust at 95% ERH was 2.55 mg hr-1 kg-1. CONCLUSION: Microbial growth and mVOC emissions occur at lower relative humidity in carpet and floor dust compared to drywall, which has important implications for human exposure. Even under elevated relative humidity conditions, the VOC emissions profile is dominated by non-microbial VOCs, although potential mVOCs may dominate odor production. Video Abstract.

Activated, Pro-Inflammatory Th1, Th17, and Memory CD4+ T Cells and B Cells Are Involved in Delayed-Type Hypersensitivity Arthritis (DTHA) Inflammation and Paw Swelling in Mice.

Delayed-type hypersensitivity arthritis (DTHA) is a recently established experimental model of rheumatoid arthritis (RA) in mice with pharmacological values. Despite an indispensable role of CD4+ T cells in inducing DTHA, a potential role for CD4+ T cell subsets is lacking. Here we have quantified CD4+ subsets during DTHA development and found that levels of activated, pro-inflammatory Th1, Th17, and memory CD4+ T cells in draining lymph nodes were increased with differential dynamic patterns after DTHA induction. Moreover, according to B-cell depletion experiments, it has been suggested that this cell type is not involved in DTHA. We show that DTHA is associated with increased levels of B cells in draining lymph nodes accompanied by increased levels of circulating IgG. Finally, using the anti-rheumatoid agents, methotrexate (MTX) and the anti-inflammatory drug dexamethasone (DEX), we show that MTX and DEX differentially suppressed DTHA-induced paw swelling and inflammation. The effects of MTX and DEX coincided with differential regulation of levels of Th1, Th17, and memory T cells as well as B cells. Our results implicate Th1, Th17, and memory T cells, together with activated B cells, to be involved and required for DTHA-induced paw swelling and inflammation.

The Effects of Cognitive Task and Change of Height on Postural Stability and Cardiovascular Stress in Workers Working at Height.

The purpose of the study was to analyze the effects of cognitive task and change of height on the postural stability and cardiovascular stress of at-height workers. The study included 32 healthy men aged 25-47. Due to the type of work performed, two groups were identified: at‒height workers, HW (n = 16), and office workers (mainly work at desk with a computer) OW (n = 16). The objective measures of postural stability (posturography) and cardiovascular stress (heart rate monitor) were evaluated for both groups at two different platform heights (ground level and 1 m above the ground) with or without cognitive task (backward counting). The increased height and the cognitive task were found to significantly affect measures of postural stability and cardiovascular stress. It was observed that in inexperienced OW employees, higher platform height and performing a cognitive task meant that posture stability significantly decreased, while cardiovascular stress and difficulties in maintaining balance increased. In HW group postural stability is less affected by distress conditions than in OW group.

The Effects of Nordic Walking With Poles With an Integrated Resistance Shock Absorber on Cognitive Abilities and Cardiopulmonary Efficiency in Postmenopausal Women.

Late adulthood is associated with atrophy of brain areas, which contribute to cognitive deterioration and increase the risk of depression. On the other hand, aerobic exercise can improve learning and memory function, ameliorate mood, and prevent neurodegenerative changes. This study demonstrates the effect of Nordic walking (NW) and NW with poles with an integrated resistance shock absorber (NW with RSA) on aerobic capacity and body composition in postmenopausal women. It also measures the brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) serum levels and determines correlations with cognitive functions and depression symptoms. These relationships with the use of NW with RSA as a new form of exercise have not been described thus far. In this study, 31 women (NW - 16, NW with RSA - 15) participated in eight weeks of training. The findings showed that only NW with RSA training caused a significant decrease in body mass and body mass index (p < 0.05). There were no significant changes in GDNF levels between groups studied. Regarding BDNF, a significant decrease (p < 0.05) in the NW group and an increase (not statistically significant) in the NW with RSA group was found. A comparative analysis of cognitive and depression outcomes and changes in BDNF and GDNF concentration showed no significant differences in the efficacy of either form of training. Training loads resulted in a significant increase in VO2max in both the NW (p < 0.01) and NW with RSA (p < 0.05) groups. This indicates an improvement in cardiopulmonary efficiency of the examined women.

The Effect of Nordic Walking Training with Poles with an Integrated Resistance Shock Absorber on the Functional Fitness of Women over the Age of 60.

Inadequate levels of physical activity among older people lead to a gradual decline in self-reliance and consequent dependence on other people. The aim of the study was to evaluate the impact of Nordic walking training with poles with an integrated resistance shock absorber on the functional fitness of older women. Forty-two women (Mage = 64.7 ± 3.15 years) were randomly assigned into the experimental group-training with poles with an integrated resistance shock absorber, EG (n = 21) and the control active group-training with classic poles, CG (n = 21). Functional fitness was measured with the Senior Fitness Test before and after an intervention lasting for 8 weeks (2 training sessions × 75 minutes per week). Two-way ANOVA revealed statistically significant interaction effects for aerobic endurance (F = 14.47, p < 0.001) and upper body strength (F = 5.98, p < 0.05), indicating greater improvement in the experimental group. Nordic walking training both with classic poles and with poles with an integrated resistance shock absorber is beneficial for older people and improves functional fitness over a short time period. However, the poles with an integrated resistance shock absorber provide additional resistance effort during marching, which causes increased muscle activation and results in improved muscle strength and aerobic endurance. Based on these results, it can be concluded that this kind of training could be applied in the complex health programs of seniors.

Comprehensive Insight into Gibberellin- and Jasmonate-Mediated Stamen Development.

In flowering plants, proper development of male generative organs is required for successful sexual reproduction. Stamen primordia arise in the third whorl of floral organs and subsequently differentiate into filaments and anthers. The early phase of stamen development, in which meiosis occurs, is followed by a late developmental phase, which consists of filament elongation coordinated with pollen maturation, anther dehiscence and finally viable pollen grain release. Stamen development and function are modulated by phytohormones, with a key role of gibberellins (GAs) and jasmonates (JAs). Long-term, extensive investigations, mainly involving GA/JA-deficient and GA/JA-response mutants, have led to a better understanding of the hormone-dependent molecular mechanisms of stamen development. In several species, the principal functions of GAs are to stimulate filament elongation through increased cell elongation and to promote anther locule opening. In the GA-dependent regulation of early stamen development, both the tapetum and developing pollen were identified as major targets. JAs mainly control the late stages of stamen development, such as filament elongation, viable pollen formation and anther dehiscence. A hierarchical relationship between GAs and JAs was recognized mainly in the control of late stamen development. By repressing DELLA proteins, GAs modulate the transcriptional activity of JA biosynthesis genes to promote JA production. A high level of JAs induces a complex of transcription factors crucial for normal stamen development.

Postural Stability and Physical Activity of Workers Working at Height.

The purpose of the study was to analyze the level of postural stability and physical activity of at-height workers. The study included 34 healthy men aged 25-43. Two groups were identified based on the type of work they performed: at-height workers (HW) ( n = 17), and office workers (OW) ( n = 17). Physical activity, including physical activity at work, sports activity, and leisure, was assessed with a Baecke questionnaire. For evaluation of postural stability, the one-leg standing test with eyes open and closed was used. The HW group had a higher rate of average physical activity at work than the OW group ( p = .000), whereas the OW group showed greater physical activity during leisure time ( p = .000). No differences were found between the groups in terms of sports activity. Postural stability analysis shows that the HW group ( p < .05) scored statistically significantly higher values in one-leg standing with eyes closed. The groups differed in terms of postural stability in favor of HW. At the same time, despite differences in particular aspects, the overall level of PA was similar. This may indicate that postural stability is rather affected by exposure to distress conditions.

Gibberellic acid affects the functioning of the flower abscission zone in Lupinus luteus via cooperation with the ethylene precursor independently of abscisic acid.

The abscission of plant organs is a phytohormone-controlled process. Our study provides new insight into the involvement of gibberellic acid (GA3) in the functioning of the flower abscission zone (AZ) in yellow lupine (Lupinus luteus L.). Physiological studies demonstrated that GA3 stimulated flower abortion. Additionally, this phytohormone was abundantly presented in the AZ cells of naturally abscised flowers, especially in vascular bundles. Interesting interactions among GA3 and other modulators of flower separation were also investigated. GA3 accumulated after treatment with the ethylene (ET) precursor 1-aminocyclopropane-1-carboxylic acid (ACC). Abscisic acid (ABA) treatment did not cause such an effect. Furthermore, the expression of the newly identified LlGA20ox1 and LlGA2ox1 genes encoding 2-oxoglutarate-dependent dioxygenases fluctuated after ACC or ABA treatment which confirmed the existence of regulatory crosstalk. GA3 appears to cooperate with the ET precursor in the regulation of AZ function in L. luteus flowers; however, the presented mechanism is ABA-independent.

De novo Transcriptome Profiling of Flowers, Flower Pedicels and Pods of Lupinus luteus (Yellow Lupine) Reveals Complex Expression Changes during Organ Abscission.

Yellow lupine (Lupinus luteus L., Taper c.), a member of the legume family (Fabaceae L.), has an enormous practical importance. Its excessive flower and pod abscission represents an economic drawback, as proper flower and seed formation and development is crucial for the plant's productivity. Generative organ detachment takes place at the basis of the pedicels, within a specialized group of cells collectively known as the abscission zone (AZ). During plant growth these cells become competent to respond to specific signals that trigger separation and lead to the abolition of cell wall adhesion. Little is known about the molecular network controlling the yellow lupine organ abscission. The aim of our study was to establish the divergences and similarities in transcriptional networks in the pods, flowers and flower pedicels abscised or maintained on the plant, and to identify genes playing key roles in generative organ abscission in yellow lupine. Based on de novo transcriptome assembly, we identified 166,473 unigenes representing 219,514 assembled unique transcripts from flowers, flower pedicels and pods undergoing abscission and from control organs. Comparison of the cDNA libraries from dropped and control organs helped in identifying 1,343, 2,933 and 1,491 differentially expressed genes (DEGs) in the flowers, flower pedicels and pods, respectively. In DEG analyses, we focused on genes involved in phytohormonal regulation, cell wall functioning and metabolic pathways. Our results indicate that auxin, ethylene and gibberellins are some of the main factors engaged in generative organ abscission. Identified 28 DEGs common for all library comparisons are involved in cell wall functioning, protein metabolism, water homeostasis and stress response. Interestingly, among the common DEGs we also found an miR169 precursor, which is the first evidence of micro RNA engaged in abscission. A KEGG pathway enrichment analysis revealed that the identified DEGs were predominantly involved in carbohydrate and amino acid metabolism, but some other pathways were also targeted. This study represents the first comprehensive transcriptome-based characterization of organ abscission in L. luteus and provides a valuable data source not only for understanding the abscission signaling pathway in yellow lupine, but also for further research aimed at improving crop yields.