Sl-IAA27 regulates strigolactone biosynthesis and mycorrhization in tomato (var. MicroTom)

- Root colonization by arbuscular mycorrhizal (AM) fungi is a complex and finely tuned process. Previous studies have shown that, among other plant hormones, auxin plays a role in this process but the specific involvement of Aux/IAAs, the key regulators of auxin responses, is still unknown. -In this study, we addressed the role of the tomato Sl-IAA27 during AM symbiosis by using Sl-IAA27-RNAi and pSL-IAA27::GUS stable tomato lines. - The data show that Sl-IAA27 expression is up-regulated by the AM fungus and that silencing of Sl-IAA27 has a negative impact on AM colonization. Sl-IAA27-silencing resulted in down-regulation of three genes involved in strigolactone synthesis, NSP1, D27 and MAX1, and treatment of Sl-IAA27-silenced plants with the strigolactone analog GR24 complemented their mycorrhizal defect phenotype. - Overall, the study identified an Aux/IAA gene as a new component of the signaling pathway controlling AM fungal colonization in tomato. This gene is proposed to control strigolactone biosynthesis via the regulation of NSP1

The impact of domestication and crop improvement on arbuscular mycorrhizal symbiosis in cereals: insights from genetics and genomics

The cereals (rice, maize, wheat, sorghum and the millets) provide over 50% of the world’s caloric intake, a value that rises to >80% in developing countries. Since domestication, cereals have been under artificial selection, largely directed towards higher yield. Throughout this process, cereals have maintained their capacity to interact with arbuscular mycorrhizal (AM) fungi, beneficial symbionts that associate with the roots of most terrestrial plants. It has been hypothesized that the shift from the wild to cultivation, and above all the last ~50 years of intensive breeding for high-input farming systems, has reduced the capacity of the major cereal crops to gain full benefit from AM interactions. Recent studies have shed further light on the molecular basis of establishment and functioning of AM symbiosis in cereals, providing insight into where the breeding process might have had an impact. Classic phytohormones, targets of artificial selection during the generation of Green Revolution semi-dwarf varieties, have emerged to be important regulators of AM symbiosis. Although there is still much to be learned about the mechanistic basis of variation in symbiotic outcome, these advances are providing an insight into the role of arbuscular mycorrhiza in agronomic systems

Akzent und Kolon. Zu einer prosodisch-metrischen Analyse der olympischen Strophen und Antistrophen Pindars

Stephen und Devines Buch Greek Prosody hat in der Schweiz und in Frankreich eine Forschergruppe auf den Plan gerufen, welche über den griechischen musikalischen Akzent arbeitet. In diesem Kontext versuche ich eine Arbeitshypothese zu verwenden, nach welcher Haupt- und Nebenakzente nicht einfach als Hoch- und Tie öne zu verstehen sind, sondern als Gesamtkonturlinie (ähnlich den chinesischen Tönen) und dass diese in Interaktion mit der Metrik (der Olympien Pindars) stehen: Die schräge Aufwärtsbewegung (kein direkter Tonwechsel) auf einer Zeiteinheit geht bei den von graphischen Akzenten abgesicherten Hauptakzenten in eine meist längere (ein oder zwei Zeiteinheiten nach Allens Regel) Abwärtsbewegung über, aber Aristoxenos und Aristoteles legen es nahe, auch eine „mese“ nach denselben (den Enkliseregeln ähnelnden) Prinzipien zwischen den Hauptakzenten zu postulieren, eine Art Akzentsandhi. Die daraus resultierende stete Auf- und Abmelodie scheint weniger mit der Opposition von langen und kurzen Silben zu interagieren als mit den grösseren metrischen Einheiten, den Metra und Kola. Wenn man diese nach Boegkhs und Irigoins Regeln aus der metrischen Kette gewinnt, dann zeichnet sich eine Tendenz der Kola in lexikalischer Synaphie ab, sich voneinander abzusetzen, indem der Gravis auf die letzte More des ersten Kolons und der Akut auf die erste More des folgenden Kolons fällt. Metra unter sich oder in Verbindung mit Kola werden umgekehrt eher durch eine Akzentbrücke verbunden. Kola in pausa verwenden beide Akzent!guren, vielleicht je nach Bedarf, um die Hierarchie einer Periode zu scha"en. Selbst wenn mehrere Parameter Sache der Interpretation bleiben, ist die wiederkehrende Struktur doch ein Argument für die Interaktion zwischen Metrum, Akzent und vielleicht Musik.Stephen’s and Devine’s book on Greek Prosody has triggered a whole movement of researchers in France and Switzerland working on musical accent. Within this group I try to apply a working hypothesis on how primary and secondary accents, not simply defined by higher and lower tunes, but close to Chinese contour moves, interact with Pindaric metrics (the Olympians): e oblique up-move (rather than an up-beat) followed by a longer down-slope according to Allen’s morae-rules can be based on graphic accent, but Aristoxenos and his teacher suggest as well a secondary „mese“-move (not unlike the enclitics) between the primary ones (an accentual sandhi). is steady up and down-!ow seems to be „in tune“ less with the opposition of short and long syllables, than with bigger units such as metron and colon. If we analyze the metrical !ow with Boegkh’s and Irigoin’s rules, there is a tendency for cola in lexical synaphy to be separated by down-slope (gravis) at the end of the first colon and up-move (acute) at the beginning of the second one. Metra between them or cola and metra seem to seek the inverse, an accentual bridge, whereas pausa uses both, perhaps in order to create a period-coherence. Even if several parameters are subject to interpretation, the recurring pattern suggests an interaction between metrics, accent, and maybe melody

Arbuscular mycorrhizal phenotyping: the dos and don'ts.

not applicable for letterCONICYT Leverhulm

The SAMI Galaxy Survey: Galaxy Interactions and Kinematic Anomalies in Abell 119

Galaxy mergers are important events that can determine the fate of a galaxy by changing its morphology, star formation activity and mass growth. Merger systems have commonly been identified from their disturbed morphologies, and we now can employ integral field spectroscopy to detect and analyze the impact of mergers on stellar kinematics as well. We visually classified galaxy morphology using deep images (µ_r = 28 mag arcsec^(-2)) taken by the Blanco 4 m telescope at the Cerro Tololo Inter-American Observatory. In this paper we investigate 63 bright (M_r < -19.3) spectroscopically selected galaxies in Abell 119, of which 53 are early type and 20 show a disturbed morphology by visual inspection. A misalignment between the major axes in the photometric image and the kinematic map is conspicuous in morphologically disturbed galaxies. Our sample is dominated by early-type galaxies, yet it shows a surprisingly tight Tully–Fisher relation except for the morphologically disturbed galaxies which show large deviations. Three out of the eight slow rotators in our sample are morphologically disturbed. The morphologically disturbed galaxies are generally more asymmetric, visually as well as kinematically. Our findings suggest that galaxy interactions, including mergers and perhaps fly-bys, play an important role in determining the orientation and magnitude of a galaxy's angular momentum

Strigolactone biosynthesis is evolutionarily conserved, regulated by phosphate starvation and contributes to resistance against phytopathogenic fungi in a moss, Physcomitrella patens

In seed plants, strigolactones (SLs) regulate architecture and induce mycorrhizal symbiosis in response to environmental cues. SLs are formed by combined activity of the carotenoid cleavage dioxygenases (CCDs) 7 and 8 from 9-cis-β-carotene, leading to carlactone that is converted by cytochromes P450 (clade 711; MAX1 in Arabidopsis) into various SLs. As Physcomitrella patens possesses CCD7 and CCD8 homologs but lacks MAX1, we investigated if PpCCD7 together with PpCCD8 form carlactone and how deletion of these enzymes influences growth and interactions with the environment. We investigated the enzymatic activity of PpCCD7 and PpCCD8 in vitro, identified the formed products by high performance liquid chromatography (HPLC) and LC-MS, and generated and analysed ΔCCD7 and ΔCCD8 mutants. We defined enzymatic activity of PpCCD7 as a stereospecific 9-cis-CCD and PpCCD8 as a carlactone synthase. ΔCCD7 and ΔCCD8 lines showed enhanced caulonema growth, which was revertible by adding the SL analogue GR24 or carlactone. Wild-type (WT) exudates induced seed germination in Orobanche ramosa. This activity was increased upon phosphate starvation and abolished in exudates of both mutants. Furthermore, both mutants showed increased susceptibility to phytopathogenic fungi. Our study reveals the deep evolutionary conservation of SL biosynthesis, SL function, and its regulation by biotic and abiotic cues.Deutsche Forschungsgemeinschaft AL892/1-4Academy of Finland 125312

Biostratigrafia a conodonti del Famenniano superiore nella sezione di La Serre Trench C, Montagne Noire (Francia)

La tesi ha avuto come oggetto l'analisi di alcuni campioni provenienti dalla sezione stratigrafica di La Serre Trench C (Montagne Noire, Francia meridionale), situata nel sud – ovest della Francia, in particolare nella porzione sud – orientale della catena montuosa delle Montagne Noire, al limite sud del Massiccio Centrale. Scopo del lavoro è quello di tentare di correlare i dati raccolti in campagna con quelli già presenti in letteratura, al fine di verificare l'applicabilità della biozonazione proposta da Spalletta et al. (2017), l'analisi permetterà inoltre di individuare la presenza di eventuale materiale rimaneggiato. Grazie allo studio dei conodonti rinvenuti è stato possibile datare i campioni al Famenniano superiore, in particolare è stato possibile attribuirli alla biozona Bispathodus ultimus di Spalletta et al. (2017); inoltre è stato verificato che nella sezione di La Serre Trench C non è presente materiale rimaneggiato di conodonti di tutto il Devoniano Superiore

Osteoporosis risk factors in HIV positive women with osteoporosis: A retrospective analysis

Multifactorial risk factors such as HIV/HCV co-infection and antiretroviral therapy (ARV) have been associated with osteoporosis in HIV+ women. We retrospectively analysed which known risk factors were associated with the diagnosis of osteoporosis, according to the WHO definition, in HIV positive women who were followed-up at the AIDS Centre of the University of Palermo, Italy between January 2011 and December 2014. Twenty-one HIV+ women with osteoporosis (13 HIV+ mono-infected and 8 HIV/HCV co-infected females) who underwent dual-energy X-ray absorptiometry (DXA) and liver stiffness assessment were included in the study. No significant differences between the HIV and HIV/HCV group were found regarding liver stiffness and lumbar/femoral osteoporosis scores. In a univariate analysis, we observed a positive linear correlation between LBD score (Lumbar Bone Density) with pre-fractures (p-value = 0.0082), smoke (p-value = 0.0008), alcohol (p-value &lt; 0.0001) and ARV exposure score (p-value = 0.0039), while there were no significant negative linear correlations. In multivariate analysis, pre-fractures, smoke and alcohol were positive predictors of LBD score, while previous antiretroviral therapy (ARV) (years) score was a negative predictor compared to others. Univariate analysis showed a positive linear correlation between FDB (Femoral Bone Density) with smoke (p-value = 0.0303) and alcohol (p-value = 0.0050), while there were no significant negative linear correlations. In multivariate analysis, alcohol was a positive predictor of FDB score compared to others, while ARV score was a negative predictor compared to others. This preliminary study suggests that other factors besides ARV score and liver fibrosis may affect the skeletal system in osteoporotic women with HIV infection. Some of these factors, such as alcohol and smoking, are modifiable. Additional research into impact on osteoporosis in HIV women with osteoporosis is required