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Acclimation of root growth is vital for plants to survive salt stress. Halophytes are great examples of plants that thrive under high salt concentrations 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 root transcriptomic analysis to identify differences in gene regulatory networks underlying their physiological responses. Primary root growth of S. parvula is less sensitive to salt compared with Arabidopsis. The root transcriptomic analysis of S. parvula revealed the induction of sugar transporters and genes regulating cell expansion and suberization under salt stress. 14C-labelled carbon partitioning analyses consistently showed that S. parvula had a higher incorporation rate of soluble sugars in roots under salt stress compared to Arabidopsis. Further physiological investigation revealed that S. parvula roots do not show a halotropic response and maintain root cell expansion and enhanced suberization even under severe salt stress. In summary, our study demonstrates that 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. more...

The efficacy of several antifungal compounds, chosen among salts, oils, plant extracts, and of the hyperparasitic fungus Ampelomyces quisqualis , were tested in seven glasshouse trials against powdery mildew on roses ( Sphaerotheca pannosa var. rosae ) in Sanremo (N. Italy). In the presence of a high disease incidence (55% of untreated leaves infected in six out of seven trials), all the antifungal compounds and the biocontrol agent A. quisqualis , applied individually, provided satisfactory control of powdery mildew. Most treatments were as efficient as the fungicide dodemorph, which, sprayed at weekly intervals, provided a 75% average efficacy throughout the trials. Among the test compounds, KH 2 PO 2 , at 0.5 and 1%, offered good and consistent disease control, NaHCO 3 , at 0.5%, showed a satisfactory level of activity, while at 1% it was phytotoxic. Wine vinegar, applied at 5 and 10%, gave good control, but acetic acid was phytotoxic. JMS Stylet oil, the canola oil, Synertrol and neem extract provided satisfactory disease control. Fatty acids formulated as potassium salts significantly and consistently reduced powdery mildew severity, but caused some phytotoxicity. Milsana, a concentrated extract from leaves of Reynoutria sachalinensis , only partially controlled powdery mildew. Several strategies based on the rotation of different antifungal compounds, with or without the application of dodemorph, provided very good, consistent disease control. The potential of some of the antifungal compounds and of the biocontrol fungus A. quisqualis against rose powdery mildew is discussed. more...

Background Long Term Care Facilities (LTCFs) play a key role in guaranteeing care to patients in developed countries. Many patients, mostly elderly, access LTCFs at some time in their lives, and their healthcare pathways often require them to move back and forth between hospital and outpatient settings. These patterns bring about new challenges regarding infection control, especially healthcare associated infections. Methods A point prevalence study was conducted in 23 Italian LTCFs, to identify colonization in patients with urinary catheter (>24 hours). Species identification, susceptibility tests and extended spectrum beta lactamase (ESBL) production screenings were performed using Vitek 2 System. Enterobacteria identified by Vitek 2 System as ESBL-producers or suspected AmpC hyperproducers on the basis of cephamycin resistance, were sent to a research laboratory where they underwent a double-disk synergy test. Finally, ESBL-producers were screened for bla resistance genes by PCR assay. Results 211 patients with catheter were screened, 185 out of 211 patients showed positive samples for the presence of Enterobacteriaceae, 114 of these 185 patients were colonized by extended spectrum cephalosporins resistant microorganisms. We identified a total of 257 Gram negative pathogens, of which 51.8% (133/257) were extended spectrum cephalosporins resistant. 7 out of 133 cephamycin not susceptible strains proved to be AmpC-type beta-lactamases and 125/133 ESBL-producers; 1 was not further characterized. 43 out of 257 (16.7%) E. coli, 37/257 (14.4%) P. mirabilis, 20/257 (7.8%), P. stuartii, 14/257 (5.4%) M. morganii, 7/257 (2.7%), K. pneumoniae, 4/257 (1.6%) C. koseri proved to be overall ESBL-producers by double-disk synergy test. Third and fourth generation cephalosporin resistant P. mirabilis, P. stuartii and M. morganii strains mainly harboured a blaTEM gene (95.9%), while 89.1% of E. coli were positive for the blaCTX-M determinant by PCR and sequencing. Patients with decubitus had a higher risk of colonization by at least one resistant isolate (p more...

A new enzyme, S-adenosyl-l-methionine:flavonoid 4'-O-methyltransferase (EC 2.1.1.-) (F 4'-OMT), has been purified 1 399-fold from the tissues of carnation (Dianthus caryophyllus L). The enzyme, with a molecular mass of 43-45 kDa and a pI of 4.15, specifically methylates the hydroxy substituent in 4'-position of the flavones, flavanones and isoflavones in the presence of S-adenosyl-l-methionine. A high affinity for the flavone kaempferol was observed (Km = 1.7 micro m; Vmax = 95.2 micro mol.min-1.mg-1), while other 4'-hydroxylated flavonoids proved likewise to be suitable substrates. Enzyme activity had no apparent Mg++ requirement but was inhibited by SH-group reagents. The optimum pH value for F 4'-OMT activity was found to be around neutrality. Kinetic analysis of the enzyme bi-substrate reaction indicates a Ping-Pong mechanism and excludes the formation of a ternary complex. The F 4'-OMT activity was increased, in both in vitro and in vivo carnation tissues, by the inoculation with Fusarium oxysporum f. sp. dianthi. The enzyme did not display activity towards hydroxycinnamic acid derivatives, some of which are involved, as methylated monolignols, in lignin biosynthesis; the role of this enzyme could be therefore mainly defensive, rather than structural, although its precise function still needs to be ascertained. more...

Dopo avere, in una precedente nota comparsa in questo stesso volume della Rivista, trattato in linea generale della fisiologia e della patologia dell'apparato pigmentifero melanico, gli Autori studiano particolareggiatamente nel presente lavoro i melanomi maligni insorti sulle mucose dell'estremo cefalico. Questi tumori, tutt'altro che eccezionali a livello delle fosse nasali e del cavo orale, sono alquanto meno frequenti nella congiuntiva e molto rari nei seni paranasali, nel faringe, nell'esofago, mentre non risultano descritti casi interessanti la laringe e l'orecchio medio con le cavita annesse. Istologicamente, questi tumori metanici non si differenziano da quelli a sede cutanea, mentre clinicamente sono caratterizzati (con una parziale eccezione per alcune forme congiuntivali) da una elevata malignita. Il trattamento chirurgico deve essere precoce e radicale al massimo grado, ma non puo consentire che una dilazione dell'exitus, evitabile soltanto in alcune localizzazioni congiuntivali. Un'attenzione... more...

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. C-14-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., New Phytologist, 238 (5), ISSN:0028-646X, ISSN:1469-8137 more...