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Orobanche cumana Wallr., a root parasitic angiosperm, causes severe yield losses in Helianthus animus L. (sunflower) in Europe. Until now, the only effective method of controlling this parasite has been the use of resistant sunflower genotypes. Broomrape resistance is, however, poorly understood even though previous studies have revealed several defence mechanisms. The study of a susceptible (2603) and a resistant ( LR1 ) sunflower genotype in hydroponic co-culture showed that the degree of infection by broomrape is influenced by the concentration of nutrients in the growth medium. For the susceptible genotype, an increase in broomrape necrosis was observed when the nutrient concentration was increased. In the resistant genotype LR1, the rate of infection was reduced by increasing the concentration of mineral nutrients, measured as a decrease in broomrape attachments and a lack of underground stem development. When sunflowers were cultivated in full-strength medium, these findings correlated with a lower l4C incorporation in broomrape and a change in carbon allocation to host plant organs with a reinforced 'shoot apex sink strength'. Results demonstrated that in controlled conditions, the nutrient concentration directly affects sunflower resistance potential towards broomrape. Key words: broomrape, Helianthus, holoparasile, nutrition, resistance to Orobanche cumana, sunflower. L'Orobanche cumana Wallr., plante parasite racinaire, provoque de nombreux degats sur les cultures de tournesol (Helianthus annuus L.) dans toute l'Europe. Jusqu'a aujourd'hui, la seule methode de lutte efficace reste l'utilisation de genotypes resistants. Cependant, les mecanismes de resistance a l'orobanche restent encore meconnus. bien que des etudes precedentes aient demontre l'existence de plusieurs mecanismes. L'etude de genotypes de tournesol sensible (2603) et resistant ( LR1 ) en culture hydroponique a permis de mettre en evidence que la concentration du milieu de culture modifie le niveau d'infestation du tournesol par l'orobanche. Pour le genotype sensible (2603), le nombre de parasites necroses augmente avec la concentration du milieu de culture. Pour le genotype resistant (LR1), l'augmentation de la concentration du milieu de culture diminue l'inTestation en diminuanl le nombre d'orobanehes Tixees sur les racines et en limitant leur developpement ulterieur. Lorsque l'on cultive les tournesols dans le milieu non dilue, l'allocation de radiocarbone dans la plante se modifie avec tin accroissement de la force puits de l'apex caulinaire, alors que l'incorporation de [.sup.l4]C est reduite dans les orobanches. Notre etude demontre qu'en milieu controle, la concentration en nutriments influe directement sur le potentiel de resistance du tournesol a l'orobanche. Mots-cles : orobanche, Helianthus, holoparasile, nutrition, resistance a l'Orobanche cumana, tournesol., Introduction Within parasitic plants, some Orobanche species induce severe damage in several crops. Orobanche cumana Wallr. (broomrape), a root holoparasile, causes heavy yield losses in sunflower seed production in Europe, [...]

The article presents the study which investigates the description of the species Muhlenbergia Fasciculate from the genus type Poaceae or Muhlenbergia Schreber. It mentions that the genus species is discovered in Nagata land state in India, based on the survey conducted. The study has found that the specimens has leaf sheaths that is 2.1-3.0 cm long, spikelets is erect with a length of 2-3.1 mm, the basal blades has a length of 7-13 cm wide.

Given the toxicity of trace metals, their concentration, speciation and bioavailability serve to induce various plant detoxification processes, which themselves are specific to several parameters like plant species, tissue type and developmental stage. In this study, Myriophyllum alterniflorum (or alternate watermilfoil) enzyme activities (ascorbate peroxidase, catalase, glutathione peroxidase and superoxide dismutase) from in vitro cultures was measured over 27 days in response to copper (Cu) or cadmium (Cd) stress. These enzymes are unique to reactive oxygen species (ROS) scavenging (mainly hydrogen peroxide H 2 O 2 and superoxide anion O 2 - ) and moreover showed specific or unspecific activity profiles, depending on the metal concentrations used. Our results suggest a higher-priority protection of chloroplasts during the initial days of exposure to both metals. At the same time, the increased catalase activity could indicate an H 2 O 2 diffusion in peroxisome in order to protect other organelles from ROS accumulation. However, as opposed to the Cd effects, high Cu concentrations appear to induce a "limited oxidative threshold" for some antioxidant enzymes, which could suggest an ion absorption competition between Cu 2+ and Fe 2+ . In spite of an overall analysis conducted of the scavenging processes occurring in plant cells, biochemical analyses still yielded relevant indications regarding the watermilfoil strategies used for ROS management., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Surface water pollution by trace metal elements constitutes problems for both public and terrestrial/aquatic ecosystem health. Myriophyllum alterniflorum (alternate watermilfoil), an aquatic macrophyte known for bioaccumulating this type of pollutant, is an attractive species for plant biomonitoring within the scope of environmental research. The two metal elements copper (Cu) and cadmium (Cd) are considered in the present study. Cu is essential for plant development at low concentrations, while very high Cu concentrations are detrimental or even lethal to most plants. On the other hand, Cd is usually toxic even at low concentrations since it adversely affects the physiological plant functions. In order to check whether watermilfoil could be used for the in situ biomonitoring of Cu or Cd pollution in rivers, the plant biomarker sensitivity is first tested during long-term in vitro assays. Three markers specific to oxidative stress (glucose-6-phosphate dehydrogenase, malondialdehyde and α-tocopherol) are evaluated by varying the pollutant concentration levels. Given the absence of effective correlations between Cu and all biomarkers, the response profiles actually reveal a dependency between Cd concentration and malondialdehyde or α-tocopherol biomarkers. Conversely, preliminary in situ assays performed at 14 different localities demonstrate some clear correlations between all biomarkers and Cu, whereas the scarcity of Cd-contaminated rivers prevents using the statistical data. Consequently, the three indicated biomarkers appear to be effective for purposes of metal exposure analyses; moreover, the in situ approach, although preliminary, proves to be paramount in developing water biomonitoring bases., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Toxicity caused by trace metal elements in water is a major concern, leading to environmental disturbances and public health problems. The effect of cadmium on clonal macrophyte populations is poorly documented despite its high level of toxicity among aquatic organisms. Our aim here is to highlight the strong relationship existing between the physiological responses of Myriophyllum alterniflorum and the cadmium level over a long exposure period. Nine potential biomarkers of cadmium stress are tested, with three of them appearing to be highly sensitive: free proline, Hsp70, and malondialdehyde. Long-term follow-up analysis after metal exposure (27 days) also proves to be quite beneficial by providing a detailed overview of ecotoxicological events that is more complete and extensive than data recordings conducted over a few days. Taken together, these results support our initial hypothesis that leads to recommending biomarker analyses over at least 2 weeks of metal exposure.

This review presents the state of knowledge on the medicinal potential of bacteria associated with lichens. In fact, besides the classical symbiotic partners (photobiont and mycobiont) forming the lichen thallus, associated bacteria have been recently described as a third partner. Various studies demonstrated the diversity of these communities with a predominance of Alphaproteobacteria. Bacterial groups more relevant for secondary metabolite synthesis have also been revealed. This article summarizes studies reporting the abilities of these communities to produce metabolites with relevant bioactivities. The biotechnological interest of these bacteria for drug discovery is highlighted regarding the production of compounds with therapeutic potential. Special focus is given to the synthesis of the most promising compound, uncialamycin, a potent enediyne isolated from a Streptomyces sp. associated with Cladonia uncialis., (Georg Thieme Verlag KG Stuttgart · New York.)

Penicillium camemberti is a technologically relevant fungus used to manufacture mold-ripened cheeses. This fungal species produces many volatile organic compounds (VOCs) including ammonia, methyl-ketones, alcohols and esters. Although it is now well known that VOCs can act as signaling molecules, nothing is known about their involvement in P. camemberti lifecycle. In this study, spore germination was shown to be self-regulated by quorum sensing in P. camemberti. This phenomenon, also called "crowding effect", is population-dependent (i.e. observed at high population densities). After determining the volatile nature of the compounds involved in this process, 1-octanol was identified as the main compound produced at high-spore density using GC-MS. Its inhibitory effect was confirmed in vitro and 3 mM 1-octanol totally inhibited spore germination while 100 μM only transiently inhibited spore germination. This is the first time that self-inhibition of spore germination is demonstrated in P. camemberti. The obtained results provide interesting perspectives for better control of mold-ripened cheese processes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Proline plays an important role in plant response to various environmental stresses. However, its involvement in mitigation of heavy metal stress in plants remains elusive. In this study, we examined the effectiveness of exogenous proline (10 and 20 mM) in alleviating cadmium induced inhibitory effects in young olive plants (Olea europaea L. cv. Chemlali) exposed to two Cd levels (10 and 30 mg CdCl2 kg(-1) soil). The Cd treatment induced substantial accumulation of Cd in both root and leaf tissues and a decrease in gas exchange, photosynthetic pigments contents, uptake of essential elements (Ca, Mg and K) and plant biomass. Furthermore, an elevation of antioxidant enzymes activities (superoxide dismutase, catalase, glutathione peroxydase) and proline content in association with relatively high amounts of hydrogen peroxide, thiobarbituric acid reactive substances and electrolyte leakage were observed. Interestingly, the application of exogenous proline alleviated the oxidative damage induced by Cd accumulation. In fact, Cd-stressed olive plants treated with proline showed an increase of antioxidant enzymes activities, photosynthetic activity, nutritional status, plant growth and oil content of olive fruit. Generally, it seems that proline supplementation alleviated the deleterious effects of young olive plants exposed to Cd stress., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Nowadays, submersed aquatic macrophytes play a key role in stream ecology and they are often used as biomonitors of freshwater quality. So, these plants appear as natural candidates to stream rehabilitation experiments. Among them, the stream macrophyte Myriophyllum alterniflorum is used recently as biomonitor and is potentially useful for the restoration of heavy-metal contaminated localities. The best way to obtain a mass production of watermilfoil plants is micropropagation. We developed in vitro culture of M. alterniflorum and the effects of five media on the plant development were assessed. Five morphological and four physiological endpoints were examined leading to the recommendation of the Murashige and Skoog medium for ecotoxicological studies on chlorophyllous parts, and of the Gaudet medium for root cytotoxicity and phytoremediation studies. Micropropagated clones were acclimatized in a synthetic medium and in situ reintroduction was performed efficiently. This is the first report of micropropagated plants transplantation in streams. The successful establishment of watermilfoil beds even in polluted areas strongly suggested that ecological restoration using micropropagated watermilfoil is a promising biotechnology for phytoremediation and rehabilitation of degraded areas. Moreover, high bioconcentration factors evidenced that watermilfoil hyperaccumulates Cd and Cu, and could be potentially used in phytoremediation studies.

Agar substrates for in vitro culture are well adapted to plant micropropagation, but not to plant rooting and acclimatization. Conversely, paper-pulp-based substrates appear as potentially well adapted for in vitro culture and functional root production. To reinforce this hypothesis, this study compares in vitro development of nemesia on several substrates. Strong differences between nemesia roots growing in agar or in paper-pulp substrates were evidenced through scanning electron microscopy. Roots developed in agar have shorter hairs, larger rhizodermal cells, and less organized root caps than those growing on paper pulp. In conclusion, it should be noted that in this study, in vitro microporous substrates such as paper pulp lead to the production of similar root hairs to those found in greenhouse peat substrates. Consequently, if agar could be used for micropropagation, rooting, and plant acclimatization, enhancement could be achieved if rooting stage was performed on micro-porous substrates such as paper pulp.