Agronomic, breeding, and biotechnological approaches to parasitic plant management through manipulation of germination stimulant levels in agricultural soils

Botany ◽  
2011 ◽  
Vol 89 (12) ◽  
pp. 813-826 ◽  
Author(s):  
M. Fernández-Aparicio ◽  
J.H. Westwood ◽  
D. Rubiales
Keyword(s):  
Mycorrhizal Fungi ◽  
Agricultural Soils ◽  
Host Recognition ◽  
Plant Management ◽  
Parasitic Weed ◽  
Germination Stimulant ◽  
New Class ◽  
Agronomic Practices ◽  
Number Of Plant Species

A number of plant species have adapted to parasitize other plants, and some parasitic species pose severe constraints to major crops. The role of strigolactones and other metabolites present in host root exudates as germination stimulants for weedy root parasitic weed seeds has been known for the last 40 years. Recently, the ecological and developmental roles of strigolactones have been clarified by the discovery that they are a new class of plant hormone that controls shoot branching and serve as host recognition signals for mycorrhizal fungi. Parasitic plants also recognize these chemicals and use them to coordinate their life cycle with that of their host. Here we review agronomic practices that use parasitic germination stimulant production as a target for manipulation to control parasitic weeds.

scholarly journals The role of strigolactones in host specificity ofOrobancheandPhelipancheseed germination

2010 ◽  
Vol 21 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Mónica Fernández-Aparicio ◽  
Koichi Yoneyama ◽  
Diego Rubiales
Keyword(s):  
Seed Germination ◽  
Host Specificity ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Parasitic Plants ◽  
Parasitic Weed ◽  
Low Concentrations ◽  
Weedy Species ◽  
Germination Requirements

AbstractStrigolactones are apocarotenoids regulating shoot branching. They are also known to be exuded by plant roots at very low concentrations, stimulating hyphal branching of arbuscular mycorrhizal fungi and germination of root parasitic weed seeds. We show that strigolactones play a major role in host specificity ofOrobancheandPhelipanche(the broomrapes) seed germination. This observation confirms that host-derived germination stimulants are an important component determining the host specificity of these parasitic plants. Weedy broomrape species were less specialized in germination requirements than the non-weedy species except forO. cumanaandO. foetidavar.broteri. Similar results were obtained with the root exudates. Some species, such asP. aegyptiacaandO. minor, showed a broad spectrum of host specificity in terms of seed germination, which was stimulated by exudates from the majority of species tested, whereas others, such asO. cumana,O. hederaeandO. densiflora, were highly specific. Some species, such asO. minor,P. aegyptiacaandP. nana, were responsive to the three strigolactones studied, whereas others were induced by only one of them, or did not respond to them at all. The synthetic strigolactone analogue GR24, generally used as a standard for germination tests, was not effective on someOrobancheandPhelipanchespecies. Seeds of some species that did not respond to GR24 were induced to germinate in the presence of fabacyl acetate or strigol, confirming the role of strigolactones in host specificity.

Strigolactones: a new musician in the orchestra of plant hormones

Botany ◽  
2011 ◽  
Vol 89 (12) ◽  
pp. 827-840 ◽  
Author(s):  
Wouter Kohlen ◽  
Carolien Ruyter-Spira ◽  
Harro J. Bouwmeester
Keyword(s):  
Plant Development ◽  
Plant Hormones ◽  
Mycorrhizal Fungi ◽  
Physiological Role ◽  
Arbuscular Mycorrhizal ◽  
Root System Architecture ◽  
New Class ◽  
The Subject ◽  
Branching Factor

Strigolactones are known as germination stimulants for seeds of root parasitic plants of the Orobanchaceae and as the presymbiotic branching factor for arbuscular mycorrhizal fungi. They were also recently identified as a new class of plant hormones and have been the subject of many studies, leading to much advancement in our knowledge of how these molecules are involved in controlling plant development. In the first place, this concerns their role in the inhibition of shoot branching, but a number of studies have also revealed a role for strigolactones in shaping root system architecture or have suggested involvement of strigolactones in seed germination, hypocotyl elongation, and reproductive development. In all these studies, the interaction of strigolactones with other plant hormones such as auxin, abscisic acid, and ethylene is becoming clear. In this review we discuss the progress over the past 5 years in our understanding of the physiological role of strigolactones in the regulation of plant development.

Practical consensus recommendations - Current role of immune response evaluation criteria in solid tumors criteria in the management of cancer patients receiving immunotherapy

2019 ◽  
Vol 4 ◽  
pp. 21-23
Author(s):  
Purvish M. Parikh ◽  
T. P. Sahoo ◽  
Randeep Singh ◽  
Bahl Ankur ◽  
Talvar Vineet ◽  
...  
Keyword(s):  
Immune Response ◽  
Solid Tumors ◽  
Evaluation Criteria ◽  
Supporting Evidence ◽  
Response Evaluation ◽  
Consensus Recommendation ◽  
Current Role ◽  
New Class ◽  
Response Evaluation Criteria

Response evaluation criteria in solid tumors (RECIST) are a method used to evaluate and document the response to cancer treatment in solid tumors. The availability of a new class of immuneoncology drugs has resulted in the need to modify RECIST criteria methodology. The first leadership immuno-oncology network (LION) master course brought together experts in oncology and immuno-oncology. Six questions were put to the experts and their opinion, supporting evidence, and experience were discussed to arrive at a practical consensus recommendation. n this nascent field, the availability of a practical consensus recommendation developed by experts in the field is of immense value to the community oncologist and other health-care consultants.

scholarly journals Above- and belowground biodiversity jointly tighten the P cycle in agricultural grasslands

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yvonne Oelmann ◽  
Markus Lange ◽  
Sophia Leimer ◽  
Christiane Roscher ◽  
Felipe Aburto ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Biodiversity Loss ◽  
Management Intensity ◽  
Use Efficiency ◽  
Grassland Productivity ◽  
Global Biodiversity ◽  
Diverse Plant ◽  
Management Effects ◽  
P Cycle

AbstractExperiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment that more diverse plant communities were able to exploit P resources more completely than less diverse ones. In the agricultural grasslands that we studied, management effects either overruled or modified the driving role of plant diversity observed in the biodiversity experiment. Nevertheless, we show that greater above- (plants) and belowground (mycorrhizal fungi) biodiversity contributed to tightening the P cycle in agricultural grasslands, as reduced management intensity and the associated increased biodiversity fostered the exploitation of P resources. Our results demonstrate that promoting a high above- and belowground biodiversity has ecological (biodiversity protection) and economical (fertiliser savings) benefits. Such win-win situations for farmers and biodiversity are crucial to convince farmers of the benefits of biodiversity and thus counteract global biodiversity loss.

scholarly journals Impact of Integrated Agronomic Practices on Soil Fertility and Respiration on the Indo-Gangetic Plain of North India

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 402
Author(s):  
Rama Kant Dubey ◽  
Pradeep Kumar Dubey ◽  
Rajan Chaurasia ◽  
Ch Srinivasa Rao ◽  
Purushothaman Chirakkuzhyil Abhilash
Keyword(s):  
Soil Respiration ◽  
Soil Quality ◽  
Mycorrhizal Fungi ◽  
Field Experiments ◽  
Block Design ◽  
North India ◽  
Gangetic Plain ◽  
Agronomic Practices ◽  
Soil Sustainability ◽  
Indo Gangetic Plain

Global agricultural production is accountable for the emission of ~30% of greenhouse gases. Therefore, the wide-scale adoptions of low-input, soil-friendly, and resource-conserving agronomic practices are imperative for the ‘planet healthy food production’ and also for reducing the carbon emissions from agricultural soil. In this context, the present study aimed to analyze the impacts of integrated agronomic interventions i.e., the application of arbuscular mycorrhizal fungi (AMF) + reduced tillage (RT), biochar + RT, and AMF + biochar + RT, on spatiotemporal variations in soil-quality and soil-sustainability indicators, including microbial and soil respiration, in the Indo-Gangetic Plain (IGP) of North India. For this, field experiments on the above-mentioned agronomic interventions were employed using three different staple crops (Zea mays, Vigna mungo, and Brassica juncea) growing in three different agro-climatic zones of IGP (Varanasi, Sultanpur, and Gorakhpur) in a randomized block design. Periodic data collection was done to analyze the changes in physiochemical, biological, and biochemical properties of the soil, and statistical analyses were done accordingly. Irrespective of the sites, the experimental results proved that the integrated application of AMF + biochar + RT in V. mungo resulted in the highest soil organic carbon (i.e., 135% increment over the control) and microbial biomass carbon (24%), whereas the same application (i.e., AMF + biochar + RT) in Z. mays had the maximum reduction in microbial (32%) and soil (44%) respiration. On the other hand, enhanced occurrence of glomalin activity (98%) was noted in Z. mays cropping for all the sites. Significant negative correlation between soil respiration and glomalin activity under AMF + biochar + RT (−0.85), AMF + RT (−0.82), and biochar + RT (−0.62) was an indication of glomalin’s role in the reduced rate of soil respiration. The research results proved that the combined application of AMF + biochar + RT was the best practice for enhancing soil quality while reducing respiration. Therefore, the development of suitable packages of integrated agronomic practices is essential for agricultural sustainability.

scholarly journals Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski
Keyword(s):  
Raw Materials ◽  
Synthesis Method ◽  
Polymeric Materials ◽  
Original Research ◽  
Significant Group ◽  
Oh Groups ◽  
New Class ◽  
Hazardous Chemical ◽  
Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

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