scholarly journals Localization of planteose hydrolysis during seed germination of Orobanche minor

2021 ◽  
Author(s):  
Atsushi Okazawa ◽  
Atsusya Baba ◽  
Hikaru Okano ◽  
Tomoya Tokunaga ◽  
Tsubasa Nakaue ◽  
...  
Keyword(s):  
Seed Germination ◽  
Weed Control ◽  
Practical Method ◽  
Life Cycles ◽  
Ionization Mass ◽  
Parasitic Weed ◽  
Parasitic Weeds ◽  
Physiological Processes ◽  
Biochemical Assays ◽  
Storage Carbohydrate

Root parasitic weeds of the Orobanchaceae, such as witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.), cause serious losses in agriculture worldwide. No practical method to control these parasitic weeds has been developed to date. Understanding the characteristic physiological processes in the life cycles of root parasitic weeds is particularly important to identify specific targets for growth modulators. In our previous study, planteose metabolism was revealed to be activated soon after the perception of strigolactones in germinating seeds of O. minor. Nojirimycin inhibited planteose metabolism and impeded seed germination of O. minor, indicating that planteose metabolism is a possible target for root parasitic weed control. In the present study, we investigated the distribution of planteose in dry seeds of O. minor by matrix-assisted laser desorption/ionization—mass spectrometry imaging. Planteose was detected in tissues surrounding—but not within—the embryo, supporting its suggested role as a storage carbohydrate. Biochemical assays and molecular characterization of an α-galactosidase family member, OmAGAL2, indicated the enzyme is involved in planteose hydrolysis in the apoplast around the embryo after the perception of strigolactones to provide the embryo with essential hexoses for germination. These results indicated that OmAGAL2 is a potential molecular target for root parasitic weed control.

scholarly journals Synthesis and Evaluation of New Halogenated GR24 Analogs as Germination Promotors for Orobanche cumana

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuchao Chen ◽  
Yi Kuang ◽  
Liyang Shi ◽  
Xing Wang ◽  
Haoyu Fu ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Life Cycle ◽  
Seed Germination ◽  
Binding Affinity ◽  
Weed Control ◽  
Host Plants ◽  
Control Methods ◽  
Parasitic Weeds ◽  
Orobanche Cumana ◽  
Promising Agent

Orobanche and Striga are parasitic weeds extremely well adapted to the life cycle of their host plants. They cannot be eliminated by conventional weed control methods. Suicidal germination induced by strigolactones (SLs) analogs is an option to control these weeds. Here, we reported two new halogenated (+)-GR24 analogs, named 7-bromo-GR24 (7BrGR24) and 7-fluoro-GR24 (7FGR24), which were synthesized using commercially available materials following simple steps. Both compounds strongly promoted seed germination of Orobanche cumana. Their EC50 values of 2.3±0.28×10−8M (7BrGR24) and 0.97±0.29×10−8M (7FGR24) were 3- and 5-fold lower, respectively, than those of (+)-GR24 and rac-GR24 (EC50=5.1±1.32–5.3±1.44×10−8; p<0.05). The 7FGR24 was the strongest seed germination promoter tested, with a stimulation percentage of 62.0±9.1% at 1.0×10−8M and 90.9±3.8% at 1.0×10−6M. It showed higher binding affinity (IC50=0.189±0.012μM) for the SL receptor ShHTL7 than (+)-GR24 (IC50=0.248±0.032μM), rac-GR24 (IC50=0.319±0.032μM), and 7BrGR24 (IC50=0.521±0.087μM). Molecular docking experiments indicated that the binding affinity of both halogenated analogs to the strigolactone receptor OsD14 was similar to that of (+)-GR24. Our results indicate that 7FGR24 is a promising agent for the control of parasitic weeds.

Systems of Weed Control for Peanuts

Weed Science ◽  
1973 ◽  
Vol 21 (3) ◽  
pp. 176-180 ◽  
Author(s):  
E. W. Hauser ◽  
S. R. Cecil ◽  
C. C. Dowler
Keyword(s):  
Seed Germination ◽  
Weed Control ◽  
Soil Types ◽  
Average Weight ◽  
Clay Loam ◽  
Sandy Clay Loam ◽  
Effective System ◽  
Economical System ◽  
Grade Average

Systems of weed control composed of (a) herbicides only, (b) herbicides plus cultivation, or (c) cultivation only were devised. The most effective systems, involving herbicide sequences plus one “non-dirting” layby cultivation, controlled twelve troublesome species of weeds with acceptable yields of peanuts (Arachis hypogaea L.). On Greenville sandy clay loam, a particularly effective and economical system of weed control consisted of (a) N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine (benefin) used as a preplanting incorporated treatment, then (b) S-propyl dipropylthiocarbamate (vernolate) either incorporated into the soil before planting or injected at planting, and finally, (c) a layby cultivation 5 to 6 weeks after planting. A similarly effective system on Tifton loamy sand involved vernolate injected at planting, 2-sec-butyl-4,6-dinitrophenol (dinoseb) at “cracking”, and 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) as a postemergence treatment followed by the layby cultivation. The “non-dirting” layby cultivation, averaged over both years and herbicide sequences, significantly increased yields of peanuts on both soil types. None of the systems of weed control caused consistent differences in market grade, average weight per seed, germination, or organoleptic quality of the peanuts.

scholarly journals Arabidopsis SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2 inhibit WRKY75 function in abscisic acid-mediated leaf senescence and seed germination

2021 ◽  
Author(s):  
Haiyan Zhang ◽  
Liping Zhang ◽  
Yunrui Ji ◽  
Yifen Jing ◽  
Lanxin Li ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Leaf Senescence ◽  
Chromatin Immunoprecipitation ◽  
Sigma Factor ◽  
Dependent Manner ◽  
Negative Regulators ◽  
Factor Binding ◽  
Physiological Processes ◽  
Increased Sensitivity

Abstract The plant-specific VQ gene family participates in diverse physiological processes but little information is available on their role in leaf senescence. Here, we show that the VQ motif-containing proteins, Arabidopsis SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2 are negative regulators of abscisic acid (ABA)-mediated leaf senescence. Loss of SIB1 and SIB2 function resulted in increased sensitivity of ABA-induced leaf senescence. In contrast, overexpression of SIB1 significantly delayed this process. Moreover, biochemical studies revealed that SIBs interact with WRKY75 transcription factor. Loss of WRKY75 function decreased sensitivity to ABA-induced leaf senescence, while overexpression of WRKY75 significantly accelerated this process. Chromatin immunoprecipitation assays revealed that WRKY75 directly binds to the promoters of GOLDEN 2-LIKE1(GLK1) and GLK2, to repress their expression. SIBs repress the transcriptional function of WRKY75 and negatively regulate ABA-induced leaf senescence in a WRKY75-dependent manner. In contrast, WRKY75 positively modulates ABA-mediated leaf senescence in a GLK-dependent manner. In addition, SIBs inhibit WRKY75 function in ABA-mediated seed germination. These results demonstrate that SIBs can form a complex with WRKY75 to regulate ABA-mediated leaf senescence and seed germination.

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.

Survey Results on Environmental Issues and Weed Science Research Priorities within the Corn Belt

1993 ◽  
Vol 7 (3) ◽  
pp. 763-770 ◽  
Author(s):  
Edward W. Stoller ◽  
Loyd M. Wax ◽  
David M. Alm
Keyword(s):  
Weed Control ◽  
Control Strategies ◽  
Research Priorities ◽  
Environmental Issues ◽  
Science Research ◽  
Life Cycles ◽  
Cultural Control ◽  
Corn Belt ◽  
Weed Species ◽  
Weed Science

A survey determined the views of individuals in seven groups comprising the weed science community in the corn belt (primarily in Illinois) for importance of 8 environmental and 14 crop production issues and 16 weed species in setting weed science research priorities for the next 3 to 5 yr. The survey also considered if funding of research to solve these environmental and production issues should be from the private or public sector. Velvetleaf, foxtail species, and common lambsquarters were considered the top three weed species by all respondents, and each of these weeds was among the five most important weeds within each of the seven survey groups. Improving ground and surface water quality were the foremost environmental issues for all respondents, but soybean growers listed herbicide carryover as their top environmental concern. Reducing herbicide residues in food and developing sustainable practices were given low preference by all groups. Sustainable growers rated reducing herbicide carryover and minimizing applicator exposure as their lowest priorities. Among all respondents, the top three production issues were improved weed control in conservation tillage, more economical weed control, and improved integrated control strategies. Studying the biology/life cycles of weeds was the third highest production priority of University and U.S. Department of Agriculture (USDA) weed scientists, but was the last choice when averaged over the aggregate survey group. Developing strategies for resistant weeds and herbicide-resistant crops were chemical dealers top two priorities. Industry representatives gave the former subject their highest rating and the latter their lowest rating. Crop consultants seemed to want decision aids, as they chose assessing weed loss/thresholds and developing weed control/economic models among their top three production issues. Both corn and soybean growers desired more economical weed control as a first choice, while sustainable growers wanted improved cultural control strategies. Corn and soybean growers ranked developing new herbicides among their top three choices, but this issue was the lowest choice of the sustainable growers. University, USDA, and industrial weed scientists suggested that their own organizations conduct the research on their highest priorities issues.

Pollutant-induced effects on immunological and physiological interactions in aquatic host–trematode systems: implications for parasite transmission

2006 ◽  
Vol 80 (2) ◽  
pp. 137-149 ◽  
Author(s):  
N.J. Morley ◽  
J.W. Lewis ◽  
D. Hoole
Keyword(s):  
Life Cycles ◽  
Economic Importance ◽  
Parasite Transmission ◽  
Combined Stress ◽  
Complex Life Cycles ◽  
Physiological Processes ◽  
Digenetic Trematodes ◽  
Functional Biology ◽  
Parasite Populations ◽  
Pathogenic Effects

AbstractUnder conditions of pollution both host and parasite are susceptible to the pathogenic effects of toxicants, which in turn may result in detrimental changes to their immunological and physiological processes. Digenetic trematodes, which encompass species of both medical and economic importance, possess complex life cycles and are common parasites of both vertebrates and molluscs. The combined stress induced by pollution and parasitism influences the physiology of the host which can have implications not only on host survival but also on the functional biology of resident parasite populations. The present paper reviews the effects of pollutants on the immunology and physiology in both vertebrate and molluscan host–trematode systems and the implications for parasite transmission.

Seed germination and seedling emergence of threehorn bedstraw (Galium tricornutum)

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 867-872 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
Gurjeet Gill ◽  
Christopher Preston
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Low Temperature ◽  
Osmotic Stress ◽  
Weed Control ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Control Programs ◽  
Field Crops ◽  
Winter Crops

Threehorn bedstraw is an important dicotyledonous weed of winter crops in southern Australia, which can be difficult to control in some field crops. Knowledge of the germination ecology of this weed would facilitate development of effective weed control programs. Seed germination in the laboratory was greater for seeds that after-ripened while buried in the soil relative to those that after-ripened on the soil surface. The timing of greatest seed germination in the laboratory was found to coincide with the period of low temperature in the field. Seed germination of threehorn bedstraw was moderately sensitive to salt stress but moderately tolerant to osmotic stress. Seeds of threehorn bedstraw germinated over a broad range of pH from 4 to 10. No seedlings emerged from seeds placed on the soil surface. Maximum seedling emergence occurred at depths of 1 to 2 cm (89 to 91%) and declined at greater depths.

scholarly journals Rice farming components for biological weed control in transplanted rice: Perspective on weedy rice management

Weed Science ◽  
2021 ◽  
pp. 1-16
Author(s):  
Kathiresan Ramanathan ◽  
Vishnudevi Sangeeviraman
Keyword(s):  
Oryza Sativa ◽  
Seed Germination ◽  
Weed Control ◽  
Grass Carp ◽  
Poultry Manure ◽  
Ctenopharyngodon Idella ◽  
Biological Weed Control ◽  
Weedy Rice ◽  
Rice Seed ◽  
Poultry Birds

Abstract Farming elements other than the crop, when integrated in the system, are supplementary with multifold uses that include weed and pest management. The elements such as fish and poultry birds are integrated with transplanted wetland rice (Oryza sativa L.) for ensuring livelihood and nutritional security and sustainability of the system. The integrated animal components such as poultry birds and fishes also supplement the system with weed control. The role and efficacy of these animal components as tools for managing weedy rice (Oryza sativa L.) were explored as weedy rice infestation is increasing. This threat of weedy rice is due to scarcity of water resulting poor water management and improper field leveling. Grass carp (Ctenopharyngodon idella val.)caused highest reduction in weedy rice biomass of 28 % within 24h under laboratory conditions. Polyculture of grass carp, mrigal (Cirrhinus mrigala Ham.), and silver carp (Hypophthalmichthys molitrix val.) reduced the biomass of weedy rice by 21 % within 24 h. In laboratory studies, poultry manure at 5 % concentrationreduced the seed germination of weedy rice 100 %at the highest concentration of 5 %, compared to rice seed germination 91 %. This conformedwith microplot experiments, wherein poultry manure at 15.6 g day−1resulted in weed control index of 8 % in both years. However, poultry manure at 15.6 g day−1 in combination with herbicide application resulted the highest control indices of weedy rice with 52 % in 2017 and 2018.Integrating fish and poultry with preemergence application of oxyfluorfen (0.25 kg ha−1)resulted in highest weed control index and grain yield, in field experiments.

scholarly journals Gasotransmitter H2S accelerates seed germination via activating AOX mediated cyanide-resistant respiration pathway

2021 ◽  
Author(s):  
Huihui Fang ◽  
Ruihan Liu ◽  
Zhenyuan Yu ◽  
Gang Wu ◽  
Yan xi Pei
Keyword(s):  
Seed Germination ◽  
Alternative Oxidase ◽  
Reducing Power ◽  
Underlying Mechanism ◽  
Terminal Oxidase ◽  
Post Translational Modification ◽  
Physiological Processes ◽  
Activity Of Enzymes ◽  
Cyanide Metabolism ◽  
Cyanide Resistant Respiration

Hydrogen sulfide (H2S) has been witnessed as a crucial gasotransmitter involving in various physiological processes in plants. H2S signaling has been reported to involve in regulating seed germination, but the underlying mechanism remains poorly understood. Here, we found that endogenous H2S production was activated in germinating Arabidopsis seeds, correlating with upregulated both the transcription and the activity of enzymes (LCD and DES1) responsible for H2S production. Moreover, NaHS (the H2S donor) fumigation significantly accelerated seed germination, while H2S-generation defective (lcd/des1) seeds exhibited decreased germination speed. Further results indicated that the alternative oxidase (AOX), a cyanide-insensitive terminal oxidase, can be stimulated by imbibition, and the expression of AOX genes was provoked lag behind H2S production during germination. Additionally, exogenous H2S fumigation significantly reinforced imbibition induced enhancement of AOX1A expression, and mediated post-translational modification to keep AOX in its reduced and active state, which mainly involved H2S induced increase of the GSH/GSSG ratio and the cell reducing power. Consequently, H2S signaling acts as a trigger to induce AOX mediated cyanide-resistant respiration to accelerate seed germination. Our study correlates H2S signaling to cyanide metabolism, which also participates in endogenous H2S generation, providing evidence for more extensive studies of H2S signaling.

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