How to pit weeds against parasitic plants. A simulation study with Phelipanche ramosa in arable cropping systems

AbstractPhelipanche ramosa is an obligate root-parasitic weed threatening major crops in central Europe. For its germination, it has to perceive various structurally diverging host-exuded signals, including isothiocyanates (ITCs) and strigolactones (SLs). However, the receptors involved are still uncharacterized. Here, we identified five putative SL receptors in P. ramosa, of which PrKAI2d3 is involved in seed germination stimulation. We established the high plasticity of PrKAI2d3, allowing interaction with different chemicals, including ITCs. The SL perception mechanism of PrKAI2d3 is similar to that of endogenous SLs in non-parasitic plants. We provide evidence that the PrKAI2d3 enzymatic activity confers hypersensitivity to SLs. Additionally, we demonstrated that methylbutenolide-OH binds PrKAI2d3 and stimulates P. ramosa germination with a bioactivity comparable to that of ITCs. This study highlights that P. ramosa has extended its signal perception system during evolution, a fact to be considered in the development of specific and efficient biocontrol methods.

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Analysis of soybean germination, emergence, and prediction of a possible northward expansion of the crop under climate change

10.1101/632976 ◽

2019 ◽

Author(s):

Jay Ram Lamichhane ◽

Julie Constantin ◽

Céline Schoving ◽

Pierre Maury ◽

Philippe Debaeke ◽

...

Keyword(s):

Climate Change ◽

Simulation Study ◽

Field Experiments ◽

Production Systems ◽

Cropping Systems ◽

Soil Surface ◽

High Sensitivity ◽

Future Climate Change ◽

Seedling Mortality ◽

Sowing Dates

AbstractSoybean (Glycine max (L.) Merr.) has potential to improve sustainability of agricultural production systems. A higher focus on this crop is needed to re-launch its production in the EU. A better understanding of key determinants affecting soybean establishment represents a first step to facilitate its adoption in cropping systems. To this objective, we conducted laboratory and field experiments in order to better characterize seed germination and seedling growth in relation to temperatures, water content, and soil structure. We then used these data to parametrize the SIMPLE crop emergence model and to evaluate its prediction quality, by comparing observed field germination and emergence data with the predicted ones. Finally, we performed a simulation study over the 2020-2100 period, for three sowing dates, from mid-March to mid-April, in the northern climate of France to evaluate whether future climate change will help expand soybean from Southern to Northern part of the country. Soybean germination was very fast, taking only 15 °C days to reach 50% germination at optimal conditions. The base, optimum and maximum temperatures were determined as 4, 30 and 40°C, respectively while the base water potential was −0.7 MPa, indicating a high sensitivity to water stress. The SIMPLE model well-predicted germination and emergence courses and their final rates, compared with the observed field data. The simulation study showed average emergence rate ranging from 61 to 78% with little variability among sowing dates and periods, but a high variability between years. Main causes of non-emergence were seedling mortality due to clods or soil surface crust followed by non-germination and seedling mortality due to drought, especially for mid-April sowing. These results provide a better knowledge of soybean establishment that are encouraging to introduce soybean with early sowings to diversify current cropping systems.

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A preliminary approach for modelling the effects of cropping systems on the dynamics of broomrape (Phelipanche ramosa) in interaction with the non-parasitic weed flora

Oléagineux Corps gras Lipides ◽

10.1051/ocl.2011.0360 ◽

2011 ◽

Vol 18 (1) ◽

pp. 39-45 ◽

Cited By ~ 3

Author(s):

Nathalie Colbach ◽

Nadia Abdennebi-Abdemessed ◽

Stéphanie Gibot-Leclerc

Keyword(s):

Cropping Systems ◽

Parasitic Weed ◽

Weed Flora ◽

Phelipanche Ramosa

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Culturable endophytic bacteria from Phelipanche ramosa (Orobanchaceae) seeds

Seed Science Research ◽

10.1017/s0960258520000343 ◽

2020 ◽

pp. 1-7

Author(s):

Katarzyna Durlik ◽

Paulina Żarnowiec ◽

Renata Piwowarczyk ◽

Wiesław Kaca

Keyword(s):

Endophytic Bacteria ◽

Soil Bacteria ◽

Plant Growth Promoting Rhizobacteria ◽

Parasitic Plants ◽

Bacillus Simplex ◽

Seed Conservation ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Phelipanche Ramosa ◽

Brevibacterium Frigoritolerans

Abstract Endophytic microbiomes play a beneficial role in the development and protection of plants. However, seed-borne endophytic bacteria have not yet been fully explored. Investigation of parasitic plants, whose existence depends on yet poorly understood and complicated relationships with microorganisms and hosts, is particularly crucial. Endophytic bacteria promote seed conservation and facilitate seed germination in soil. Several root holoparasites from the Orobanchaceae family are the most aggressive broomrape species, often causing serious yield losses in important crops. Parasitic plants are characterized by the production of a large number of some of the smallest seeds in the world's flora, allowing them to stay viable in the soil for several dozen years. This study's aim was to isolate and characterize the seed endophyte and surface bacteria of the most aggressive and widespread broomrape weed, Phelipanche ramosa. We isolated two endophytic bacteria from within the seeds which are closely related to Brevibacterium frigoritolerans and Bacillus simplex described as soil bacteria, highly resistant to environmental conditions, and as plant growth-promoting rhizobacteria. Moreover, we isolated three strains from the surface of non-sterile seeds; all three isolates were related to the Bacillus cereus group.

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