Do Leaf Bacteria Fertilize Plants?

The “Inside” Story? An article in Science magazine (see Ref. 1 below) reports evidence supporting the hypothesis that leaf-dwelling, nitrogen-fixing bacteria may provide host plants with significant amounts of nitrogen. In the past, we briefly explored the microbial phyllosphere, that is, the microbes – including nitrogen-fixing cyanobacteria – that dwell…

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Life in the Rhizosphere

The Rhizosphere Roots are leaky. That is, some of the sugars transported from the leaves down to the roots may diffuse into the narrow area of soil near the roots. Plant roots also secrete polysaccharides and glycoproteins (sometimes called mucilage) and other organic compounds. Thus, to soil-dwelling microorganisms, plant roots…

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Plant “Social Networks” – Is This Why Companion Planting & Inter-Cropping Work?

Plant Networking Many neighboring plants may be interconnected by an underground fungal network known as mycorrhizae. (See a previous post on the subject.) These soil fungi, called arbuscular mycorrhizal fungi (AMF), are found in virtually all terrestrial ecosystems, and they form symbiotic relationships with a wide variety of plants. The…

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The Wood-Wide-Web: Are Plants Inter-Connected by a Subterranean Fungal Network?

Mushrooms are the visible manifestations (sexual organs, actually) of microscopic, soil-dwelling fungi that form mutually-beneficial partnerships with plants. Since these filamentous fungi interact with the roots of plants, such symbiotic relationships are called mycorrhizae, literally “fungus root”. Fossil evidence supports the idea that these plant-fungal partnerships are as old as…

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Life in the Phyllosphere: What Microbes Commonly Dwell on the Surface of Leaves?

Leaf Surfaces = Microbial Habitats Imagine all the leaves of all the plants currently living on planet Earth. Now, add up all the surface areas of all of those leaves. And your answer is?… No idea?…. Luckily, some microbiologists have made an estimate, and it’s an astounding number. According to…

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