Home |
Search |
Today's Posts |
#1
|
|||
|
|||
[IBC] Glucose
Theo: Are you sure the article was about glucose and not glomalin? I will copy
below parts of an article I published in my March 2003 newsletter. The original article was from the September 2002 issue of Agricultural Research magazine. Until its discovery in 1996 this soil "super glue" was mistaken for an unidentifiable constituent of soil organic matter. Rather, it permeates organic matter, binding it to silt, sand, and clay particles. Not only does glomalin contain 30 to 40 percent carbon, but it also forms clumps of soil granules called aggregates. These add structure to soil and keep other stored soil carbon from escaping. As a glycoprotein, glomalin stores carbon in both its protein and carbohydrate (glucose or sugar) subunits. Dr. Sarah Wright, who discovered this substance, thinks the glomalin molecule is a clump of small glycoproteins with iron and other ions attached. She found that glomalin contains from 1 to 9 percent tightly bound iron. Glomalin is causing a complete reexamination of what makes up soil organic matter. A study showed that glomalin accounts for 27 percent of the carbon in soil and is a major component of soil organic matter. Glomalin weighs 2 to 24 times more than humic acid, a product of decaying plants that up to now was thought to be the main contributor to soil carbon. But humic acid contributes only about 8 percent of the carbon. Another team recently used carbon dating to estimate that glomalin lasts 7 to 42 years, depending on conditions. Interestingly, the article noted that a current study in Costa Rica uses glomalin levels and root growth to measure the amount of carbon stored in soils beneath tropical forests. Researchers are finding lower levels of glomalin than expected and a much shorter lifespan. "We think it's because of the higher temperatures and moisture in tropical soils." These factors break down glomalin. (To me, this means that the extra heat our soils endure in our containerized bonsai might cause the same effects.) It is glomalin that gives soil its tilth—a subtle texture that enables experienced farmers and gardeners to judge great soil by feeling the smooth granules as they flow through their fingers. Arbuscular mycorrhizal fungi, found living on plant roots around the world, appear to be the only producers of glomalin. Glomalin was named after Glomales, the taxonomic order that arbuscular mycorrhizal fungi belong to. The fungi use carbon from the plant to grow and make glomalin. In return, the fungi's hairlike filaments, called hyphae, extend the reach of plant roots. Hyphae function as pipes to funnel more water and nutrients—particularly phosphorus—to the plants. "We've seen glomalin on the outside of the hyphae, and we believe this is how the hyphae seal themselves so they can carry water and nutrients. It may also be what gives them the rigidity they need to span the air spaces between soil particles." As a plant grows, the fungi move down the root and form new hyphae to colonize the growing roots. When hyphae higher up on the roots stop transporting nutrients, their protective glomalin sloughs off into the soil. There it attaches to particles of minerals (sand, silt, and clay) and organic matter, forming clumps. This type of soil structure is stable enough to resist wind and water erosion, but porous enough to let air, water, and roots move through it. It also harbors more beneficial microbes, holds more water, and helps the soil surface resist crusting. Scientists think hyphae have a lifespan of days to weeks. The much longer lifespan of glomalin suggests that the current technique of weighing hyphae samples to estimate fungal carbon storage grossly underestimates the amount of soil carbon stored. In fact, Wright and colleagues found that glomalin contributes much more nitrogen and carbon to the soil than do hyphae or other soil microbes. There was much more to the article, but the list limits length of responses, so that will do for now. Alan Walker, Lake Charles, LA, USA http://LCBSBonsai.org http://bonsai-bci.com =============================== Theo wrote: HI In the italian Issue of Bonsai and news is published a topic about the use of glucose to enhance the roots growth. I do not know what it deals exactly about. any feed back from others review / personal experience? Theo ************************************************** ****************************** ++++Sponsored, in part, by Mike Page ++++ ************************************************** ****************************** -- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ -- +++++ Questions? Help? e-mail +++++ |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
something about ADP-Glucose Pyrophosphorylase Assay | Plant Science | |||
[IBC] Glucose and stuff | Bonsai | |||
Glucose | Bonsai | |||
[IBC] FW: [IBC] Mastering Technique (Was [IBC] proposal) | Bonsai | |||
[IBC] To: IBC Enforcer (was: [IBC] Juniper Bonsai life expectancy?) | Bonsai |