The laimosphere is the

microbiological Microbiology () is the scientific study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, pro ...

ly enriched zone of

soil Soil, also commonly referred to as earth or dirt Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debri ...

that surrounds below-ground portions of plant stems; the laimosphere is analogous to the

rhizosphere The rhizosphere is the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Soil pores in the rhizosphere can contain many bacteria and other microo ...

and

spermosphere In plant science, the spermosphere is the zone in the soil surrounding a germinating seed. This is a small volume with radius perhaps 1 cm but varying with seed type, the variety of soil microorganisms, the level of soil moisture, and other f ...

. The combining form laim- from (Greek: λαιμός, "throat") denotes a connecting organ (neck) while -sphere indicates a zone of influence. Topographically, the ''laimosphere'' includes the soil around any portion of subterranean plant organs other than roots where exuded nutrients (especially sugars and amino acids) stimulate microbial activities. Subterranean

plant organ In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a ...

s with a laimosphere include

hypocotyl The hypocotyl (short for "hypocotyledonous stem", meaning "below seed leaf") is the stem of a germinating seedling, found below the cotyledons (seed leaves) and above the radicle ( root). Eudicots As the plant embryo grows at germination, it se ...

epicotyl An epicotyl is important for the beginning stages of a plant's life. It is the region of a seedling stem above the stalks of the seed leaves of an embryo plant. It grows rapidly, showing hypogeal germination, and extends the stem above the soil surf ...

s, stems, stolons,

corm A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem that serves as a storage organ that some plants use to survive winter or other adverse conditions such as summer drought and heat (perennation). The word ' ...

s, bulbs, and leaves. Propagules of soil-borne plant pathogens, whose germination is stimulated by a plant exudates in the laimosphere, can initiate hypocotyl and stem rots leading to "damping-off". Pathogens commonly found to cause such diseases are species of ''

Fusarium ''Fusarium'' is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the soil mi ...

'', ''

Phoma ''Phoma'' is a genus of common coelomycetous soil fungi. It contains many plant pathogenic species. Description Spores are colorless and unicellular. The pycnidia are black and depressed in the tissues of the host. ''Phoma'' is arbitrarily li ...

'', ''

Phytophthora ''Phytophthora'' (from Greek (''phytón''), "plant" and (), "destruction"; "the plant-destroyer") is a genus of plant-damaging oomycetes (water molds), whose member species are capable of causing enormous economic losses on crops worldwide, a ...

'', ''

Pythium ''Pythium'' is a genus of parasitic oomycetes. They were formerly classified as fungi. Most species are plant parasites, but ''Pythium insidiosum'' is an important pathogen of animals, causing pythiosis. The feet of the fungus gnat are frequen ...

'', ''

Rhizoctonia ''Rhizoctonia'' is a genus of fungi in the order Cantharellales. Species form thin, effused, corticioid basidiocarps (fruit bodies), but are most frequently found in their sterile, anamorphic state. ''Rhizoctonia'' species are saprotrophic, bu ...

'' and ''

Sclerotinia ''Sclerotinia'' is a genus of fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are ...

''.

Sources

* Atkinson, T. G., et al. 1974. Root rot reaction in wheat resistance not mediated by rhizosphere or laimosphere antagonists. ''Phytopathology'' 64:97-101. * Baker, K.F. 1957. The U.C. system for producing healthy container-grown plants. Univ.Calif. Agr. Exp. Sta. Service Manual 23. * Hancock, J. G. 1977. Soluble metabolites in intercellular regions of squash hypocotyl tissues: implications for exudation. ''Plant and Soil'' 47:103-112. * Johnson, L. F., and N. G. Bartley. 1981. Cotton laimosphere populations of microorganisms and their antibiotic effect on Pythium ultimum. ''Phytopathology'' 71:884-981. * Kasuya, M., et al. 2006. Induction of soil suppressiveness against Rhizoctonia solani by incorporation of dried plant residues into soil. ''Phytopathology'' 96: 1372-1379. * Magyarosy, A. C. 1973. Effect of squash mosaic virus infection on microbial populations around the hypocotyl and chloroplast structure and function. Ph.D. Dissertation, Univ. Calif., Berkeley. * Magyarosy, A., and J. G. Hancock. 1972. Microbial population of the laimosphere of squash (Cucurbita maxima) ''Plant and Soil'' 37:187-190. * Magyarosy, A. C., and J. G. Hancock. 1974. Association of virus-induced changes in laimosphere microflora and hypocotyl exudation with protection to Fusarium stem rot. ''Phytopathology'' 64:994-1000. Soil {{ecology-stub