1997 ). Certain endophytes produce antimicrobial VOC which may directly con-
tribute to defense against pathogens.Muscodor albus, a fungal endophyte originally
isolated from cinnamon tree, emits a blend of VOC that inhibits or kills a broad
range of bacteria, fungi, and oomycetes (Strobel et al. 2001 ). The GC-MS analysis
of its VOC revealed that many of the identified compounds such as 1-butanol and
3-methyl-acetate have antimicrobial activity (Strobel 2006 ; Porras-Alfaro et al.
2011 ).
Some biocontrol fungi appear to employ VOC to control pathogenic fungi
(Hynes et al. 2007 ). For instance, many strains ofTrichodermahave been proven to
effectively prioritize a wide range of soilborne fungal pathogens by employing
mechanisms such as mycoparasitism, nutrient competition, and secretion of inhi-
bitory compounds and hydrolytic enzymes (Lorito et al. 2010 ; Harman 2011 ).
Trichoderma virideandT. aureovirideemitted VOC that inhibit the growth and
protein production ofSerpula lacrymans, a wood-rotting basidiomycete. However,
T. pseudokoningiihad no effect on any of theSerpulaisolates tested, suggesting the
species-specific nature of antifungal VOC production (Humphris et al. 2002 ). Also,
VOC produced byTrichodermaspp. are useful in growth inhibition ofF. oxys-
porumf. sp.ciceris, a soilborne fungal pathogen that causes chickpea wilt (Dubey
et al. 2007 ).F. oxysporumstrain MSA35, which enhanced lettuce growth via VOC
also inhibits the growth of pathogenic strains ofF. oxysporum(Minerdi et al. 2011 ).
11.8 Conclusion
Volatiles are only a minor proportion of the entire number of metabolites produced
by existing organisms. Nevertheless, because of their unique attributes they are
predestined to act as infochemicals in intra- and interspecies communications in the
atmosphere as well as in soil. Among microbes, endophyticfilamentous fungi are
an excellent platform for exploiting biosynthetic routes to hydrocarbon biofuels or
biofuel precursors. In recent years, bacterial and fungal production of volatiles has
emerged as a novel process by which these endophytes modulate plant growth and
induce resistance against abiotic and biotic stresses. Exposure to the volatiles
produced by microbes has been shown to lead to up tofivefold increased plant
biomass or to plant death.
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