Agriculture Reference
In-Depth Information
Chapter 6
Role of Phosphate-Solubilizing
Actinomycetes in Plant Growth Promotion:
Current Perspective
Saima Saif, Mohammad Saghir Khan, Almas Zaidi, and Ees Ahmad
Abstract
Phosphorus (P), an essential plant nutrient, is a nonrenewable resource
whose availability depends exclusively on mined rock phosphates. Deficiency of P
in soil results in reduction in food production since all plants require an adequate
supply of P for its growth and development. Even though synthetic phosphatic
fertilizer has played some major roles in enhancing crop production, its excessive
use has also dark sides to it where it has been found to damage the environment,
destruct soil fertility, and, via food chain, seriously affect the human health.
Considering the nuisance of overuse of P, there is an urgent demand by the
agriculture practitioners to find nonhazardous strategy that can overcome/reduce
the use of agrochemicals in agricultural practices and, hence, may preserve the very
integrity of soil ecosystems. In this context, actinobacteria, a group of Gram-
positive bacteria, ubiquitous in soils, are likely to play some important roles in
supplying soluble P to plants by solubilizing/mineralizing complex P resources of
soils. Additionally, the extracellular metabolites produced by actinomycetes may
inhibit phytopathogens and, sometimes such metabolic compounds may also act as
plant growth regulators. These qualities, among others, make actinobacteria an
ideal candidate for developing as microbial inoculants for ultimate use in agricul-
ture production system. The potential roles of actinomycetes as phosphate
solubilizers in enhancing crop production are discussed.
Keywords
Actinomycetes • P solubilizers • Plant growth • Biocontrol
