2,4-diacetylphloroglucinol: A novel biotech bioactive compound for agriculture

Abstract

Soil-borne phytopathogens are responsible for 30% loss of crop productivity and difficult to control. Strategies including crop rotation, use of chemical pesticides and even breeding and genetic engineering efforts for resistant plant varieties demonstrate limited potency to control root diseases of the agricultural plants. Applications of chemical fungicides to crop plant arrest fungal pathogen to some extent but impart acute and chronic toxicity to plants and interrupt biogeochemical cycles. The synthetic chemical fertilizers and pesticides are widely used in the last two to three decades, and the biological control relied on use of rhizobacteria or their bioactive metabolites to suppress the pathogen or pest load. Now, biological control proved beneficial to improve food security and livelihood, reduce contamination of soil and crops from pesticides and eventually increase biodiversity. The rhizobacteria are eco-friendly, stimulate the plant growth factors, provide nutrition for healthy growth of plant and reduce the incidence of crop diseases. The effective colonization of the rhizosphere and secretion of antibiotics by rhizobacteria determine biocontrol activity. Plant-growth-promoting rhizobacteria (PGPR) produce secondary metabolites such as pyoluteorin, pyrrolnitrin, phenazine, 2,4-diacetyl phloroglucinol (DAPG), etc. Of these, DAPG, a novel bioactive metabolite of the polyketide pathway, is of particular significance, because of (i) broad-spectrum effect against plant viruses, phytopathogenic bacteria and fungi for root diseases of dicots as well as monocots such as cucumber, maize, pea, tobacco, tomato, wheat, oat, banana, cotton, sugar beet, rice, etc. and (ii) its production by the native rhizospheric PGP fluorescent Pseudomonas spp. In addition, DAPG has also shown anti-helminthic, antiviral, and anti-protozoal properties as well as anticancer activity with pharmaceutical applications. This article mainly focuses on the laboratory to industry route for DAPG production with the aim to understand microbial DAPG biosynthesis and production for sustainable agriculture purpose.