Saran's Learn Microbiology

PLANT GROWTH PROMOTING RHIZOBACTERIA (PGPR) The group of bacteria that colonize roots or rhizosphere soil and beneficial to crops are referred to as Plant Growth Promoting Rhizobacteria (PGPR). Rhizosphere consists of bacteria named rhizobacteria which either directly or indirectly exert positive effects on plants. These soil bacteria colonize plant root and benefit the plants by stimulating its growth and are therefore called plant growth promoting rhizobacteria (PGPR). PGPR can also be referred to as Plant Health Promoting Rhizobacteria (PHPR) The concept of Rhizosphere was first given by Hiltner in 1904. The term PGPR was first coined by Joseph W. Kloepper and Schroth in the late 1970s. Bacteria belonging to the genera Azospirillum sp., Azotobacter sp. , Azoarcus sp., Arthrobacter sp., Klebsiella sp., Burkholderia sp., Citrobacter sp., Pseudomonas sp., Bacillus sp., Paenibacillus sp., Herbaspiril

PLANT - MICROBE INTERACTION The interactions of plants with microbes both in the soil and above ground shoot are of great importance for the growth and productivity of plants in agricultural and natural ecosystems. Many microbe-plant interactions do no harm to the plant, whereas the microbe gains some advantage. Such relationships, in which one partner benefits but the other is neither hurt nor helped, is called Commensalism. Many other important interactions are beneficial to both the microorganism and the plant (i.e., are mutualistic). Microbe-plant interactions can be broadly divided into two classes: a)      Epiphytes - Microbes that live on the surface of plants are called Epiphytes. b)      Endophytes - Microbes that colonize internal plant tissues are called Endophytes.   PHYLLOSPHERE MICROORGANISMS The Phyllosphere is a term used in microbiology to refer to the total above-ground portions of plants as h