(ISR). Myriad of bacteria has been documented for beneficial effects, alleviation of
several abiotic and biotic stresses.PseudomonasandBacillussp., have been studied
as potential candidate to provide ISR to plants (Chakraborty et al. 2006 )
In earlier days, autofluorescent protein marker (AFP) were studied using stan-
dard microbiological enumeration associated with plant surfaces and in planta
protein (AFP) (Tombolini et al. 1997 ; Tombolini and Jansson 1998 ). The colo-
nization mechanisms of endophyte colonization have also been investigated to be
utilized asb-glucuronidase (GUS) reporter system. James et al. ( 2002 ) used this
technique in whichHerbaspirillum seropedicaeZ67 was inoculated on to rice
seedlings via GUS stain where it acted as most severe oncoleoptiles. It was
incultated that the endophytes have entered in the roots via small lesions or cracks
in the root tissues at the point from where the lateral root emerged and subsequent
to this become colonized in the intercellular spaces of root tissues, paerenchyma
and cortical cells, and further disaminated towards xylem vessels of stems and
leaves. In the exampled study, it was concluded that a compatible host plant is
necessarily needed for successful colonization. An endophyteAzoarcussp. strain
BH72 expressedNifgenes in rice roots evaluated using proteomic approaches and
jasmonic acid treatment to dissect rice roots responsed for colonization (which
induces plant defence proteins). The strategies of adaption have been used to
decipher the expression vivo expression technology (IVET) and recombination
in vivo expression of bacterial gene in the rhizosphere and phyllosphere (Leveau
and Lindow 2001 ; Preston et al. 2001 ; Zhang et al. 2006 ) The insights of these
studies may provide importance of genes required by bacteria to enter, compete and
be colonized in the plant and suppress phytopathogens (Table7.1).
Table 7.1 List of endophytic bacteria isolated from major agricultural crops
Plant origin Phylum Endophytic bacteria References
Black
pepperFirmicutes Bacillussp. Aravind et al.
Gamma proteo (^2009 )
bacteriaPseudomonassp.Citrus Firmicutes Bacillus cereus,B. lentus, B.
Pumilis, B. subtilis, B. megateriumAraujo et al.
( 2001 )
Cotton Gamma proteo
bacteriaEnterobactersp. Musson et al.
( 1995 )
Canola Firmicutes Bacillussp. Germida et al.
Actinobacteria Micrococcussp. (^1998 )
Grapes b-protobacteria Comamonassp. Bell et al. ( 1995 )
Gamma proteo
bacteriaPseudomonas cichori,
Xanthomonassp.Moraxella bovis,
Enterobactersp.West et al. ( 2010 )Kallar grass b-protobacteria Azoarcussp. Krause et al.
( 2006 )
Maize Gamma proteo
bacteriaKilebsiella pneumoniae Fouts et al.
( 2008 )
(continued)138 A. Muthukumar et al.