Growth Promotion of Pepper Plants by Pantoea ananatis B1-9 and its Efficient Endophytic Colonization Capacity in Plant Tissues

Abstract

The bacteria B1-9 that was isolated from the rhizosphere of the green onion could promote growth of pepper, cucumber, tomato, and melon plants. In particular, pepper yield after B1-9 treatment on the seedling was increased about 3 times higher than that of control plants in a field experiment. Partial 16S rDNA sequences revealed that B1-9 belongs to the genus Pantoea ananatis. Pathogenecity tests showed non-pathogenic on kimchi cabbage, carrot, and onion. The functional characterization study demonstrated B1-9's ability to function in phosphate solubilization, sulfur oxidation, nitrogen fixation, and indole-3-acetic acid production. To trace colonization patterns of B1-9 in pepper plant tissues, we used DRAQ5™ fluorescent dye, which stains the DNAs of bacteria and plant cells. A large number of B1-9 cells were found on the surfaces of roots and stems as well as in guard cells. Furthermore, several colonized B1-9 cells resided in inner cortical plant cells. Treatment of rhizosphere regions with strain B1-9 can result in efficient colonization of plants and promote plant growth from the seedling to mature plant stage. In summary, strain B1-9 can be successfully applied in the pepper plantation because of its high colonization capacity in plant tissues, as well as properties that promote efficient plant growth.

Isolation of Pantoea ananatis from sugarcane and characterization of its potential for plant growth promotion

“…In fact, only one other study on P. ananatis B1-9 strain isolated from the rhizosphere of onions showed potential for promoting plant growth in peppers, cucumbers, and melons (Kim et al, 2012).…”

“…Auxins are typically used in agriculture to stimulate plant growth through root development (Benjamins and Scheres, 2008). According to Kim et al (2012), the production of IAA by P. ananatis B1-9 is the most important factor for growth and fruit production in pepper plants. Another study has shown that P. ananatis 125NP12 isolated from tomato plants is capable of producing IAA.…”

Promising bacterial genera for agricultural practices: An insight on plant growth-promoting properties and microbial safety aspects

“…Siderophore production. The production of siderophores was described for several Pantoea species, such as Pantoea agglomerans, Pantoea eucalyptii (Viruel et al, 2011), Pantoea allii (Pereira and Castro, 2014), Pantoea ananatis (Kim et al, 2012;Loaces et al, 2011), as well as for other Pantoea species (Loaces et al, 2011). However, little is known about these siderophores.…”

“…strains (Trifi et al, 2017). In addition, nutrient based promoting traits, such as phosphate solubilization or nitrogen fixation (Kim et al, 2012) were described. The biocontrol potential of Pantoea spp.…”

“…isolates for agronomic practices was tested in pot or field studies. Thus, the increased mass in plant bean (Gopalakrishnan et al, 2017), and in canola (Trifi et al, 2017), biocontrol action in mulberry seedlings (Xie et al, 2017), Fe intake in Lotus japonicus (Campestre et al, 2016), root development in olive trees (Montero-Calasanz et al, 2013), and increased crop yield and biomass in tomato, cucumber or pepper (Kim et al, 2012) was described.…”