A genetic tool for production of GFP-expressing Rhodopseudomonas palustris for visualization of bacterial colonization

Abstract

Development of a genetic tool for visualization of photosynthetic bacteria (PSB) is essential for understanding microbial function during their interaction with plant and microflora. In this study, Rhodopseudomonas palustris GJ-22-gfp harboring the vector pBBR1-pckAPT-gfp was constructed using an electroporation transformation method and was used for dynamic tracing of bacteria in plants. The results showed that strain GJ-22-gfp was stable and did not affect the biocontrol function, and the Confocal Laser Scanning Microscopy (CLSM) results indicated it could successfully colonised on the surface of leaf and root of tobacco and rice. In tobacco leaves, cells formed aggregates on the mesophyll epidermal cells. While in rice, no aggregate was found. Instead, the fluorescent cells colonise the longitudinal intercellular spaces between epidermal cells. In addition, the results of strain GJ-22 on the growth promotion and disease resistance of tobacco and rice indicated that the different colonization patterns might be related to the bacteria could induce systemic resistance in tobacco.

Synthetic Biology Tool Development Advances Predictable Gene Expression in the Metabolically Versatile Soil Bacterium Rhodopseudomonas palustris

“…The background fluorescence produced by photosynthetic microbes like R. palustris can complicate the use of such an important tool. The gene for green fluorescent protein (GFP) has been expressed in R. palustris CGA009 ( Doud et al, 2017 ) as well as another R. palustris strain, GJ-22 ( Zhai et al, 2019 ), but the use of other fluorescent proteins has not been reported. To determine the fluorescent reporter best suited for work in R. palustris , the fluorescence of wild type R. palustris was determined (Materials and Methods) for the excitation and emission wavelengths of GFPuv, enhanced yellow fluorescent protein (eYFP), and monomeric red fluorescent protein (mRFP) ( Figure 2A ).…”

Diversity and functional characterization of endophyticMethylobacteriumisolated from banana cultivars of South India and its impact on early growth of tissue culture banana plantlets

“…Growth curves of gfp-labelled and wildtype M. salsuginis TNMB03 were measured to determine whether the addition of gfp affects growth and metabolism. Wild-type strain M. salsuginis TNMB03 and TNMB03-gfp were cultured in the same conditions and population count was taken at different time intervals (Zhai et al 2019). The observed growth pattern did not show any differences between gfp transformed and wild type M. salsuginis (data not shown).…”

Synthetic Biology Tool Development Advances Predictable Gene Expression in the Metabolically Versatile Soil Bacterium Rhodopseudomonas palustris

“…The background fluorescence produced by photosynthetic microbes like R. palustris can complicate the use of such an important tool. The gene for green fluorescent protein (GFP) has been expressed in R. palustris CGA009 (Doud et al, 2017) as well as another R. palustris strain, GJ-22 (Zhai et al, 2019), but the use of other fluorescent proteins has not been reported. To determine the fluorescent reporter best suited for work in R. palustris, the fluorescence of wild type R. palustris was determined (Materials and Methods) for the excitation and emission wavelengths of GFPuv, enhanced yellow fluorescent protein (eYFP), and monomeric red fluorescent protein (mRFP) (Figure 1c).…”