Beneficial Effect and Potential Risk of Pantoea on Rice Production

Abstract

Bacteria from the genus Pantoea have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected rice from pathogen infection or abiotic stress, but other strain exhibited virulence to rice, even causing severe rice disease. In order to effectively utilize Pantoea in rice production, this paper analyzed the mechanisms underlying beneficial and harmful effects of Pantoea on rice growth. The beneficial effect of Pantoea on rice plants includes growth promotion, abiotic alleviation and disease inhibition. The growth promotion may be mainly attributed to nitrogen-fixation, phosphate solubilization, plant physiological change, the biosynthesis of siderophores, exopolysaccharides, 1-aminocyclopropane-1-carboxylic acid deaminase and phytohormones, including cytokinin, indole-3-acetic acid (IAA), auxins, abscisic acid and gibberellic acid, while the disease inhibition may be mainly due to the induced resistance, nutrient and spatial competition, as well as the production of a variety of antibiotics. The pathogenic mechanism of Pantoea can be mainly attributed to bacterial motility, production of phytohormones such as IAA, quorum sensing-related signal molecules and a series of cell wall-degrading enzymes, while the pathogenicity-related genes of Pantoea include genes encoding plasmids, such as the pPATH plasmid, the hypersensitive response and pathogenicity system, as well as various types of secretion systems, such as T3SS and T6SS. In addition, the existing scientific problems in this field were discussed and future research prospects were proposed.

Pantoea vagans causing soft rot disease in Agave angustifolia, in Mexico

“…Although the genus Pantoea is known as a phytopathogen, studies are reported in which they have a beneficial effect on plants, especially in promoting growth and controlling phytopathogens (Lorenzi et al., 2022; Lv et al., 2022; Pusey, 2002).…”

Seeds of Stevia rebaudiana Bertoni as a Source of Plant Growth-Promoting Endophytic Bacteria with the Potential to Synthesize Rebaudioside A

“…Anjum and Chandra [34] have already reported isolation from stevia plants of the bacteria belonging to the genus Pantoea, although species identification was not performed in that work. Originally, Pantoea was known as a plant pathogen; however, today, it is generally known that these bacteria have a beneficial effect on plants, especially in growth promotion and phytopathogen control [53][54][55][56]. P. vagans is very often isolated together with P. agglomerans since both species occupy the same ecological niches, and even some isolated P. vagans strains were previously identified as P. agglomerans [57].…”

Studying Plant–Insect Interactions through the Analyses of the Diversity, Composition, and Functional Inference of Their Bacteriomes

“…The nitrogen fixation by bacterial species such as Azotobacter , Clostridium , or Rhizobium has been reported to be of vital importance in plant growth [ 118 ]. Some of the genera found exclusively in the plant tissues like Pseudomonas [ 119 ], Pantoea [ 120 ], and Siccibacter [ 121 ] have been associated with nitrogen fixation and auxin biosynthesis [ 122 ]. It should be noted that rhizobacteria such as Bacillus amyloliquefaciens and Pseudomonas putida can promote the activation of the jasmonic acid and salicylate acid pathway, which increases the resistance levels to insects such as caterpillars [ 123 ].…”