Biocontrol Efficacy of Endophyte Pseudomonas poae to Alleviate Fusarium Seedling Blight by Refining the Morpho-Physiological Attributes of Wheat

Abstract

Some endophyte bacteria can improve plant growth and suppress plant diseases. However, little is known about the potential of endophytes bacteria to promote wheat growth and suppress the Fusarium seedling blight pathogen Fusarium graminearum. This study was conducted to isolate and identify endophytic bacteria and evaluate their efficacy for the plant growth promotion and disease suppression of Fusarium seedling blight (FSB) in wheat. The Pseudomonas poae strain CO showed strong antifungal activity in vitro and under greenhouse conditions against F. graminearum strain PH-1. The cell-free supernatants (CFSs) of P. poae strain CO were able to inhibit the mycelium growth, the number of colonies forming, spore germination, germ tube length, and the mycotoxin production of FSB with an inhibition rate of 87.00, 62.25, 51.33, 69.29, and 71.08%, respectively, with the highest concentration of CFSs. The results indicated that P. poae exhibited multifarious antifungal properties, such as the production of hydrolytic enzymes, siderophores, and lipopeptides. In addition, compared to untreated seeds, wheat plants treated with the strain showed significant growth rates, where root and shoot length increased by about 33% and the weight of fresh roots, fresh shoots, dry roots, and dry shoots by 50%. In addition, the strain produced high levels of indole-3-acetic acid, phosphate solubilization, and nitrogen fixation. Finally, the strain demonstrated strong antagonistic properties as well as a variety of plant growth-promoting properties. Thus, this result suggest that this strain could be used as an alternate to synthetic chemicals, which can serve as an effective method of protecting wheat from fungal infection.

Novel Endophytic Pseudescherichia sp. GSE25 Strain Significantly Controls Fusarium graminearum and Reduces Deoxynivalenol in Wheat

“…Colony growth of PH-1 was inhibited at a range between 15% and 25%. In agreement with the obtained results from the current study, previous studies have indicated that the endophytic B. vallismortis ZZ185 and P. poae strain CO can be used as antifungal agents to suppress F. graminearum [ 11 , 38 ]. The fungal cell wall is crucial in determining cell shape and protecting fungal cells from external stress [ 39 ].…”

“…Currently, fungicides are mainly used to prevent and control FHB in the wheat flowering period. However, the resistance of F. graminearum to chemical pesticides increases with excessive use and even results in ineffective fungicides [ 11 ]. Hence, there is an urgent need to isolate and identify effective endophytic microbes from wheat fields to be used as an alternative to synthetic chemicals.…”

“…Due to the scarcity of resistant varieties, the use of fungicides has become the prevalent approach to control the FHB in farmland. Furthermore, excessive or long-term use of chemical fungicides increases the resistance of F. graminearum [ 11 ]. For these reasons, the use of endophytic bacteria as a biocontrol agent is a new strategy that has a great potential to control phytopathogens.…”

“…Similarly, B. velezensis SDTB038 is a highly efficient endophytic bacterium that could colonize the tomato plant and produce indoleacetic acid to promote tomato plant growth, which has a better biocontrol effect on Fusarium crown and root rot of tomato [ 10 ]. Ibrahim et al documented that the endophytic bacterium Pseudomonas poae strain exhibited multifarious antifungal properties through the production of hydrolytic enzymes, siderophores, and lipopeptides, showing potent antifungal activity against F. graminearum PH-1 when tested under in vitro and greenhouse conditions [ 11 ].…”

Antifungal Activity of Phyllospheric Bacteria Isolated from Coffea arabica against Hemileia vastatrix

“…One mechanism that is widely reported is the ability of Pseudomonas spp. to produce siderophores to obtain Fe +3 from the rhizosphere, preventing phytopathogens from accessing this nutrient [ 37 ]. Moreover, it has been reported that bacterial siderophores affected spore germination and mycelial growth in some phytopathogenic fungi [ 38 ].…”