Proteomic Analysis Reveals the Positive Roles of the Plant-Growth-Promoting Rhizobacterium NSY50 in the Response of Cucumber Roots to Fusarium oxysporum f. sp. cucumerinum Inoculation

Abstract

Plant-growth-promoting rhizobacteria (PGPR) can both improve plant growth and enhance plant resistance against a variety of environmental stresses. To investigate the mechanisms that PGPR use to protect plants under pathogenic attack, transmission electron microscopy analysis and a proteomic approach were designed to test the effects of the new potential PGPR strain Paenibacillus polymyxa NSY50 on cucumber seedling roots after they were inoculated with the destructive phytopathogen Fusarium oxysporum f. sp. cucumerinum (FOC). NSY50 could apparently mitigate the injury caused by the FOC infection and maintain the stability of cell structures. The two-dimensional electrophoresis (2-DE) approach in conjunction with MALDI-TOF/TOF analysis revealed a total of 56 proteins that were differentially expressed in response to NSY50 and/or FOC. The application of NSY50 up-regulated most of the identified proteins that were involved in carbohydrate metabolism and amino acid metabolism under normal conditions, which implied that both energy generation and the production of amino acids were enhanced, thereby ensuring an adequate supply of amino acids for the synthesis of new proteins in cucumber seedlings to promote plant growth. Inoculation with FOC inhibited most of the proteins related to carbohydrate and energy metabolism and to protein metabolism. The combined inoculation treatment (NSY50+FOC) accumulated abundant proteins involved in defense mechanisms against oxidation and detoxification as well as carbohydrate metabolism, which might play important roles in preventing pathogens from attacking. Meanwhile, western blotting was used to analyze the accumulation of enolase (ENO) and S-adenosylmethionine synthase (SAMs). NSY50 further increased the expression of ENO and SAMs under FOC stress. In addition, NSY50 adjusted the transcription levels of genes related to those proteins. Taken together, these results suggest that P. polymyxa NSY50 may promote plant growth and alleviate FOC-induced damage by improving the metabolism and activation of defense-related proteins in cucumber roots.

Bacillus velezensis 5113 Induced Metabolic and Molecular Reprogramming during Abiotic Stress Tolerance in Wheat

“…Previous reports have shown that exposing plant to PGPR treatment and abiotic stress factors can result in differential regulation in several genes and proteins which is essential to mount required plant physiological and developmental responses under stress conditions 44–46 . The present study showed that 5113 and stress treatments resulted in both decreased and increased abundance of several proteins connected to several metabolic and stress events and also proteins with unknown function.…”

Proteomic analysis of heat stress resistance of cucumber leaves when grafted onto Momordica rootstock

“…The accumulation level of TK in self-grafted plants increased under heat stress compared to control, whereas it was down-regulated in plants grafted onto Momordica rootstock under heat stress, and indicated a relatively stable pentose phosphate pathway in Momordica-grafted plants. Enolase (ENO) (spot 73) is one of the most important enzymes related to glycolysis and it catalyzes the dehydration of 2-phosphoglycerate into phosphoenolpyruvate 38 . The expression of ENO was similar to TK.…”

Amelioration of drought effects in wheat and cucumber by the combined application of super absorbent polymer and potential biofertilizer

“…NSY50, Bacillus, and Pseudomonas sp. MS16 enhanced the growth of peanut, cucumber, rice, wheat and respectively (Sharma, Kulkarni & Jha, 2016; Du et al, 2016; Feng et al, 2017; Muhammad et al, 2018). However, with the combination use of SAP (BJ-18 + SAP group and L-56 + SAP group), the above parameters (length, FW, DW) were significantly elevated in both wheat and cucumber seedlings as compared to the corresponding control.…”