Endophytic bacterial communities in tomato plants with differential resistance to Ralstonia solanacearum

Abstract

The endophytic bacterial communities in tomato varieties having differing resistance (or susceptibility) to Ralstonia solanacearum were investigated using both cultivation dependent and independent approaches. Both approaches revealed the differences between resistant (Xiahong-1) and susceptible (Baoshi-5) cultivars in terms of diversity and abundance of endophytic bacteria. The amount of the endogenous bacteria in Xiahong-1 at different growth stages was significantly higher than that in Baoshi-5. Furthermore, there were more culturable and antagonistic endophytic bacteria in Xiahong-1 than that in Baoshi-5. Seven endophytic bacterial genetic groups were identified in Xiahong-1 by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and 16S rDNA sequence, and they were highly similar to Sphingomonas yanoikuya, Pseudomonas pseudoalcaligenes, Serratia marcescens, Bacillus megaterium, Paenibacillus polymyxa, B. pumilus and B. cereus. Four groups were identified in Baoshi-1 which were highly similar to S. yanoikuyae, Pseudomonas fluorescens, Arthrobacter globiformis and Paenibacillus polymyxa. In addition, antagonistic endophytes were identified by 16S rRNA gene analysis, and tested for their abilities to protect tomato plants from infection with R. solanacearum. The relationships between plant resistance and endophytic bacteria diversity are discussed.

Potential of Bacterial Endophytes as Plant Growth Promoting Factors

“…Four groups were identified in were highly similar to S. yanoikuyae, Pseudomonas fluorescens, Arthrobacter globiformis and Paenibacillus polymyxa [16]. Hopefully, this information will facilitate a more advanced understanding of how endophytes can be used in the field to improve crop production.…”

“…S. yanoikuyae, Pseudomonas fluorescens, Arthrobacter globiformis and Paenibacillus polymyxa. In addition, antagonistic endophytes were identified by 16S rRNA gene analysis, and tested for their abilities to protect tomato plants from infection with R. solanacearum [16].…”

In-planta Resistance to Panama Wilt of Banana is Modulated by Endophytic Bacteria: A Preliminary Study Supporting the Hypothesis

“…This indicates the probable endophytic modulation of the inplanta resistance in banana against the fusarium wilt disease. Earlier reports have shown that, the population of antagonistic endophytic bacteria against various diseases were found to be higher in resistant genotypes as compared to be the susceptible ones in potato (Sturz and Matheson, 1996), tomato (Feng et al, 2013), tobacco (Ma et al, 2004 and Citrus (Lacava et al, 2004). The formation of inhibition zone as well as the inhibition of the mycelial growth in dual plate screening might be ascribed to the interaction of mycotoxins produced by the fungus and the antifungal metabolites produced by the bacteria (Muller et al, 2014).…”