Biocontrol of verticillium wilt and colonization of cotton plants by an endophytic bacterial isolate

Abstract

Aims To explore biocontrol potential of 39 DAEB isolates (doubly antagonistic towards both Verticillium dahliae Kleb and Fusarium oxysporum) against verticillium wilt of cotton and to elucidate colonization and category characteristics of an endophytic bacterium with significant biocontrol activity. Methods and Results Thirty‐nine antagonistic endophytic bacteria strains were tested for their ability to control verticillium wilt in cotton plants caused by a defoliating pathotype of V. dahliae 107 in cotton under controlled conditions. The biocontrol trial revealed that an endophytic bacterium, designated HA02, showed a significant biocontrol activity to V. dahliae 107. After cotton seedlings were inoculated with a gfp gene‐tagged HA02 (HA02‐gfp), HA02‐gfp populations were higher in the root than in the stem; in addition, the HA02‐gfp was distributed in the maturation zone of cotton root. Furthermore, HA02‐gfp also colonized seedlings of maize, rape and soybean after the bacteria inoculation. Phylogenetic trees based on 16S rDNA sequences combined with morphological, physiological and identification showed that the bacterium belongs to the Enterobacter genus. Conclusions Our results showed that only 1 of 39 DAEB isolates demonstrated more efficient biocontrol potential towards V. dahliae 107 in greenhouse and field trials. HA02‐gfp mainly colonized cotton in roots. In addition, we quantitatively observed HA02 colonization in other hosts. HA02 belongs to the Enterobacter genus. Significance and Impact of the Study This is the first study on biocontrol to defoliating pathotype of V. dahliae Kleb by endophytic bacteria. The HA02 showed effective biocontrol to V. dahliae 107 in greenhouse and field trials. Furthermore, we assessed the quantitative and qualitative colonization of HA02 in cotton seedlings. Our study provides basic information to further explore managing strategies to control this critical disease.

Scoping the potential uses of beneficial microorganisms for increasing productivity in cotton cropping systems

“…Further, treatment with Pseudomonas spp., T. virens or Enterobacter sp. HA02 decrease wilt incidence and improve cotton growth parameters (Hanson, 2000;Erdogan and Benlioglu, 2010;Li et al, 2012). Similarly, mycorrhizal fungi of Glomus spp.…”

Potential of Endophytic Fungi Isolated from Cotton Roots for Biological Control against Verticillium Wilt Disease

“…and Serratia plymutica , have been shown to be effective antagonists of Verticillium wilt [7–8]. Recent studies have indicated that endophytes colonize the internal tissues of plants and can improve plant growth and plant health [9–11]. …”

Purification and antibiofilm activity of AHL-lactonase from endophytic Enterobacter aerogenes VT66

“…Page 7 of 28 A c c e p t e d M a n u s c r i p t 7 The inhibition of biofilm formed by P. aeruginosa PAO1was tested using microtiter plate assay [19] with some modifications. Briefly, P. aeruginosa PAO1 was grown at 37 ºC for 18 h in tryptic soy broth (TSB, Himedia, India).…”

“…Endophytes are known to colonize internal tissues of the plants without causing disease and said to be endosymbionts [7]. The endophytic bacterial population within plant reflects the great genetic and metabolic diversity.…”