In wild tobacco,<i>Nicotiana attenuata</i>, variation among bacterial communities of isogenic plants is mainly shaped by the local soil microbiota independently of the plants' capacity to produce jasmonic acid

Santhanam, Rakesh; Baldwin, Ian Thomas; Groten, Karin

doi:10.1080/19420889.2015.1017160

Cited by 9 publications

(17 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present study, in an in vitro assay, the mortality rate did not differ among WT and seedlings impaired in JA biosynthesis (Supporting Information Figure c), although it has to be stressed that in this assay the biocontrol agent and the phytopathogens were not spatially separated, which is the case for ISR. These results are consistent with a field study with empty vector (EV) control plants and the same JA‐deficient lines, which did not differ in their resistance to the fungal disease (Santhanam, Baldwin et al, ). Furthermore, here we show that JA levels were only increased after pathogen treatment (F), but not after treatment with the consortium + pathogen (BF) or the consortium only (Supporting Information Table ).…”

Section: Discussionsupporting

confidence: 89%

“…Typical symptoms of the disease are the sudden collapse of the vascular system and the roots turning black (Santhanam, Luu et al, ; Schuck et al, ). The beneficial consortium that protected plants from the sudden wilt disease consisted of five bacteria isolated from soils in the plant's native habitat (Santhanam, Baldwin, & Groten, ). The strains were isolated from different field‐grown plants: Bacillus megaterium B55 was shown to rescue the growth of an ethylene‐insensitive line in the field (Long, Sonntag, Schmidt, & Baldwin, ; Meldau, Long, & Baldwin, ) by enhancing sulphur nutrition of N. attenuata (Meldau et al, ), and the remaining four species, Bacillus mojavensis K1 , Pseudomonas frederiksbergensis A176 , P. azotoformans A70 and Arthrobacter nitroguajacolicus E46, promoted the growth of control plants and of plants impaired in the production of the phytohormomone jasmonic acid (JA) (Santhanam, Baldwin et al, ; Santhanam, Groten, Meldau, & Baldwin, ).…”

Section: Introductionmentioning

confidence: 99%

“…The beneficial consortium that protected plants from the sudden wilt disease consisted of five bacteria isolated from soils in the plant's native habitat (Santhanam, Baldwin, & Groten, ). The strains were isolated from different field‐grown plants: Bacillus megaterium B55 was shown to rescue the growth of an ethylene‐insensitive line in the field (Long, Sonntag, Schmidt, & Baldwin, ; Meldau, Long, & Baldwin, ) by enhancing sulphur nutrition of N. attenuata (Meldau et al, ), and the remaining four species, Bacillus mojavensis K1 , Pseudomonas frederiksbergensis A176 , P. azotoformans A70 and Arthrobacter nitroguajacolicus E46, promoted the growth of control plants and of plants impaired in the production of the phytohormomone jasmonic acid (JA) (Santhanam, Baldwin et al, ; Santhanam, Groten, Meldau, & Baldwin, ). We selected strains of the genera Bacillus and Pseudomonas because the bioprotective traits of several strains of these genera are known (Caulier et al, ; Jangir, Pathak, Sharma, & Sharma, ; Pandin, Coq, Canette, Aymerich, & Briandet, ), but few studies have examined different bioprotective strains functioning together in protective consortia.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A suite of complementary biocontrol traits allows a native consortium of root‐associated bacteria to protect their host plant from a fungal sudden‐wilt disease

et al. 2019

Self Cite

View full text Add to dashboard Cite

The beneficial effects of plant‐–bacterial interactions in controlling plant pests have been extensively studied with single bacterial isolates. However, in nature, bacteria interact with plants in multitaxa consortia, systems which remain poorly understood. Previously, we demonstrated that a consortium of five native bacterial isolates protected their host plant Nicotiana attenuata from a sudden wilt disease. Here we explore the mechanisms behind the protection effect against the native pathosystem. Three members of the consortium, Pseudomonas azotoformans A70, P. frederiksbergensis A176 and Arthrobacter nitroguajacolicus E46, form biofilms when grown individually in vitro, and the amount of biofilm increased synergistically in the five‐membered consortium, including two Bacillus species, B. megaterium and B. mojavensis. Fluorescence in situ hybridization and scanning electron microscopy in planta imaging techniques confirmed biofilm formation and revealed locally distinct distributions of the five bacterial strains colonizing different areas on the plant‐root surface. One of the five isolates, K1 B. mojavensis produces the antifungal compound surfactin, under in vitro and in vivo conditions, clearly inhibiting fungal growth. Furthermore, isolates A70 and A176 produce siderophores under in vitro conditions. Based on these results we infer that the consortium of five bacterial isolates protects its host against fungal phytopathogens via complementary traits. The study should encourage researchers to create synthetic communities from native strains of different genera to improve bioprotection against wilting diseases.

show abstract

Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A suite of complementary biocontrol traits allows a native consortium of root‐associated bacteria to protect their host plant from a fungal sudden‐wilt disease

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Oi3, which were isolated from diseased plants but were reported to be potential biocontrol agents (28,29), and six native bacterial isolates (Arthrobacter nitroguajacolicus E46, Bacillus cereus CN2, Bacillus megaterium B55, Bacillus mojavensis K1, Pseudomonas azotoformans A70, and Pseudomonas frederiksbergensis A176), which had been isolated from the roots of healthy N. attenuata plants from the same field location (12,14). The selection of these bacterial isolates was based on in vitro plant growth-promoting effects on N. attenuata (15,30); the isolates had been reported as biocontrol agents in the literature (28,29,31).…”

Section: Resultsmentioning

confidence: 99%

Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping

Santhanam

Luu

Weinhold

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

363

229

View full text Add to dashboard Cite

Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant’s native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to a Fusarium–Alternaria disease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem for N. attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems.

show abstract

“…In contrast, strong differences were observed between the microbiomes of roots and shoots (Santhanam et al . , ).…”

Section: Introductionmentioning

confidence: 99%

Specificity of root microbiomes in native‐grown Nicotiana attenuata and plant responses to UVB increase Deinococcus colonization

Santhanam

Kumar

et al. 2017

Molecular Ecology

Self Cite

View full text Add to dashboard Cite

Plants recruit microbial communities from the soil in which they germinate. Our understanding of the recruitment process and the factors affecting it is still limited for most microbial taxa. We analysed several factors potentially affecting root microbiome structure - the importance of geographic location of natural populations, the microbiome of native seeds as putative source of colonization and the effect of a plant's response to UVB exposure on root colonization of highly abundant species. The microbiome of Nicotiana attenuata seeds was determined by a culture-dependent and culture-independent approach, and the root microbiome of natural N. attenuata populations from five different locations was analysed using 454-pyrosequencing. To specifically address the influence of UVB light on root colonization by Deinococcus, a genus abundant and consistently present in N. attenuata roots, transgenic lines impaired in UVB perception (irUVR8) and response (irCHAL) were investigated in a microcosm experiment with/without UVB supplementation using a synthetic bacterial community. The seed microbiome analysis indicated that N. attenuata seeds are sterile. Alpha and beta diversities of native root bacterial communities differed significantly between soil and root, while location had only a significant effect on the fungal but not the bacterial root communities. With UVB supplementation, root colonization of Deinococcus increased in wild type, but decreased in irUVR8 and irCHAL plants compared to nontreated plants. Our results suggest that N. attenuata recruits a core root microbiome exclusively from soil, with fungal root colonization being less selective than bacterial colonization. Root colonization by Deinococcus depends on the plant's response to UVB.

show abstract

In wild tobacco,Nicotiana attenuata, variation among bacterial communities of isogenic plants is mainly shaped by the local soil microbiota independently of the plants' capacity to produce jasmonic acid

Cited by 9 publications

References 28 publications

A suite of complementary biocontrol traits allows a native consortium of root‐associated bacteria to protect their host plant from a fungal sudden‐wilt disease

A suite of complementary biocontrol traits allows a native consortium of root‐associated bacteria to protect their host plant from a fungal sudden‐wilt disease

Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping

Specificity of root microbiomes in native‐grown Nicotiana attenuata and plant responses to UVB increase Deinococcus colonization

Contact Info

Product

Resources

About