Variovorax sp. Has an Optimum Cell Density to Fully Function as a Plant Growth Promoter

Natsagdorj, Oyungerel; Sakamoto, Hisayo; Santiago, Dennis Marvin; Santiago, Christine D.; Orikasa, Yoshitake; Okazaki, Kazuyuki; Ikeda, Seishi; Ohwada, Takuji

doi:10.3390/microorganisms7030082

“…Variovorax sp. promoted plant growth via producing plant growth substances and enzymes such as siderophores and ACC deaminase [ 84 ]. These results suggest that both antagonistic and PGP microbes might contribute to the improvement of wheat growth and tolerance to AG8.…”

Section: Discussionmentioning

confidence: 99%

Rhizosphere community selection reveals bacteria associated with reduced root disease

Yin

¹

,

Vargas

²

,

Schlatter

³

et al. 2021

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Background Microbes benefit plants by increasing nutrient availability, producing plant growth hormones, and protecting against pathogens. However, it is largely unknown how plants change root microbial communities. Results In this study, we used a multi-cycle selection system and infection by the soilborne fungal pathogen Rhizoctonia solani AG8 (hereafter AG8) to examine how plants impact the rhizosphere bacterial community and recruit beneficial microorganisms to suppress soilborne fungal pathogens and promote plant growth. Successive plantings dramatically enhanced disease suppression on susceptible wheat cultivars to AG8 in the greenhouse. Accordingly, analysis of the rhizosphere soil microbial community using deep sequencing of 16S rRNA genes revealed distinct bacterial community profiles assembled over successive wheat plantings. Moreover, the cluster of bacterial communities formed from the AG8-infected rhizosphere was distinct from those without AG8 infection. Interestingly, the bacterial communities from the rhizosphere with the lowest wheat root disease gradually separated from those with the worst wheat root disease over planting cycles. Successive monocultures and application of AG8 increased the abundance of some bacterial genera which have potential antagonistic activities, such as Chitinophaga, Pseudomonas, Chryseobacterium, and Flavobacterium, and a group of plant growth-promoting (PGP) and nitrogen-fixing microbes, including Pedobacter, Variovorax, and Rhizobium. Furthermore, 47 bacteria isolates belong to 35 species were isolated. Among them, eleven and five exhibited antagonistic activities to AG8 and Rhizoctonia oryzae in vitro, respectively. Notably, Janthinobacterium displayed broad antagonism against the soilborne pathogens Pythium ultimum, AG8, and R. oryzae in vitro, and disease suppressive activity to AG8 in soil. Conclusions Our results demonstrated that successive wheat plantings and pathogen infection can shape the rhizosphere microbial communities and specifically accumulate a group of beneficial microbes. Our findings suggest that soil community selection may offer the potential for addressing agronomic concerns associated with plant diseases and crop productivity.

show abstract

“…Variovorax sp. promoted plant growth via producing plant growth substances and enzymes such as siderophores and ACC deaminase [81]. These results suggest that both antagonistic and PGP microbes might contribute to improve wheat growth and tolerance to AG8.…”

Section: Discussionmentioning

confidence: 80%

Rhizosphere Community Selection Reveals Bacteria Associated With Reduced Root Disease

Paulitz

¹

,

Yin

²

,

Vargas

³

et al. 2020

Preprint

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Background: Microbes benefit plants by increasing nutrient availability, producing plant growth hormones, and protecting against pathogens. However, it is largely unknown how plants change root microbial communities. Results: In this study, we used a multi-cycle selection system and infection by the soilborne fungal pathogen Rhizoctonia solani AG8 (hereafter AG8) to examine how plants impact the rhizosphere bacterial community and recruit beneficial microorganisms to suppress soilborne fungal pathogens and promote plant growth. Successive plantings dramatically enhanced disease suppression on susceptible wheat cultivars to AG8 in the greenhouse. Accordingly, analysis of the rhizosphere soil microbial community using deep sequencing of 16S rRNA genes revealed distinct bacterial community profiles assembled over successive wheat plantings. Moreover, the cluster of bacterial communities formed from the AG8-infected rhizosphere was distinct from those without AG8 infection. Interestingly, the bacterial communities from the rhizosphere with the lowest wheat root disease gradually separated from those with the worst wheat root disease over planting cycles. Successive monocultures and application of AG8 increased the abundance of some bacterial genera which have potential antagonistic activities, such as Chitinophaga, Pseudomonas, Chryseobacterium, and Flavobacterium, and a group of plant growth-promoting (PGP) and nitrogen-fixing microbes, including Pedobacter, Variovorax, and Rhizobium. Furthermore, 47 bacteria isolates belong to 35 species were isolated. Among them, eleven and five exhibited antagonistic activities to AG8 and Rhizoctonia oryzae in vitro, respectively. Notably, Janthinobacterium displayed broad antagonism against the soilborne pathogens Pythium ultimum, AG8, and R. oryzae in vitro, and disease suppressive activity to AG8 in soil. Conclusions: Our results demonstrated that successive wheat plantings and pathogen infection can shape the rhizosphere microbial communities and specifically accumulate a group of beneficial microbes. Our findings suggest that soil community selection may offer the potential for addressing agronomic concerns associated with plant diseases and crop productivity.

show abstract

“…Variovorax sp. promoted plant growth via producing plant growth substances and enzymes such as siderophores and ACC deaminase [86]. These results suggest that both antagonistic and PGP microbes might contribute to improve wheat growth and tolerance to AG8.…”

Section: Discussionmentioning

confidence: 80%

Rhizosphere community selection reveals bacteria associated with reduced root disease 

Paulitz

¹

,

Yin

²

,

Vargas

³

et al. 2020

Preprint

0

View full text Add to dashboard Cite

Background: Microbes benefit plants by increasing nutrient availability, producing plant growth hormones, and protecting against pathogens. However, it is largely unknown how plants change root microbial communities. Results: In this study, we used a multi-cycle selection system and infection by the soilborne fungal pathogen Rhizoctonia solani AG8 (hereafter AG8) to examine how plants impact the rhizosphere bacterial community and recruit beneficial microorganisms to suppress soilborne fungal pathogens and promote plant growth. Successive plantings dramatically enhanced disease suppression on susceptible wheat cultivars to AG8 in the greenhouse. Accordingly, analysis of the rhizosphere soil microbial community using deep sequencing of 16S rRNA genes revealed distinct bacterial community profiles assembled over successive wheat plantings. Moreover, the cluster of bacterial communities formed from the AG8-infected rhizosphere was distinct from those without AG8 infection. Interestingly, the bacterial communities from the rhizosphere with the lowest wheat root disease gradually separated from those with the worst wheat root disease over planting cycles. Successive monocultures and application of AG8 increased the abundance of some bacterial genera which have potential antagonistic activities, such as Chitinophaga, Pseudomonas, Chryseobacterium, and Flavobacterium, and a group of plant growth-promoting (PGP) and nitrogen-fixing microbes, including Pedobacter, Variovorax, and Rhizobium. Furthermore, 47 bacteria isolates belong to 35 species were isolated. Among them, eleven and five exhibited antagonistic activities to AG8 and Rhizoctonia oryzae in vitro, respectively. Notably, Janthinobacterium displayed broad antagonism against the soilborne pathogens Pythium ultimum, AG8, and R. oryzae in vitro, and disease suppressive activity to AG8 in soil. Conclusions: Our results demonstrated that successive wheat plantings and pathogen infection can shape the rhizosphere microbial communities and specifically accumulate a group of beneficial microbes. Our findings suggest that soil community selection may offer the potential for addressing agronomic concerns associated with plant diseases and crop productivity.

show abstract

Variovorax sp. Has an Optimum Cell Density to Fully Function as a Plant Growth Promoter

Cited by 17 publications

References 31 publications

Rhizosphere community selection reveals bacteria associated with reduced root disease

Rhizosphere community selection reveals bacteria associated with reduced root disease

Rhizosphere Community Selection Reveals Bacteria Associated With Reduced Root Disease

Rhizosphere community selection reveals bacteria associated with reduced root disease

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Variovorax sp. Has an Optimum Cell Density to Fully Function as a Plant Growth Promoter

Cited by 17 publications

References 31 publications

Rhizosphere community selection reveals bacteria associated with reduced root disease

Rhizosphere community selection reveals bacteria associated with reduced root disease

Rhizosphere Community Selection Reveals Bacteria Associated With Reduced Root Disease

Rhizosphere community selection reveals bacteria associated with reduced root disease&nbsp;

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Rhizosphere community selection reveals bacteria associated with reduced root disease