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Characterization of Plant Growth–Promoting Traits of Bacteria Isolated from Larval Guts of Diamondback Moth Plutella xylostella (Lepidoptera: Plutellidae)

Department of Agricultural Chemistry, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju, 361763, Republic of Korea.
Current Microbiology (Impact Factor: 1.42). 05/2008; 56(4):327-33. DOI: 10.1007/s00284-007-9086-4
Source: PubMed

ABSTRACT

Eight bacterial isolates from the larval guts of Diamondback moths (Plutella xylostella) were tested for their plant growth-promoting (PGP) traits and effects on early plant growth. All of the strains tested positive for nitrogen fixation and indole 3-acetic acid (IAA) and salicylic acid production but negative for hydrogen cyanide and pectinase production. In addition, five of the isolates exhibited significant levels of tricalcium phosphate and zinc oxide solubilization; six isolates were able to oxidize sulfur in growth media; and four isolates tested positive for chitinase and beta-1,3-glucanase activities. Based on their IAA production, six strains including four that were 1-aminocyclopropane-1-carboxylate (ACC) deaminase positive and two that were ACC deaminase negative were tested for PGP activity on the early growth of canola and tomato seeds under gnotobiotic conditions. Acinetobacter sp. PSGB04 significantly increased root length (41%), seedling vigor, and dry biomass (30%) of the canola test plants, whereas Pseudomonas sp. PRGB06 inhibited the mycelial growth of Botrytis cinerea, Colletotrichum coccodes, C. gleospoiroides, Rhizoctonia solani, and Sclerotia sclerotiorum under in vitro conditions. A significant increase, greater than that of the control, was also noted for growth parameters of the tomato test plants when the seeds were treated with PRGB06. Therefore, the results of the present study suggest that bacteria associated with insect larval guts possess PGP traits and positively influence plant growth. Therefore, insect gut bacteria as effective PGP agents represent an unexplored niche and may broaden the spectrum of beneficial bacteria available for crop production.

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Available from: Rangasamy Anandham, Sep 02, 2015
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    • "Bacteria are reported to have the ability to produce low-molecular weight siderophores that are capable of sequestering Fe 3? and to help plants to have their iron requirement. Siderophores act as solubilizing agents of iron from minerals under conditions of iron limitation (Indiragandhi et al. 2008). Siderophores are reported to form stable complexes with heavy metals such as Al, Cd, Cu, Ga, In, Np, Pb, U and Zn and increase the soluble metal concentration (Rajkumar et al. 2010). "
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    • "ACC deaminase, IAA, siderophore Poonguzhali et al. (2008) Serratia marcescens IAA, siderophore, HCN Selvakumar et al. (2008) Pseudomonas fluorescens ACC deaminase, phosphate solubilization Shaharoona et al. (2008) Acinetobacter sp., Pseudomonas sp. ACC deaminase, IAA, antifungal activity, N 2 -fixation, phosphate solubilization Indiragandhi et al. (2008) Enterobacter sp. ACC deaminase, IAA, siderophore, phosphate solubilization Kumar et al. (2008) Burkholderia ACC deaminase, IAA, siderophore, heavy metal solubilization, phosphate solubilization Jiang et al. (2008) Pseudomonas jessenii ACC deaminase, IAA, siderophore, heavy metal solubilization, phosphate solubilization Rajkumar and Freitas (2008) Pseudomonas aeruginosa ACC deaminase, IAA, siderophore, phosphate solubilization Ganesan (2008) ACC: 1-aminocyclopropane-1-carboxylate; EPS: exopolysaccharides; IAA: indole acetic acid. "
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    • "IAA producing bacteria are known to stimulate seed germination, initiate lateral and adventitious root formation and increase root surface area and length thereby provides the host plant greater access to water and soil nutrients (Ahemad and Kibret 2014). Siderophores act as solubilizing agents for iron from minerals under conditions of iron limitation (Indiragandhi et al. 2008). In addition, siderophores form stable complexes with heavy metals, including U, Np, Al, Cu, Cd, In, Ga, Zn, and Pb and increases the soluble metal concentration (Rajkumar et al. 2010), thus, it help to alleviate the stresses imposed on plants by heavy metals in soils. "
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