scholarly journals Indole-3-acetic acid (IAA) production trait, a useful screening to select endophytic and rhizosphere competent bacteria for rice growth promoting agents

MethodsX ◽  
2015 ◽  
Vol 2 ◽  
pp. 72-78 ◽  
Author(s):  
Hassan Etesami ◽  
Hossein Ali Alikhani ◽  
Hossein Mirseyed Hosseini
Author(s):  
Janardan Lamichhane ◽  
Bishnu Maya K.C. ◽  
Dhurva Prasad Gauchan ◽  
Sanjay Nath Khanal ◽  
Sharmila Chimouriya

Background: Indole-3-acetic acid (IAA), a principal phytohormone, controls several crucial physiological processes of plants. It ameliorates plant growth by stimulating cell elongation, root initiation, seed germination and seedling growth. Alteration of IAA level by plant growth promoting rhizobacteria leads to varied impacts on plant growth and development. Methods: Soil samples were collected from bamboo (Bambusa tulda, B. nutans subsp. cupulata, B. balcooa and Dendrocalamus strictus) rhizosphere. Altogether five bacterial isolates were screened by serial dilution method and subjected to biochemical analysis. The isolate BUX1 with high IAA production capacity was optimized for IAA production. IAA was partially purified and quantified from the bacterial extract by thin layer chromatography (TLC). The influence of extracted bacterial IAA on chlorophyll biosynthesis in bamboo seedlings of B. tulda was compared with uninoculated control plants. Results: Biochemical analysis revealed that all the isolates belonged to genus Bacillus which were found capable of producing IAA. During optimization, BUX1 isolate produced 99.13 µg ml-1 of IAA at 37°C, pH 7, 3 mg l-1 concentration of L-tryptophan and 150 rpm agitation rate after 192 hour of incubation. The Rf value of the bacterial IAA during TLC was identical to that of standard IAA (0.425) indicating that IAA was present in crude extract of Bacillus (BUX1). The influence of bacterial IAA on chlorophyll biosynthesis in bamboo seedlings was significant in comparison to uninoculated plants. Therefore, this isolate could be a prospective candidate to be employed as biofertilizer.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7258 ◽  
Author(s):  
Shabana Wagi ◽  
Ambreen Ahmed

Background Auxin production by bacteria is one of the most important direct mechanisms utilized by plant growth-promoting bacteria (PGPB) for the betterment of plants naturally because auxin is a plant friendly secondary metabolite synthesized naturally by bacteria, and hence improves the growth of associated plants. So, the current study focuses on bacterial synthesis of Indole-3-acetic acid (IAA) for plant growth improvement. Methods In the current study, the PGPB were selected on the basis of their auxin production potential and their growth promoting attributes were evaluated. Indole-3-acetic acid producing potential of two selected bacterial isolates was observed by varying different growth conditions i.e., media composition, carbon sources (glucose, sucrose and lactose) and different concentrations of precursor. Influence of various physiological factors (temperature and incubation time period) on IAA production potential was also evaluated. Results Both the bacterial strains Bacillus cereus (So3II) and B. subtilis (Mt3b) showed variable potential for the production of bacterial IAA under different set of growth and environmental conditions. Hence, the IAA production potential of the bacterial isolates can be enhanced by affecting optimum growth conditions for bacterial isolates and can be used for the optimal production of bacterial IAA and its utilization for plant growth improvement can lead to better yield in an eco-friendly manner.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Poovarasan Neelakandan ◽  
Chiu-Chung Young ◽  
Asif Hameed ◽  
Yu-Ning Wang ◽  
Kui-Nuo Chen ◽  
...  

AbstractTea leaves possess numerous volatile organic compounds (VOC) that contribute to tea’s characteristic aroma. Some components of tea VOC were known to exhibit antimicrobial activity; however, their impact on bacteria remains elusive. Here, we showed that the VOC of fresh aqueous tea leaf extract, recovered through hydrodistillation, promoted cell division and tryptophan-dependent indole-3-acetic acid (IAA) production in Pseudomonas sp. NEEL19, a solvent-tolerant isolate of the tea phylloplane. 1-octanol was identified as one of the responsible volatiles stimulating cell division, metabolic change, swimming motility, putative pili/nanowire formation and IAA production, through gas chromatography-mass spectrometry, microscopy and partition petri dish culture analyses. The bacterial metabolic responses including IAA production increased under 1-octanol vapor in a dose-dependent manner, whereas direct-contact in liquid culture failed to elicit such response. Thus, volatile 1-octanol emitting from tea leaves is a potential modulator of cell division, colonization and phytohormone production in NEEL19, possibly influencing the tea aroma.


2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Raúl Donoso ◽  
Pablo Leiva-Novoa ◽  
Ana Zúñiga ◽  
Tania Timmermann ◽  
Gonzalo Recabarren-Gajardo ◽  
...  

ABSTRACT Several bacteria use the plant hormone indole-3-acetic acid (IAA) as a sole carbon and energy source. A cluster of genes (named iac) encoding IAA degradation has been reported in Pseudomonas putida 1290, but the functions of these genes are not completely understood. The plant-growth-promoting rhizobacterium Paraburkholderia phytofirmans PsJN harbors iac gene homologues in its genome, but with a different gene organization and context than those of P. putida 1290. The iac gene functions enable P. phytofirmans to use IAA as a sole carbon and energy source. Employing a heterologous expression system approach, P. phytofirmans iac genes with previously undescribed functions were associated with specific biochemical steps. In addition, two uncharacterized genes, previously unreported in P. putida and found to be related to major facilitator and tautomerase superfamilies, are involved in removal of an IAA metabolite called dioxindole-3-acetate. Similar to the case in strain 1290, IAA degradation proceeds through catechol as intermediate, which is subsequently degraded by ortho-ring cleavage. A putative two-component regulatory system and a LysR-type regulator, which apparently respond to IAA and dioxindole-3-acetate, respectively, are involved in iac gene regulation in P. phytofirmans. These results provide new insights about unknown gene functions and complex regulatory mechanisms in IAA bacterial catabolism. IMPORTANCE This study describes indole-3-acetic acid (auxin phytohormone) degradation in the well-known betaproteobacterium P. phytofirmans PsJN and comprises a complete description of genes, some of them with previously unreported functions, and the general basis of their gene regulation. This work contributes to the understanding of how beneficial bacteria interact with plants, helping them to grow and/or to resist environmental stresses, through a complex set of molecular signals, in this case through degradation of a highly relevant plant hormone.


1996 ◽  
Vol 42 (6) ◽  
pp. 586-592 ◽  
Author(s):  
M. Brandi ◽  
E. M. Clark ◽  
S. E. Lindow

An epiphytic strain of Erwinia herbicola (strain 299R) synthesized indole-3-acetic acid (IAA) from indole-3-pyruvic acid and indole-3-acetaldehyde, but not from indole-3-acetamide and other intermediates of various IAA biosynthetic pathways in enzyme assays. TLC, HPLC, and GC–MS analyses revealed the presence of indole-3-pyruvic acid, indole-3-ethanol, and IAA in culture supernatants of strain 299R. Indole-3-acetaldehyde was detected in enzyme assays. Furthermore, strain 299R genomic DNA shared no homology with the iaaM and iaaH genes from Pseudomonas syringae pv. savastanoi, even in Southern hybridizations performed under low-stringency conditions. These observations strongly suggest that unlike gall-forming bacteria which can synthesize IAA by indole-3-acetamide, the indole-3-pyruvic acid pathway is the primary route for IAA biosynthesis in this plant-associated strain. IAA synthesis in tryptophan-supplemented cultures of strain 299R was over 10-fold higher under nitrogen-limiting conditions, indicating a possible role for IAA production by bacterial epiphytes in the acquisition of nutrients during growth in their natural habitat.Key words: indole-3-acetic acid, Erwinia, tryptophan, indole-3-pyruvic acid, nitrogen.


2004 ◽  
Vol 37 (9) ◽  
pp. 493-498 ◽  
Author(s):  
Ilse Y. Smets ◽  
Kristel Bernaerts ◽  
Astrid Cappuyns ◽  
Ositadinma Ona ◽  
Jos Vanderleyden ◽  
...  

1996 ◽  
Vol 42 (3) ◽  
pp. 279-283 ◽  
Author(s):  
T. C. Noel ◽  
C. Sheng ◽  
C. K. Yost ◽  
R. P. Pharis ◽  
M. F. Hynes

Early seedling root growth of the nonlegumes canola (Brassica campestris cv. Tobin, Brassica napus cv. Westar) and lettuce (Lactuca saliva cv. Grand Rapids) was significantly promoted by inoculation of seeds with certain strains of Rhizobium leguminosarum, including nitrogen- and nonnitrogen-fixing derivatives under gnotobiotic conditions. The growfh-promotive effect appears to be direct, with possible involvement of the plant growth regulators indole-3-acetic acid and cytokinin. Auxotrophic Rhizobium mutants requiring tryptophan or adenosine (precursors for indole-3-acetic acid and cytokinin synthesis, respectively) did not promote growth to the extent of the parent strain. The findings of this study demonstrate a new facet of the Rhizobium–plant relationship and that Rhizobium leguminosarum can be considered a plant growth-promoting rhizobacterium (PGPR).Key words: Rhizobium, plant growth-promoting rhizobacteria, PGPR, indole-3-acetic acid, cytokinin, roots, auxotrophic mutants.


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