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Date palm(Phoenix dactylifera)is commercially propagated through offshoots. Alongwith thisrooted offshootthe tree also produces aerial offshoots,which arerootlessand die after plantation. In this study attempts have been made to evaluate the effect of auxins on the root initiation of the aerial offshootsof date palm cv. Hillawi.Therefore, an experiment was conducted to evaluate theeffect of IAA (500 ppm), NAA(500 ppm), alone and in combination on root initiation in aerial offshoots of date palm cv. Hillawi. The auxins were applied to the aerial shoots by injection method. The experiment was laid out according to Randomized Complete Block Design (RCBD) with four treatments(Control, 500pmm IAA, 500ppm NAA and 500ppm IAA+NAA) andeach treatment was replicatedthrice.Injection method was used to apply the hormones and after the applicationof auxinsthe base of each offshoot was wrapped carefully with gunny bags having pinewood shaving as rooting media.After 40 days of supplication,offshootswere detached,and parameters were collected. Dataindicated that NAA @ 500ppm gave highest rooting percentage (24.5%), total number of roots per offshoot (82.33) and total weight of roots per offshoots (607.4g) as compared to other treatments. Similarly, a greaternumber of smaller roots (dia

The diversity of natural phytochemicals represents an unlimited source for discovery and development of new drugs. Ochradenus arabicus, (family: Resedaceae) a notable medicinal plant displays a high content of flavonoid glycosides. This study investigates a possible preventative role of zinc nanoparticles biosynthesized by O. arabicus leaf extracts (OAZnO NPs) in limiting genotoxicity and cytotoxicity caused by indole acetic acid (IAA) in laboratory mice. ZnO NPs were synthesized using O. arabicus leaf extracts and characterized with UV–visible spectroscopy, scanning electron microscopy (SEM) and X-Ray diffraction (XRD). The mice were randomly distributed into the following six groups: control, OAZnO NPs treated (10 mg/kg BW), IAA treated (50 mg/kg BW); simultaneous treatment, pre-treatment, and post-treatment. Reactive oxygen species (ROS), DNA damage, chromosome aberration, and apoptosis were analyzed as toxicity endpoints. IAA exposure significantly induced production of ROS, DNA damage, apoptosis, chromosome aberrations, and micronuclei. Pre-, post-, and simultaneous treatment with OAZnO NPs ameliorated the damage caused by IAA exposure. Exposure to OAZnO NPs alone caused no toxicity for any endpoint based on comparison to controls. This study demonstrated that IAA-induced cytotoxic damage in mice could be ameliorated by treatment with OAZnO NPs. These findings require additional verification in mechanistic and in vitro studies.

The study profiled the volatiles in Mentha longifolia, M. piperita and M. spicata and examined the effect of plant growth regulators (PGRs) - IAA, NaDK and SA on the modulations of volatile organic...

Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that stimulates and facilitates plant growth. The present work deals with the isolation, characterization, and identification of indole acetic acid-producing bacteria from the rhizospheric soil. Out of four organisms isolated from serial dilution, Sample-2 confirmed thick bands of IAA production by TLC analysis. 16s rRNA analysis showed the isolated organism was found to be Pseudomonas fluorescence with a similarity of 88%. The isolated organism treat plants showed increased shoot and root length in plant growth analysis. In conclusion, the isolated IAA-producing bacteria can be used as efficient biofertilizer inoculants to promote plant growth.

Background Environmental deterioration arising from the misuse of pesticides and chemical fertilizers in agriculture has resulted in the pursuit of eco-friendly means of growing crop. Evidence has shown that biofertilizers and biocontrol can boost soil fertility and suppress soil pathogens without compromising the safety of the environment. Hence, the study investigated the use of termitarium soil as a viable source for biofertilizer and biocontrol. Results Twenty-seven soil samples were collected from nine different mound soil (household, farm and water bodies in a sterile sample bag). Aliquots of serially diluted samples were plated on nutrient agar, plate count agar, eosin methylene blue agar and MacConkey agar plates. Isolates were identified using standard microbiological techniques. Identified isolates were screened for plant growth-promoting properties using phosphate solubilization test, potassium solubilization test and indole acetic acid production test. Activities of the plant growth-promoting bacteria were carried out using antagonism by diffusible substance method and antagonistic activity of cell-free culture filtrate of bacterial isolates against Ralstonia solanacearum and Fusarium oxysporum. Two hundred bacterial isolates were recovered from the 27 soil samples. The most predominant isolate was Bacillus spp. Out of the 200 bacterial isolates, 57 were positive for phosphate solubilization test, potassium solubilization test and indole acetic acid production test. Out of the 57 isolates, six bacterial isolates had antagonistic activities against Fusarium oxysporum, while seven bacterial isolates antagonized Ralstonia solanacearum. Conclusion The result showed that termite mound soil contains some useful bacteria that are capable of solubilizing phosphate and potassium and producing indole acetic acid which are the plant growth-promoting potentials and as well suppressing plant soil pathogen.

BackgroundSoil salinity has been one of the biggest hurdles in achieving better crop yield and quality. Plant growth-promoting rhizobacteria (PGPR) are the symbiotic heterogeneous bacteria that play an important role in the recycling of plant nutrients through phytostimulation and phytoremediation. In this study, bacterial isolates were isolated from salt-polluted soil of Jhajjar and Panipat districts of Haryana, India. The potential salt-tolerant bacteria were screened for their PGPR activities such as phosphate solubilization, hydrogen cyanide (HCN), indole acetic acid (IAA) and ammonia production. The molecular characterization of potent isolates with salt tolerance and PGPR activity was done by 16S rDNA sequencing.ResultsEighteen soil samples from saline soils of Haryana state were screened for salt-tolerant bacteria. The bacterial isolates were analyzed for salt tolerance ranging from 2 to 10%. Thirteen isolates were found salt tolerant at varied salt concentrations. Isolates HB6P2 and HB6J2 showed maximum tolerance to salts at 10% followed by HB4A1, HB4N3 and HB8P1. All the salt-tolerant bacterial isolates showed HCN production with maximum production by HB6J2. Phosphate solubilization was demonstrated by three isolates viz., HB4N3, HB6P2 and HB6J2. IAA production was maximum in HB4A1 (15.89) and HB6P2 (14.01) and least in HB4N3 (8.91). Ammonia production was maximum in HB6P2 (12.3) and least in HB8P1 (6.2). Three isolates HB6J2, HB8P1 and HB4N3 with significant salt tolerance, and PGPR ability were identified through sequencing of amplified 16SrRNA gene and were found to beBacillus paramycoides,Bacillus amyloliquefaciensandBacillus pumilus, respectively.ConclusionsThe salt-tolerant plant growth-promoting rhizobacteria (PGPR) isolated from saline soil can be used to overcome the detrimental effects of salt stress on plants, with beneficial effects of physiological functions of plants such as growth and yield, and overcome disease resistance. Therefore, application of microbial inoculants to alleviate stresses and enhance yield in plants could be a low cost and environmental friendly option for the management of saline soil for better crop productivity.

Indole acetic acid (IAA) can upregulate genes encoding enzymes responsible for the synthesis of carboxylates involved in phosphorus (P) solubilisation. Here, we investigated whether IAA and its precursor affect the P-solubilising activity of rhizobacteria. A total of 841 rhizobacteria were obtained using taxonomically selective and enrichment isolation methods. Phylogenetic analysis revealed 15 genera of phosphate solubilising bacteria (PSB) capable of producing a wide range of IAA concentrations between 4.1 and 67.2 µg mL−1 in vitro. Addition of l-tryptophan to growth media improved the P-solubilising activity of PSB that were able to produce IAA greater than 20 µg mL−1. This effect was connected to the drop of pH and release of a high concentration of carboxylates, comprising α-ketoglutarate, cis-aconitate, citrate, malate and succinate. An increase in production of organic acids rather than IAA production per se appears to result in the improved P solubilisation in PSB.

In Indonesia, synthetic chemical fertilizers are generally used to spur plant growth. The use of synthetic chemical fertilizers is known to reduce soil quality, causing resistance to pests and plant diseases. One of the natural potencies that can be used as growth promoters is Indole Acetic Acid (IAA) producing bacteria. The objective of this study was to measure the levels of Indole Acetic Acid (IAA) from the rhizosphere bacterial isolate of green beans which is thought to be able to produce Indole Acetic Acid (IAA). The method used was a descriptive approach, including the isolation of green bean rhizosphere bacteria, measurement of Indole Acetic Acid (IAA) levels in bacterial isolate, and data analysis. Green bean rhizosphere bacterial isolate produced Indole Acetic Acid (IAA) with an indication of a color change after the addition of the Salkowski reagent, and quantitatively the results of calculations in the standard curve equation for Indole Acetic Acid (IAA) obtained a value of Indole Acetic Acid (IAA) levels was 50.91 ppm.Keywords: Indole acetic acid, rhizosphere, bacteria

Aim: The present study was aimed to estimate the quantity of IAA production and Phosphate solubilisation by the isolated yeasts from the leguminous crops. Place and Duration of Work: The experiments were carried out in the Department of Agricultural Microbiology, University of Agricultural Sciences, GKVK, Bengaluru during 2019-2020. Methodology: Yeasts were isolated from the leguminous crops such as Red gram, Cowpea, Green gram, Black gram and Bengal gram. Thirty-five yeast isolates were obtained using four media and were subjected to IAA production test and Phosphorus solubilisation by Spectrophotometry method. All the yeast isolates were subjected to the temperature tolerance test at 25, 30, 35 and 40°C. Results: Yeast isolate, CP15SI21 has found to produce the highest IAA under in vitro conditions 30.50 μg/ml and the lowest was found to be 17.16μg/ml by yeast isolate BG20SI29. 24 yeast isolates were found to produce above 20 μg/ml. In the case of Phosphate solubilisation highest was observed in GG7SI9 (25.70 mg/l) and lowest in BG6SI8 (1.20 mg/l). Seven isolates showed Phosphate solubilisation above 10 mg/l. At 35°C all the yeast isolates have shown very good growth compared to other lower temperatures. All the yeast isolates were found to grow in the media supplemented with micronutrients such as zinc and potassium. Conclusion: Our study highlights the potential of yeasts isolated from the leguminous crops that can help in plant growth promotion as the yeast isolates are capable of producing higher amounts of IAA. Some of the yeast isolates can solubilise phosphate under in vitro conditions which in turn helps in the utilization of unavailable P from soils thereby improves plant growth and tolerance to a higher temperature can alleviate abiotic stress.

Background Antioxidants or vitamins are organic compounds that are needed in tiny quantities and have stimulatory role on growth and productivity of different plants. Two field experiments were conducted in two summer seasons to investigate the role of two irrigation systems (spraying and dripping) and α-tocopherol foliar treatment with different concentrations (0, 100 and 200 mg/L) on some growth indices and physiological aspects, yield and its components of sweet corn plants. Results The results show that dripping irrigation system was more effective than Sprinkler system on increasing the studied growth indices and biochemical attributes as well as yield quantity and quality. The results also show the enhancing effect of different α-tocopherol treatments on growth indices, and yield quantity and quality of the sweet corn varieties via enhancing photosynthetic pigments, indole acetic acid, phenolics, carbohydrates constituents, free amino acids and proline contents. Moreover, the interaction between the two irrigation systems and different concentrations α-tocopherol showed that, dripping irrigation with 200 mg/L α-tocopherol was the most effective treatment on increasing growth, yield and yield components of sweet corn plants. Conclusion It could be concluded that dripping irrigation system was more effective than Sprinkler system on increasing the studied growth indices and physiological aspects, yield and its constituents. Moreover, treatment of maize plant with α-tocopherol could improve the studied growth indices, physiological aspects and consequently yield.

The parasitic weed, Orobanche crenata, is one of the most devastating constraint for faba bean production in Mediterranean regions. Plant host defense induction was reported as one of the most appropriate control methods in many crops. The aim of this study was to elucidate the effect of salicylic acid (SA) and indole acetic acid (IAA) on the induction of faba bean resistance to O. crenata under the field and controlled experimental conditions. Both hormones were tested on two contrasting faba bean genotypes: Giza 843 (partially resistant to O. crenata) and Lobab (susceptible) at three different application methods (seed soaking, foliar spray, and the combination of both seed soaking and foliar spray). Soaking seeds in SA or IAA provided the highest protection levels reaching ~75% compared to the untreated control plants. Both elicitors limited the chlorophyll content decrease caused by O. crenata infestation and increased phenolic compound production in host plants. Phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activities were stimulated in the host plant roots especially in the susceptible genotype Lobab. The magnitude of induction was more obvious in infested than in non-infested plants. Histological study revealed that both SA and IAA decreased the number of attached O. crenata spikes which could be related to specific defense responses in the host plant roots.

BackgroundExogenous hormone applications modify the plant growth and development by inducing changes in their endogenous contents. However, it is not clear whether the effects of exogenous hormones on growth are direct or related with changes induced in endogenous hormones. Laboratory and greenhouse experiments were conducted to study the effect of exogenous salicylic acid (SA) or indole acetic acid (IAA) on endogenous levels in soaked seeds, 5-day-old seedlings, and in vegetative growth of foliar-sprayed plants. The effects of different concentrations of two hormones on germination and growth of maize were also studied.ResultsThe effect of presoaking maize seeds in solutions of SA or IAA (0, 0.25, 0.5, 1, and 2 mM) on their endogenous contents in soaked seeds or in 5-day-old seedlings. Soaked seeds absorbed more SA than IAA. In young seedlings, the majority of two hormones which absorbed during seed soaking remained in the residual seeds. Presoaking seeds in SA or IAA solutions suppressed the growth of 5-day-old seedlings. In the greenhouse experiment, endogenous SA and IAA increased after spraying two compounds at 0.25–2 mM, peaking 2 days after treatment then decreased on. However, plants treated with SA at 1 mM or 2 mM continued to pose higher levels of endogenous SA, 8 days later. At 20 days after treatments, all tested concentrations of two hormones significantly increased the fresh and dry weights of the whole plant. These inducing effects disappeared 40 days after spraying.ConclusionThe obtained results demonstrated the changes in endogenous SA and IAA in soaked seeds, seedling, and foliar-sprayed plants due to their exogenous application. However, concentrations of two hormones did not produce any permanent enhancement effects on germination and plant growth.

Background Kappaphycus alvarezii is the 5th world's most cultivated macroalgae, since it is an essential source of carrageenan, widely used in food industry. However, K. alvarezii is an unexplored biomass for green biorefinery conversion, since its composition includes valuable proteins, lipids, phenolic compounds, among others. Although there are reviews on K. Alvarezii cultivation and pharmacological properties, no information is available regarding extraction techniques applied to this algae biomass. Therefore, this review covers the lack of information on biorefinery concept applied to K. alvarezii and suggest sequential extractions to recover carrageenan and high-added value molecules by using non-conventional methods. Scope and approach This critical review presents the most recent data on K. alvarezii, including its scientific trends, production and potential. It also deals with non-traditional methods for sequential extractions applied to K. alvarezii. The search for available data was extended to the group of red algae to consider the concept of biorefinery. Key findings and conclusions K. alvarezii biomass can be used to obtain chlorophyll, β-carotene, essential amino acids (aspartic acid, glutamic acid and phenylalanine) and phytohormones (indole acetic acid, zeatin, kinetin and gibberellic acid). Therefore, we provide several sustainable insights to sequentially recovery carrageenan and other bioactive compounds from K. alvarezii.

Tiller angle, an important component of plant architecture, greatly influences the grain yield of rice (Oryza sativa L.). Here, we identified Tiller Angle Control 4 (TAC4) as a novel regulator of rice tiller angle. TAC4 encodes a plant‐specific, highly conserved nuclear protein. The loss of TAC4 function leads to a significant increase in the tiller angle. TAC4 can regulate rice shoot gravitropism by increasing the indole acetic acid content and affecting the auxin distribution. A sequence analysis revealed that TAC4 has undergone a bottleneck and become fixed in indica cultivars during domestication and improvement. Our findings facilitate an increased understanding of the regulatory mechanisms of tiller angle and also provide a potential gene resource for the improvement of rice plant architecture.

An efficient vegetative propagation method was developed for Hypericum gaitii. Indole-3-butyric acid (IBA), indole acetic acid, and naphthalene acetic acid in different concentrations and combinati...

Use of phosphate solubilizing bacteria (PSB) and rhizobia can have a positive effect on the growth of common bean. This study aimed at determining the mechanisms of action of native bacterial strains; and to determine their effect in enhancing growth of common bean. The strains were screened for their ability to solubilize insoluble inorganic phosphates and production of indole acetic acid in vitro. A greenhouse experiment was set up to evaluate the response of common bean to inoculation with selected bacterial strains. Six of the bacterial isolates tested showed a positive result for IAA production. Rhizobium pusense showed the greatest solubilization efficiency of 648 followed by Bacillus megaterium (322.3) and Rhizobium phaseoli (308.7). Inoculation of common bean with Rhizobia and PSB had a significant effect on the number of nodules per plant. The highest shoot biomass was observed when Rhizobium phaseoli was co-inoculated with P. polymyxa (4.3g plant-1) compared to the single Rhizobium phaseoli inoculation (1.14 g plant-1). The shoot tissue nitrogen and phosphorous concentration was increased as a results of co-inoculation up to 32.5% and 75.4% respectively. Therefore, tested bacterial strains have great potential in being formulated and used as biofertilizers that can be evaluated under varying field conditions.

Date palm is widely propagated through conventional offshoots. It is also produced through a tissue culture technique due to the limited number of offshoots produced throughout the course of a palm’s life. Being dioecious, it is a cross-pollinated tree that can be naturally or artificially pollinated. Tissue-cultured plants often have abnormal epigenetic or genetic changes that affect specific phenotypic characteristics. The growth of parthenocarpic fruits in date palms is mostly induced by hormonal imbalances in certain tissues. The major hormones in parthenocarpic fruits are auxins (IAA), gibberellins (GA3), and abscisic acid (ABA). Parthenocarpic, or abnormal fruit development, is an undesirable trait for date palm growers since it drastically reduces farm income. The current study was therefore conducted over two seasons to confirm previous observations and included conventional offshoot-derived trees (CO) and tissue culture-derived ones (TC) of the cultivar Barhee. According to the observed ratio of the fruiting abnormalities, two date palm tree ages were selected, i.e., 6 and 13 years. Two pollination interventions were used: pollination of naturally open female spathes (NOP) and pollination of forced open female spathes (FOP). Plant hormones, IAA, GA3, and ABA were identified just before pollination and at specific intervals after pollination for up to 85 days. The ratio of the abnormal fruit set was identified 5 days after pollination. Significant differences were observed in hormonal levels between tree ages as well as between tree propagation sources. Young TC trees (6-year-old) had high abnormal fruit sets compared to CO date palm trees that were the same age. During the early fruit growth and development phases, CO date palms had much higher amounts of IAA and GA3 than TC date palms. However, ABA concentrations were surprisingly higher in the TC trees during the early fruit growth stages, while it immediately decreased after pollination in the CO date palms. The ratio of abnormal fruits was significantly reduced in the 13-year-old TC date palms, and no differences were observed compared to the CO ones. The levels of IAA, GA3, and ABA hormones in both young and old date palms derived through CO or TC followed similar patterns. The critical observations regarding the ABA pattern in the old TC date palms (13-year-old) gradually dropped after pollination, which was identical to the CO ones, whereas it was the opposite in the young 6-year-old TC date palm plants.

The experiment was laid out to study the effect of pre-sowing treatments with growth regulators viz. Indole acetic acid (IAA), Salicylic acid (SA) and Gibberellin acid (GA3) with different concentrations like 50 ppm and 100 ppm on physiological and growth attributes of French bean. The seeds treated with growth regulators for 8 hrs. And 12 hrs. Duration along with three replications of treatments. The experimental approaches like plot size 2.5×2.5 m, spacing 45×15 cm and ridge & furrow planting method used and transplanting followed. The significantly maximum germination percentage (95.95%) recorded with 100 ppm concentration of IAA in this seeds soaked for 12 hrs. (T6) which was better over control (87.17%). The maximum change in seed diameter (0.86 cm) was noticed in T6 i.e. seeds treated with IAA 100 ppm concentration and soaked for 12 hrs. And minimum recorded in control (0 cm). The better length of radical (9.03 cm) when seeds treated with 100 ppm concentration of GA3 and soaked for 12 hrs. (T4). The minimum days taken to emergence (5.11 days) occurred with T6 i.e. seeds treated with 100 ppm IAA and soaked for 12 hrs. Over control. The results revealed that significant change in growth attributes of French bean like maximum plant height (66.46 cm), number of branches per plant (7.85), minimum days taken to 50% flowering (31.15 days) recorded when seeds treated with 100 ppm GA3 and soaked for 12 hrs. (T4) over control or water treated seeds.

Ginkgolide is one of the important secondary metabolites of Ginkgo biloba. The synthesis of plant secondary metabolites is influenced by exogenous phytohormones. In this study, ten-year-old ginkgo grafted seedlings were used as the test material, and the effects of 0, 2, 4, 6, 8, and 10 mmol L–1 gibberellin (GA3) on endogenous indole acetic acid (IAA), abscisic acid (ABA), GA3, and ginkgolide contents in ginkgo leaves were investigated. Results showed that exogenous GA3 treatment inhibited endogenous GA3, changed the contents of endogenous IAA and ABA in ginkgo leaves, and affected the accumulation of secondary metabolite ginkgolides. Among the given concentrations, the 4 mmol L–1 GA3 treatment could remarkably increase ginkgolide content. We found that the best harvesting period of ginkgo leaves were in late August and late September, in which the content of ginkgolides was the highest.

Phosphate-solubilizing microorganisms have been considered as a novel alternative approach to provide phosphate fertilizers that promote plant growth. In this study, three strains were isolated and identified as Penicillium oxalicum FJG21, Penicillium oxalicum FJQ5, and Bacillus subtilis BPM12, with a relatively high phosphate-solubilizing activity. Various phosphate sources were investigated, and Ca3(PO4)2 was identified as the effective phosphate source. Factors governing the phosphate-solubilizing activity of the strains included carbon and nitrogen sources, initial pH, and fermentation time. A high soluble phosphorus content was achieved with 529.0 μg·mL-1, 514.0 μg·mL-1, and 330.7 μg·mL-1 for Penicillium oxalicum FJG21, Penicillium oxalicum FJQ5, and Bacillus subtilis BPM12, respectively. An inverse correlation of the quantity of soluble phosphorus content and the pH value of the medium was observed. In addition, Bacillus subtilis BPM12 displayed a prominent capability of producing indole acetic acid. Penicillium oxalicum FJG21 and Penicillium oxalicum FJQ5 exhibited high cellulase activities. These phosphate-solubilizing microorganisms with good phosphate-solubilizing capability and growth-promoting ability are the promising strains for agricultural utilization.

To identify whether the auxin treatment could promote the growth and reduce the cadmium (Cd) of fruit trees, the effects of different concentrations of indole acetic acid (IAA, one of the auxin) on...

Aim: The presence of Phosphorus as a macronutrient in soil is necessary for plant growth and its deficiency restricts crop yield. Therefore, the aim of current study is to isolate promising rhizospheric phosphate solubilizing bacteria presenting with plant growth promoting (PGP) traits and their utilization as biofertilizers to improve Triticum aestivum (Var. Galaxy 2013) growth and nutrition. Method: Out of 30 isolates obtained from rhizosphere of various plants of different regions, 10 best PSRB strains (WumS-3, WumS-4, WumS-5, WumS-11, WumS-12, WumS-21, WumS-24, WumS-25, WumS-26 and WumS-28) were selected based on their high P solubilization and good PGP (auxin, psiderphore, HCN, Nitrogen fixation) activities. Triticum aestivum (Var. Galaxy 2013) was used as an experimental crop under laboratory and field conditions. Results: In this study, P solubilization capacity of selected strains were found 4–7 solubilization index on agar plate and 30–246 µg/ml in liquid broth respectively. The optimum conditions for phosphate solubilization under in vitro condition were found 35 °C at pH 7, glucose as good carbon source and ammonium nitrate as a good nitrogen source. Furthermore, the selected strains had the ability to produces phytohormones (indole acetic acid), siderophore, ammonia and Hydrogen Cyanide. Finally, PSRB inoculum showed significant (p

Due to over exploitation, the population of Eusideroxylon zwageri is decreasing drastically. One simple technique to conserve the last remaining genetic resources of E. zwageri is by air layering. The experiment was divided into two. The experiment was conducted from July 2018 to February 2019. The first experiment was conducted using branches that grew from coppices while the second experiment using twigs that grew from normal adult trees. Randomized Block Design was applied with three replicates. The treatments were consisted of nine concentration of auxin namely 0 ppm of auxin; 1, 000 ppm; 1,500 ppm; 2,000 ppm and 2,500 ppm of IAA and 1,000 ppm; 2,000 ppm; 3,000 ppm and 4,000 ppm of IBA. The result of experiment shows that the IBA growth regulator seems to be more effective in regulating growth and rooting of E. zwageri air layering compared to IAA. Results for air layering which was taken from coppices revealed that 1,000 ppm of IBA obtained the best results. Air layering of branches taken from coppice is possible even without any additional growth regulator. While, air layering of twigs which was taken from normal trees revealed that the best treatment is 3,000 ppm of IBA.

Lack of germination or low germination due to seed dormancy prevents successful crop establishment in several important plants. To determine the presence of innate seed dormancy and effects of stress-related plant hormones on germination performance of Teff (Eragrostis tef) seeds, we primed seeds in 1% KNO3 for 24 hours in dark conditions at 21 ± 0.5 ºC along with varying concentrations of chemicals known to influence seed germination, including: acetyl salicylic acid (ASA); methyl jasmonate (JA-Me); giberellic acid (GA3); and indole acetic acid (IAA). Primed seeds were incubated either in constant light (210 µM/m2/s) or in darkness at 21 ± 0.5 ºC. The results indicated that primingsignificantly improved final germination percentage (FGP) in both light (92.5%) and dark (89.4%) conditions compared with untreated seeds. The inclusion of plant hormones in the priming media generally had limited effects, except for 10 mM ASA (94.5%) and 100 mM GA3 (92.5%). ASA generally provided faster seed germination than seeds primed in 1% KNO3 only, while the other plant hormones had no effect on the time required for 50% of FGP in the dark. Priming had no significant effect on time span of germination in either light or dark incubation conditions. The results demonstrate that E. tef has light-inducible seed germination and about half of freshly harvested seeds can be dormant, which can be eliminated to some extent by priming seeds in 1% KNO3.

Endogenous chemicals specific to human metabolism have been suggested to be good candidates for markers of population size in wastewater-based epidemiology (WBE). So far, creatinine is the only endogenous chemical to be assessed against the criteria of in-sewer stability. This study thus aimed to evaluate the fate of three other endogenous compounds, 5-hydroxy indole acetic acid (5-HIAA), cortisol and androstenedione, under different sewer conditions using laboratory-scale sewer reactors. The results showed that while all compounds were stable in wastewater only (i.e. without biofilm), cortisol and androstenedione degraded quickly in sewers with the presence of sewer biofilms. The degradation followed first-order kinetics similar to that of creatinine. In contrast, 5-HIAA was relatively stable in sewer reactors. This study also recognised the impact of wastewater pH on the detectability of 5-HIAA using a LC-MS/MS direct injection method. In samples acidified to pH 2, the method did not allow routine detection/quantification of 5-HIAA whereas in non-acidified samples the method was sufficiently sensitive for routine quantification of 5-HIAA. The stability of 5-HIAA in sewers and the possibility to measure it using a simple and rapid analytical method corroborate that 5-HIAA may be a suitable biomarker for estimation of population size in WBE.

The potential of various genera and species of rhizosphere bacteria is well known. This study aims to determine the diversity and physiological characteristics of the rhizosphere bacterial isolates of oil palm plants at PTPN III Aek Nabara Labuhanbatu North Sumatra. This research was conducted in July 2018 to October 2018 in laboratory of STIPER Labuhanbatu. This research was conducted by isolating bacteria from the root rhizosphere of oil palm plants, characterizing the morphology and physiology of isolates by phosphate dissolution test and indole acetic acid production test. Furthermore, the data was analyzed descriptively. Based on the isolation results obtained 10 bacterial isolates with different macroscopic and microscopic morphological characteristics with the largest amount of dissolved phosphate produced by isolate R05 (0.211 mg / l) and the largest amount of IAA produced by isolate R04 (0.097 mg / l). Isolates R05 and R04 have the potential to be further tested.

The expression of drought responsive genes were enhanced by N application and they contributed to drought acclimation. The interactive effects of water and nutrient are crucial for plants. The aim of this study was to elucidate how nitrogen (N) status influence drought acclimation of Populus. A two-factorial design consisting of two N levels (adequate-N and low-N) and two watering treatments (drought stress and well-watered) was used, and an integrative investigation was conducted at the anatomical, physiological and molecular levels. Adequate N supply alleviated the adverse effects of drought stress on root growth in poplars, which may increase water uptake under drought. Nitrogen enhanced leaf anatomical changes and stomata adjustment upon drought stress, lead to less water losses and better growth performance under drought stress. The expression levels of phytohormone signaling components and genes responsible for antioxidative systems and secondary metabolites such as phenylpropanoids were promoted by N application. The expression of abscisic acid (ABA) signaling components was induced by drought when soil N was adequate, which participated in stomata regulation and drought acclimation. The expression of indole acetic acid (IAA) signaling components also was enhanced by N application, which participated in anatomical changes of leaves under drought. These adaptive changes at molecular and anatomical levels contributed to drought acclimation in a synergistic way. Under adequate-N condition, nitrogen and carbon metabolism pathways are being recruited to combat drought, and the C-N interaction play a pivotal role in drought acclimation.

Background: Heavy metals have their adverse effects on growth and physiology of plant. Plant growth regulators help in improving the growth and physiological phenomenon in plants. A pot culture experiment was devised to explore the ameliorative potential of Indole Acetic Acid (IAA) for toxicity of rhizospheric lead (Pb) on two varieties of Mung bean [Vigna radiate (L.) Wickzek]. Methods: Seeds of two varieties i.e., M- 8 and MN-92 were grown in earthen pots filled with sandy loam soil and were arranged under complete randomization. Fifteen days after germination, the lead (Pb) was added @ 10mg/kg and 20mg/kg soil as solution Pb NO3. Indole Acetic Acid @100.0mM was foliarly sprayed twice at 15 and 30 days of plants emergence. Physiological parameters i.e., Photosynthetic Rate, Transpiration Rate, Stomatal conductance, Sub Stomatal CO2 Concentration and biomass production in the form of stem, root and leaf dry weights were determined at the age of physiological maturity for three replicates. Result: By application of IAA, photostnthetic rate reduction was declined from 24.61% to 17.78% under 10mg Pb stress and from 55.54% to 27.35% under 20mg Pb stress. Stomatal conductance reduction was declined from 0.56% to 0.28% under 10mg Pb stress and from 3.37% to 1.68% under 20mg Pb stress. Alleviation of Pb stress by IAA for transpiration rate was non significant. Similarly, the role of IAA for alleviation of Pb stress in term of dry weights of stem,root and leaves were non significant statistically.

An Egyptian rhizobacterium Azospirillum sp. isolated from Sadat city was able to produce indole acetic acid (IAA) up to (30.59 µg/ml). The isolate was identified biochemically and by 16S rRNA sequencing which showed 99.9% similarity to Azospirillum brasilense. The new isolate has been registered in Genbank with accession number MH179119.1. Extracted IAA was used as reducing or stabilizing agent of sliver nanoparticles (AgNPs). Successful fabrication of biogenic IAA-AgNPs was confirmed by Fourier Transform Infrared Spectrophotometer (FTIR) analysis of IAA which showed absorbance peak at 3434.78 cm−1 due to the N-H stretch of primary amines. Highly resolution Transmission Electron Microscopy (HR-TEM) showed AgNPs coating or capping with IAA in spherical shaped with size ranged from 6.01 to 44.02 nm. Energy dispersive X-ray (EDX) analysis revealed that Ag+ ions were attached to the surface of IAA-AgNPs particles. HR-TEM examination showed cell wall damage of Citrobacter freundii cells after exposure to IAA-AgNPs leading to cell death. In vivo results showed that C. freundii infection of rats induced significant increase in liver and kidney functions and deleterious histopathological alteration in rat’s tissues. However, treatment by extracted IAA and IAA-AgNPs could normalize the biochemical and histopathological alterations occurred in infected rats. This is the first study to prove that IAA extracted from Azospirillum brasilense is a hopeful capping agent for NPs which has potential to protect against pathogenic infections, nontoxic and/or safe on rat’s metabolisms.

Hydroponic systems have gained interest and are increasingly used in hot and dry desert areas. Numbers of benefits are offered by hydroponic systems such as the ability to save water, enhance nutrients use efficiency, easy environmental control, and prevention of soil-borne diseases. However, the high consumption of chemical fertilizers for nutrient solution and the sensitivity of closed hydroponic systems to salinity are issues that need solutions. Thus, the main goal of our research activities is to isolate plant growth promoting fungi in order to develop sustainable hydroponic systems. We are working on isolating and testing the possibility to incorporate the cell-free filtrate (CFF) of plant growth promoting fungi (PGPF) in the composition of the nutrient solution. In this work, we isolated six strains of PGPF from the rhizosphere of the halophyte grass Aeluropus littoralis. Phylogenetic analyses of DNA sequences amplified by ITS1 and ITS4 primers identified the isolated fungi as: Byssochlamys spectabilis, Chaetomium globosum, Cephalotheca foveolata, Penicillium melinii, Alternaria tenuissima, and Nigrospora chinensis. The promoting of vigor in tobacco seedlings was used as criteria to evaluate the biostimulant activity of these fungi by adding either their mycelia (DE: direct effect) or their cell-free filtrates (CFF: indirect effect) to the plant-growth media. The best significant growth stimulation was obtained with plants treated by B. spectabilis. However, only the CFFs of Byssochlamys spectabilis (A5.1) and Penicillium melinii (A8) when added at a dilution factor of 1/50 to half-strength nutritive solution (0.5NS) resulted in significant improvement of all assessed growth parameters. Indeed, the A5.1CFF and A8CFF in 0.5NS induced a significant better increase in the biomass production when compared to NS or 0.5NS alone. All fungi produced indole acetic acid in the CFFs, which could be one of the key factors explaining their biostimulant activities. Furthermore, six genes involved in nitrogen-metabolism (NR1 and NRT1), auxin biosynthesis (Tryp1 and YUCCA6-like), and brassinosteroid biosynthesis (DET2 and DWF4) were shown to be induced in roots or leaves following treatment of plants with the all CFFs. This work opens up a prospect to study in deep the biostimulant activity of PGPFs and their applications to decrease the requirement of chemical fertilizers in the hydroponic growing systems.

Farming of barley and chickpea is nitrogen (N) fertilizer dependent. Using strategies that increase the nitrogen use efficiency (NUE) and its components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE) would reduce the N fertilizer application in the soil and its adverse environmental effects. We evaluated the effects of three different strains of diazotroph Klebsiella (K.p. SSN1, K.q. SGM81, and K.o. M5a1) to understand the role of biological nitrogen fixation (BNF) and bacterial indole-3-acetic acid (IAA) on NUE of the plants. A field study revealed that K.p. SSN1 results in profound increment of root surface area by eightfold and threefold compared to uninoculated (control) in barley and chickpea, respectively. We measured significant increase in the plant tissue nitrogen, chlorophyll content, protein content, nitrate reductase activity, and nitrate concentration in the inoculated plants (p ≤ 0.05). Treated barley and chickpea exhibited higher NUE and the components compared to the control plants (K.p. SSN1 ≥ K.q. SGM81&gt, K.o. M5a1). Specifically, K.q. SGM81 treatment in barley increased NUpE by 72%, while in chickpea, K.p. SSN1 increased it by 187%. The substantial improvement in the NUpE and NUE by the auxin producers K.p. SSN1 and K.q. SGM81 compared with non-auxin producer K.o. M5a1 was accompanied by an augmented root architecture suggesting larger contribution of IAA over marginal contribution of BNF in nitrogen acquisition from the soil.

Plant growth promoting rhizobacteria (PGPR) have critical role in promoting plant growth and health with various mechanisms. Production of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity are well-known plant growth promoting (PGP) properties. In the current study; A total of 48 morphologically distinct bacterial colonies were chosen during the isolation of bacteria from various rhizospheric wheat, maize and sainfoin soil samples from agricultural areas in Ağrı-Turkey. The bacteria were isolated from soil samples utilizing by culture-dependent techniques. Then, the strains were visualised for PGP activities such as production acetic acid IAA and ACC deaminase activity. The 16S rRNA sequence similarity of potential PGPR rhizospheric strains demonstrated that strains belong to species Bacillus, Pseudomonas, Microbacterium, Pseudarthrobacter, Arthrobacter and Enterobacter. Totally, 11 of 48 isolates exhibited highly IAA producing and ACC deaminase activity. These results show that IAA producing and ACC deaminase activity of local potential PGPR strains isolated from soil rhizospheric which can appropriate for sustainable agricultural applications in Ağrı province.

In the present study, 62 endophytic bacterial strains of cedar seeds (Cedrela odorata L.), collected in the municipalities of Huehuetán, Motozintla, and Pijijiapan in the state of Chiapas, Mexico were isolated. The goal was to identify characteristics of biotechnological interest such as biocontrol, promotion ofplant growth, and growth in aromatic compounds. The strains were identified by the partial sequence of the 16S ribosomal gene as belonging to the Bacillus genus. The biocontrol capacity of phytopathogenic fungi, production of indoleacetic acid (IAA), solubilization of phosphate, and growth in xenobiotic compounds (phenanthrene, benzene, anthracene, or phenol) were detected in 26 strains of the 62 isolates. 21 % of the strains inhibited the mycelial growth of Alternaria solani and Fusarium sp., and 13 % of the Phytophthora capsici oomycete. IAA production was detected in 24 isolates, phosphate solubilizing activity was identified in 18 isolates, while the ability to grow in the presence of phenanthrene and benzene was found in 26 isolates; 24 isolates grew in the presence of anthracene and only two isolates grew in phenol as the only carbon sources. This is the first report of the isolation and identification of endophytic bacteria from cedar seeds, where biotechnological characteristics were detected for biological control, promotion of plant growth, and growth in the presence of xenobiotic compounds. RESUMEN En el presente estudio se aislaron 62 cepas bacterianas endófitas de semillas de cedro (Cedrela odorata L.) colectadas en los municipios de Huehuetán, Motozintla y Pijijiapan en el estado de Chiapas, México, con el objetivo de identificar características de interés biotecnológicas como biocontrol, promoción del crecimiento vegetal y crecimiento en compuestos aromáticos. Las cepas se identificaron por la secuencia parcial del gen 16S ribosomal como pertenecientes al género Bacillus. En 26 cepas de las 62 aisladas se detectaron la capacidad de biocontrol de hongos fitopatógenos, la producción de ácido indolacético (AIA), la solubilización de fosfato y el crecimiento en compuestos xenobióticos (fenantreno, benceno, antraceno o fenol). El 21 % de las cepas inhibió el crecimiento miceliar de Alternaria solani y Fusarium sp., y el 13 % del oomiceto Phytophthora capsici. La producción de ácido indolacético se detectó en 24 aislados y la actividad solubilizadora de fosfato se encontró en 18 aislados, mientras que la capacidad de crecer en presencia de fenantreno y benceno se manifestó en 26 aislados (24 aislados crecieron en presencia de antraceno y solo dos aislados crecieron en fenol como únicas fuentes de carbono). Es importante mencionar que este es el primer reporte del aislamiento e identificación de bacterias endófitas de semillas de cedro, en el que se detectaron características biotecnológicas para el control biológico, la promoción del crecimiento vegetal y el crecimiento en presencia de compuestos xenobióticos.

This study aims to determine the formation and growth of stevia roots (Stevia rebaudiana Bertoni.) using Murashige and Skoog (MS) media on several concentration : Full MS, 1/2 MS and 1/4 MS and combined with several types of auxins: IAA (Indole Acetic Acid), NAA (Napthalene Acetic Acid) and IBA (Indole 3 Butyric Acid) in vitro. The research was carried out from June to November 2020 at the Tissue Culture Laboratory of the Department of Agricultural Production, Jember State Polytechnic. The study used a completely randomized factorial design with 2 factors. The first factor was 3 concentrations of MS media: ¼ MS; ½ MS; and MS Full. The second factor is the type of auxin:Control(Without Auxin), IAA, NAA and IBA. The three auxins use a concentration of 0.2 ppm. So that a total of 12 treatment combinations were repeated 5 times. So that we get 60 experimental units. The results showed that the MS concentration had a significant effect on root emergence, while for several types of auxins there was no significant difference in root emergence. The observation data also showed that the interaction between the concentration of MS media and the auxin hormone was not significantly different in stimulating the emergence of roots. At the end of the observation (30 DAP) the highest number of roots with an average of 4.23 was found in the NAA treatment with media modification of 1/2 MS.

Salinity stress causes a major threat to crops productivity across the globe. The effects of salt stress on photosynthetic pigments and minerals content were studied in this research work. The seeds of the two genotypes of okra (47-4 and LD 88) were pre-soaked in the solutions of IAA (0.4, 0.5, and 0.6 mM concentrations) and the seeds were sown in 10 kg of soil in polyethene bags already contained 0, 100, and 200 mM NaCl respectively. Salinity stress significantly reduced photosynthetic pigments and minerals content of the two genotypes of okra. Treatment of okra seeds with IAA at varying concentrations improved salt tolerance of the two genotypes, which is evident with increase photosynthetic pigments and minerals concentrations under salinity stress relatives to the negative control groups. Finally, we can infer from the results of this study that pre-soaked seeds with 0.4 mM IAA significantly ameliorated the effects of salinity on the two genotypes of okra, and this concentration could serve as a promising phytohormone for okra plant under moderate and severe salt levels.