Primera evidencia de actividad enzimática nitrilasa en Xylaria sp., y su relación con la biosíntesis de ácido indol-3-acético / First evidence of nitrilase enzymatic activity of Xylaria sp. and its relationship with the biosynthesis of indole-3-acetic acid

Resumen Muchos de los hongos degradadores de madera están implicados en la síntesis de metabolitos bioactivos de naturaleza antimicrobiana y terapéutica, así como de compuestos de importancia biotecnológica, incluyendo derivados indólicos, entre otros. Estos hongos brindan ciertos beneficios ecológicos a las plantas, entre los que se destacan la protección contra fitopatógenos y la promoción del crecimiento radicular. Xylaria sp. es un hongo degradador de celulosa (lignocelulolítico) con potencial biotecnológico. El ácido indol-3-acético (AIA) desempeña un papel sumamente importante en las interacciones planta-microorganismo, ya que es esencial para la fisiología y el correcto desarrollo morfológico vegetal. Se sabe que las enzimas nitrilo-hidrolíticas (nitrilasas) están involucradas en la síntesis de compuestos indólicos en las plantas, no obstante, se dispone de poca información acerca de la naturaleza de estas enzimas en el reino de los hongos. A través de una aproximación bioquímica y de genética molecular, se demuestra por primera vez que Xylaria sp. posee actividad enzimática nitrilasa utilizando compuestos ricos en nitrógeno y carbono como sustrato. La cepa estudiada aumentó sus niveles de expresión génica relativa y mostró crecimiento micelial, ambos en presencia de compuestos químicos como cianobenceno y KCN. Los resultados de este trabajo sugieren que el microorganismo es capaz de degradar moléculas nitrogenadas complejas. Por otra parte, mediante biofertilización con extractos fúngicos, se observó que Xylaria sp. promueve el desarrollo del sistema radicular de plántulas de Arabidopsis thaliana, además de sintetizar AIA.

Abstract Endophytic fungi inhabit plant tissues internally and asymptomatically, and many of them are involved in the synthesis of bioactive metabolites of antifungal and therapeutic nature, as well as other compounds of biotechnological importance including indole derivatives, among many others. Ecologically, they provide some benefits to plants including protection against phy-topathogens and promotion of root growth. In this sense, Xylaria sp. is a cellulose-decomposing fungus with biotechnological potential. It is worth mentioning that indole-3-acetic acid (IAA) also plays an extremely important role in plant-micro-organism interactions, as it is essential for physiology and proper plant morphological development. It is known that nitrile-hydrolytic enzymes (nitrilases) are involved in the synthesis of plant indole compounds; however, relatively little information is available concerning the nature of these enzymes in the fungal kingdom. In view of the above, through a biochemical and molecular-genetic approach, it has been demon-strated for the first time that Xylaria sp. carries out nitrile-hydrolytic enzyme activity using nitrogen and carbonrich compounds as substrate. The studied strain increased its relative gene expression levels and showed mycelial growth, both in the presence of chemical compounds such as cyanobenzene and KCN. Thus, the results of this work suggest that the micro-organism is capable of degrading complex nitrogenous molecules. On the other hand, through fungal biofertilization, it was observed that Xylaria sp. promotes the development of the root system of Arabidopsis thaliana seedlings, in addition to synthesizing IAA.

Genome analysis and plant growth promoting activity of Pseudonocardia strain DR1-2 from the root of Dendrobium christyanum Rchb.f

Aims@#The objective of this study was to analyze the genome of endophytic actinomycete associated with orchids and evaluate its plant hormone activities, including phytohormone, siderophore, ammonia production, zinc and phosphate solubilization.@*Methodology and results@#Strain DR1-2 isolated from the roots of the Thai orchid, Dendrobium christyanum Rchb.f., was closely related to Pseudonocardia alni DSM 44104T, P. antarctica DSM 44749T and P. carboxydivorans Y8T (99.93-100% similarity) based 16S rRNA gene sequence. This strain exhibited IAA production (294.10 ± 12.17 μg/mL), phosphate solubilization (2.20 ± 0.08 solubilization Index, SI), positive for siderophore production and ammonia production (36.99 ± 2.24 μg/mL). It showed a maximum IAA of 489.73 ± 8.90 μg/mL, when optimized using 0.5% Ltryptophan, pH 6 and incubated at 30 °C for 7 days. The IAA of strain enhanced the root length, shoot length, number of roots and fresh weight of rice seedlings (Oryza sativa L. cv. RD49). The draft genome of strain DR1-2 was 6,077,423 bp in 23 contigs with G+C content of 74.6%. The average nucleotide identity-Blast (ANIb) and average nucleotide identity-MUMmer (ANIm) values of strain DR1-2 and related type strains were 95.81 to 97.25% and the digital DNA-DNA hybridization (dDDH) values were 72.60 to 74.00%, respectively. Genomic analysis of strain DR1-2 revealed that the gene encodes the enzyme involved in the phytohormones biosynthesis and gene clusters involved in the biosynthesis of bioactive metabolites.@*Conclusion, significance and impact of study@#Endophytic actinomycete, Pseudonocardia strain DR1-2 from Thai orchid, D. christyanum Rchb.f., exhibited significant IAA production and affected the growth of the plant, which was the potential source of plant hormones for agricultural applications.

Identification and characterization of plant growth-promoting properties of bacterial endophytes from selected Zingiberaceae plants

Aims@#This study aims to isolate, characterize and screen the plant growth-promoting bacteria from Zingiberaceae plants. Plant promoting activities such as indole-3-acetic acid (IAA), phosphate solubilization, zinc solubilization and nitrogen-fixing capabilities are determined, and the IAA production of selected isolates are optimized. @*Methodology and results@#Endophytic bacteria were isolated from the plant samples by surface sterilization on nutrient agar (NA) plates and incubated at 30 °C for 2-3 days. The bacteria were identified based on their phenotypic characteristics and 16S rRNA gene sequence analyses. All isolates were identified as genera Bacillus, Lysinibacillus, Kerstersia, Klebsiella and Brucella. The isolates exhibited phosphate solubilization (1.5 ± 0.75-37.5 ± 8.75 Solubilization Index, SI), zinc solubilization (2.5 ± 0-60 ± 1.5 SI) and IAA production (0.1 ± 0.2-115.7 ± 1.6 µg/mL), while 3 isolates possessed nitrogen-fixing capabilities. Five isolates (PHAS-2, PWS-2, PWR-2, PHBS-2 and SCG-2) were selected for IAA optimization. Isolate PWR-2 produced the maximum IAA at 447.7 ± 0 µg/mL when tryptophan concentration was maintained at 1.0%.@*Conclusion, significance and impact of study@#Genera of bacteria included Bacillus, Lysinibacillus, Kerstersia, Klebsiella and Brucella were successfully isolated from Zingiberaceae plants. All the isolates showed the capability to produce IAA, while some isolates exhibited phosphate solubilization and zinc solubilization, and a few possessed nitrogen-fixing capabilities. The potential IAA production isolates could be applied for the enhancement of agricultural production that will be becoming a more widely accepted practice.

Characterization of indole-3-acetic acid in cambial zone tissue by ultra-performance liquid chromatography-tandem mass spectrometry

The developmental plasticity of plants according to changes in their growth conditions is mediated by signalingmolecules called hormones. The major classes of plant hormones are auxin, gibberellins, abscisic acid, andethylene. Among these, the most important is indole-3-acetic acid (IAA). Quantification of IAA in an extract ofapproximately 10 mg obtained from the cambial zone of Eucalyptus leaves was performed by ultra-performanceliquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS). Theleaves were extracted using acetone, and the extract was analyzed using a reverse-phase column (Acquity UPLCBEH C18, 2.1 mm × 100 mm, 1.7 µm) at a flow rate of 0.2 mL/min with gradient elution of an aqueous mobile phase(containing 0.1% formic acid) with methanol. This gradient elution provided an excellent performance in terms ofspecificity/selectivity, linearity, precision, and ruggedness/stability. In addition, the run time was short (6 min), withexcellent linearity (R2 > 0.99) in the range of 10–70 ng/mL. The structure of IAA was elucidated using UPLC/ESIMS/MS, operating and quantifying in multiple reaction monitoring (MRM) mode.

Screening of plant growth promoting rhizobacteria for antifungal activity against Fusarium oxysporum

Aim: New species of Plant Growth Promoting Rhizobacteria (PGPR), with varying growth promoting and biocontrol ability are often being discovered. They facilitate plant growth either directly by secreting nutrients and hormones or indirectly by providing defence mechanism to the plant. The present study was undertaken to isolate PGPR from the rhizosphere of Solanum lycopersicum and Arachis hypogaea, and test their growth promoting ability and antifungal activity against Fusarium oxysporum. Methodology: PGPRs were isolated from the rhizosphere of S. lycopersicum and A. hypogaea by serial dilution of the rhizospheric soil and identified by 16s rDNA sequencing. The isolates were analysed for antifungal activity against F. oxysporum, indole 3-acetic acid (IAA) production and phosphate solubilisation. For the growth promotion assay, aseptically grown Vigna radiata seedlings were dipped separately in isolated bacterial suspension of PGPR (109 CFU ml-1) and planted in autoclaved soil. Plants were irrigated with 50% Hoagland solution for every 48 hr and maintained at 25 ± 2 °C with 16/8 hr of light and dark photoperiod. Growth promotion was examined in terms of differences in shoot length, root length, fresh weight and dry weight after 12 days of treatment. Results: Six isolates were found to have antifungal activity towards plant pathogen, F. oxysporum. Five isolates showed similarity to Pseudomonas aeruginosa (B7-1, B11-5, B3-1, Rh-1, Rh-2) and one to Pseudomonas putida (B53). All six strains were able to produce IAA, where B53 and B13-1 showed the highest production compared to other strains. P. putida B53 demonstrated the highest plant growth promotion activity by significantly (p<0.05) increasing the growth of V. radiata plants as evidenced by increase in shoot length, root length, fresh and dry weight. Interpretation: The results obtained from the present study supports that PGPRs like Pseudomonas sp. could serve as potential eco-friendly bio-fertilizer and bio- fungicide

Isolation and identification by 16S rRNA sequence analysis of plant growth-promoting azospirilla from the rhizosphere of wheat

ABSTRACT The main objective of the present study was to isolate phytohormone-producing, phosphate-solubilizing strains of Azospirillum from wheat to be used as inoculants for plant growth promotion. Five Azospirillum strains were isolated from the rhizosphere of field-grown wheat (Triticum aestivum L.), and it was confirmed by BOX-polymerase chain reaction (PCR) that the isolates were different and not re-isolates of the same strain. Sequence analysis of the PCR-amplified 16S rRNA gene indicated that four isolates showed maximum similarity to Azospirillum brasilense and one isolate showed maximum similarity to Azospirillum zeae. This is the first report indicating the presence of an A. zeae like isolate in the wheat rhizosphere in Pakistan. The bacterial isolates were characterized for their plant growth-promoting traits, phosphate solubilization, and indole-3-acetic acid (IAA) production. None of the isolates showed phosphate solubilization activity in the commonly used Pikovskaya medium. However, all strains (except AzoK4) exhibited ability to solubilize tricalcium phosphate (TCP) in modified Pikovskaya medium in which sucrose was replaced by Na-malate, as well as in TCP-supplemented Luria-Bertani (LB) medium. Organic acids, such as acetic, citric, lactic, malic, and succinic acids, were detected in culture supernatants of the tested Azospirillum strains. All strains exhibited ability to produce IAA in the growth medium, except Azospirillum sp. AzoK1. Among the strains tested, the maximum IAA production (30.49 ± 1.04 mg L-1) and phosphate solubilization (105.50 ± 4.93 mg L-1) were shown by a pure culture of Azospirillum sp. AzoK2. In pot experiments, single-strain inocula of Azospirillum sp. AzoK1 and AzoK2 improved wheat plant growth.

Indole acetic acid and ACC deaminase from endophytic bacteria improves the growth of Solarium lycopersicum

Background: Endophytic bacteria are ubiquitous in all plant species contributing in host plant's nutrient uptake and helping the host to improve its growth. Moringa peregrina which is a medicinal plant, growing in arid region of Arabia, was assessed for the presence of endophytic bacterial strains. Results: PCR amplification and sequencing of 16S rRNA of bacterial endophytes revealed the 5 endophytic bacteria, in which 2 strains were from Sphingomonas sp.; 2 strains from Bacillus sp. and 1 from Methylobacterium genus. Among the endophytic bacterial strains, a strain of Bacillus subtilis LK14 has shown significant prospects in phosphate solubilization (clearing zone of 56.71 mm after 5 d), ACC deaminase (448.3 ± 2.91 nM α-ketobutyrate mg-1 h-1) and acid phosphatase activity (8.4 ± 1.2 nM mg-1 min-1). The endophytic bacteria were also assessed for their potential to produce indole-3-acetic acid (IAA). Among isolated strains, the initial spectrophotometry analysis showed significantly higher IAA production by Bacillus subtilis LK14. The diurnal production of IAA was quantified using multiple reactions monitoring method in UPLC/MS-MS. The analysis showed that LK14 produced the highest (8.7 uM) IAA on 14th d of growth. Looking at LK14 potentials, it was applied to Solanum lycopersicum, where it significantly increased the shoot and root biomass and chlorophyll (a and b) contents as compared to control plants. Conclusion: The study concludes that using endophytic bacterial strains can be bio-prospective for plant growth promotion, which might be an ideal strategy for improving growth of crops in marginal lands.

Contribution of the IAM Pathway to IAA Pool in Developing Rice Grains

A possible role for the indole-3-acetamide (IAM) pathway in the indole-3-acetic acid (IAA) production was investigated in developing rice grains. IAM-hydrolase proposed to convert IAM to IAA primarily through the identification of IAM and IAM-hydrolase activity in some plant species. Expression profiles of the two putative rice IAM-hydrolase genes, OsAMI1&2, were compared to the previously quantified IAA level. The abrupt increase in IAA level between 4 and 7 days after anthesis (DAF) was not found to correlate with changes in the expression of OsAMI1 or OsAMID2 suggesting that the IAM pathway may not contribute significantly to IAA pool in rice grains. Production of a biological compound other than IAA may explain the high activity of OsAMI1&2 in developing rice grains. OsAMI1 that reported to be conserved across the plant kingdom showed higher expression level in most analyzed reproductive rice tissues whereas OsAMID2 showed more fluctuation in expression comparing to OsAMI1. Role of the IAM pathway in IAA production was also discussed in other plant systems and Arabidopsis seed was recommended as an ideal tissue to identify enzyme(s) convert(s) tryptophan to IAM as well as physiological effects of IAA produced via this pathway.

Determination of Related Substance in Indometacin Enteric-coated Tablet by Improving HPLC / 中国药房

OBJECTIVE:To improve HPLC for the contents determination of 2-methyl-5-methoxy-indole-3-acetic acid(impuri-ty Ⅰ) and 4-chlorobenzoic (impurity Ⅱ) in Indometacin enteric-coated tablet. METHODS:The column was Phenomenex Phe-nyl-Hexyl with mobile phase of 10 g/L acetic acid solution- acetonitrile(gradient elution)at a flow rate of 1.0 ml/min,the detec-tion wavelength was 254 nm,column temperature was 40℃,injection volume was 20 μl. RESULTS:The linear range was 0.262 2-5.243 0 μg/ml for impurity Ⅰ(r=0.999 8)and 0.252 5-5.050 0 μg/ml for impurity Ⅱ(r=0.999 8);the limits of quanti-tation were 1.12 ng and 0.48 ng,limits of detection were 0.340 ng and 0.146 ng,respectively;RSDs of precision,stability and re-producibility tests were lower than 2%;recoveries were 99.71%-100.52%(RSD=0.28%,n=9) and 100.84%-102.14%(RSD=0.47%,n=9). CONCLUSIONS:The method is accurate and rapid,and can be used for the contents determination of impurity Ⅰand impurityⅡin Indometacin enteric-coated tablet.

The morphology and bioactivity of the rice field cyanobacterium Leptolyngbya / Morfología y bioactividad de la cianobacteria Leptolyngbya en los campos de cultivo de arroz

The genus Leptolyngbya comprises filamentous cyanobacteria that are important in rice fields. In the rhizosphere, cyanobacteria produce a variety of secondary metabolites such as auxins that are important in agriculture soil performance. To assess this, Leptolyngbya strain MMG-1, was isolated from the rhizosphere of rice plants and described. For this, the morphology of this strain was studied by light microscopy as well as by confocal laser scanning microscopy. Besides, the ability of this strain to synthesize an auxin-like bioactive compound was demonstrated under various culture conditions (different amounts of tryptophan; pH; different alternating light:dark periods; duration of the incubation). The auxin-like compound was extracted from the culture of Leptolyngbya strain MMG-1 and identified as indole-3-acetic acid (IAA) by thin layer chromatography (TLC) as well as by high performance liquid chromatography (HPLC). Our results showed that the strain required the precursor L-tryptophan for the synthesis of IAA. Leptolyngbya strain MMG-1 accumulated IAA intracellularly. The IAA secreted by Leptolyngbya strain MMG-1 was significantly correlated with the initial concentration of L-tryptophan in the medium, as well as with the duration of the incubation. The bioactivity of the secreted IAA was determined by its effect on the rooting pattern of Pisum sativum seedlings. The culture supernatant of Leptolyngbya strain MMG-1 stimulated the seedling lateral rooting, while it decreased root length. Hence, rhizospheric Leptolyngbya produced auxin under different conditions and affected the plants rooting pattern. Rev. Biol. Trop. 62 (3): 1251-1260. Epub 2014 September 01.

El género Leptolyngbya comprende cianobacterias filamentosas que son importantes en los campos de cultivo de arroz. En la rizosfera, las cianobacterias producen una variedad de metabolitos secundarios, tales como auxinas, que son importantes en el rendimiento de la agricultura del suelo. La cepa Leptolyngbya MMG-1, fue aislada de la rizosfera de plantas de arroz y se describe en este trabajo. La morfología de esta cepa se estudió por microscopía de luz, así como por microscopía confocal de barrido láser. Además, se estimó la capacidad de esta cepa para sintetizar el compuesto bioactivo auxina como se demostró en diversas condiciones de cultivo (diferentes cantidades de triptófano; pH; diferente luz alterna: períodos oscuros; duración de la incubación). La auxina se extrajo a partir del cultivo de la cepa Leptolyngbya MMG-1 y se identificó como ácido indol-3-acético (AA) por cromatografía de capa fina (TLC), así como por cromatografía líquida de alta resolución (HPLC). Nuestros resultados mostraron que la cepa requiere el precursor de L-triptófano para la síntesis de IAA. La cepa Leptolyngbya MMG-1 acumula intracelularmente IAA. El IAA secretada por la cepa Leptolyngbya MMG-1 se correlacionó significativamente con la concentración inicial de L-triptófano en el medio, así como con la duración de la incubación. La bioactividad de la IAA secretada se determinó por su efecto sobre el patrón de enraizamiento de plantas de semillero de Pisum sativum. El sobrenadante del cultivo de la cepa Leptolyngbya MMG-1 estimuló el enraizamiento lateral en la plántula, mientras que se redujo la longitud de la raíz. Por lo tanto, la producción de auxina por Leptolyngbya rizosférica afectó el crecimiento de las plantas.

In Vitro Regeneration from Shoot Tip and Nodal Explants of Simarouba Glauca DC, a Promising Biodiesel Tree.

An efficient regeneration protocol was developed from shoot tip and nodal explants of Simarouba glauca DC, a promising biodiesel plant. Nodal explants appeared to have better regeneration capacity than shoot tip explants (40%) in the tested media. The highest regeneration frequency (90%) and shoot number (7.00 ± 1.00 shoots per explants) were obtained in nodal explants in Murashige and Skoog’s (MS) medium supplemented with 6-benzylaminopurine (BAP) 4.43 μM and α-naphthalene acetic acid (NAA) 5.36 μM.Induced shoot buds were multiplied and elongated on the MS medium supplemented with BAP (4.44 μM), NAA (5.36 μM) and TDZ (Thidiazuron) 2.27 μM with 9.66±0.33 (mean length 5.35±0.32 cm) and 9.00±0.57 (mean length 4.51±0.15cm) shoots using nodal segments and shoot tip explants, respectively. Halfstrength woody plant medium (WPM) containing 2.46μM indole-3-butyric acid (IBA) produced the maximum number of roots (6.00±1.15). The rooted plantlets were hardened on MS basal liquid medium and subsequently in polycups containing sterile soil and vermiculite (1:1) and successfully established in pots.

The Effect of Photodynamic Therapy Using Indole-3-Acetic Acid and Green Light on Acne Vulgaris

BACKGROUND: Photodynamic therapy (PDT) using topical aminolevulinic acid (ALA) has increasingly been used for the treatment of acne vulgaris and several studies have shown its clinical efficacy. However, ALA-PDT needs a relatively long incubation period and is frequently associated with adverse effects. Indole-3-acetic acid (IAA) has been introduced as a new photosensitizer for the treatment of acne in recent study. IAA-PDT requires only a short incubation period and the procedure is relatively painless in contrast to ALA-PDT. OBJECTIVE: To investigate the efficacy and safety of IAA- PDT in the treatment of acne. METHODS: Twenty-five patients with facial acne lesions were enrolled in this study. IAA-PDT was performed for five sessions at 1-week intervals (week 0~4). IAA was treated with 15 minute occlusion, and green light was given for 15 minutes. Clinical efficacy was determined by evaluating acne lesion counts, severity grading, and the Dermatology Life Quality Index (DLQI) at week 0, 2, 4, and 5. Sebum secretion and erythema index was measured by Sebumeter and Mexameter, respectively, at baseline and one week after each treatment session (week 1~5). Histopathological examination was performed at baseline and week 5. Adverse effects were recorded throughout the study. RESULTS: All the patients completed the study. Numbers of both inflammatory and non-inflammatory acne lesions were significantly decreased. Acne severity grade and the DLQI showed significant reduction. Sebum secretion and erythema were also reduced. Histopathological examination showed a reduction in inflammatory reactions. No adverse effects were observed except for transient pruritus in one patient. CONCLUSION: PDT using IAA and green light was an effective, simple and safe treatment for acne.

Variable responses on early development of shallot (Allium ascalonicum) and mustard (Brassica juncea) plants to Bacillus cereus inoculation

Aim: Auxin, a phytohormone secreted by plant growth-promoting rhizobacteria is one of the direct mechanisms vital for plant growth promotion. A laboratory experiment was conducted to observe the effect of IAA-producing and non-IAA-producing diazotroph Bacillus cereus strains on early growth of shallot (Allium ascalonicum) and mustard (Brassica juncea) plants. Methodology and Results: Treatments evaluated were as follows: Control = uninoculated, no inoculation, UPMLH1 = IAA-producing B. cereus UPMLH1, and UPMLH24 = non-IAA-producing B. cereus UPMLH24. Inoculation with IAA-producing B. cereus UPMLH1 significantly increased shallot adventitious roots (root number and length) and shoot growth (19 to 54% increment). Inoculation of non-IAA-producing B. cereus UPMLH24 did not significantly improve growth of adventitious roots of shallot as compared to uninoculated control, except its shoot (up to 40% increase). However, primary roots and shoot growth of mustard plants significantly increased through inoculation with IAA-producing and non-IAA-producing strains (14 to 73% increment). Conclusion, Significance and Impact of Study: The results indicated that exogenous IAA secreted by B. cereus UPMLH1 might have play an important role in inducing roots of shallot bulbs and it may have a variable promotional effect depending on plant species.

A simple and rapid plate assay for the screening of Indole-3-Acetic Acid (IAA) producing microorganisms.

The indole-3-acetic acid (IAA) producing plant growth promoting rhizobacteria (PGPR) are routinely screened in the laboratory by colorimetric method in culture supernatant which is time consuming and expensive. We developed a novel plate assay for the detection of IAA in the bacterial strains. This method is rapid, cheap and accurate for IAA production in microorganisms.

Effects of exogenous hormones on growth and tanshinones accumulation in radix of Salvia miltiorrhiza / 中草药

Objective To study the effects of exogenous hormones,gibberellin(GA3)and indole-3-acetic acid(IAA),on growth and tanshinones accumulation in the radix of Salvia miltiorrhiza.MethodsThe herb characters and contents of tanshinones(cryptotanshinone,tanshinone Ⅰ,and tanshinone ⅡA)in the radix of S.miltiorrhiza with different hormone treatments were investigated and compared in the combination of trail pot and indoor analysis.Results It promoted aboveground biomass in the radix of S.miltiorrhiza increasing with single GA3.But it inhibited underground biomass increasing.The exogenous addition of low-level and high-level GA3 was benefit for tanshinones accumulation,whereas the middle-level GA3 wasn't.The aboveground and underground biomass in the radix of S.miltiorrhiza increased indistinctively with the increasing of IAA concentration and then decreased.And the IAA solutions also increased plant height and root length indistinctively.in a whole,it was benefit for tanshinones accumulation when applying low-level IAA(0.5 mg/L)singly.With the increasing of IAA concentration,the content of cryptotanshinone increased,but the contents of tanshinone Ⅰ and tanshinone ⅡA decreased.It promoted S.miltiorrhiza radix growth and three tanshinones contents increasing obviously with the combined application of two low-level hormones.Conclusion The applying of GA3 and IAA is benefit for the growth and three tanshinones accumulation in the radix of S.miltiorrhiza.