• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.22-28
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• 2005

Gibberellins (GAs) play important roles in plant growth and development. Fifty-four fungi were isolated from the roots of 4 kinds of Sesamum indicum plants, and the production of GAs was spectrophotometrically examined. The number of GA-producing fungi was two strains from S. indicum, four strains from Gold S. indicum, and five strains from Brown S. indicum. Eleven fungi with GAs-producing activity were incubated for seven days in 40 ml of Czapek's liquid medium at $25^{\circ}C$ and 120 rpm, and the amount of each GA in the medium was measured by gas chromatographymass spectrometery (GC-MS). Penicillium commune KNU5379 produced more $GA_3$, $GA_4$, and $GA_7$ than Gibberella fujikuroi, Fusarium proliferatum, and Neurospora crassa which are known as GAs-producing fungi. GAs-producing activity of the P. commune KNU5379 was shown to produce 71.69 ng of $GA_1$, 252.42 ng of $GA_3$, 612.00 ng of $GA_4$, 259.00 ng of $GA_7$, and 202.69 ng of $GA_9$ in 25 ml of liquid medium. Bioassay of culture fluid of GA-producing fungi was also performed on rice sprout.

• 한국미생물·생명공학회지
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• 제35권4호
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• pp.357-363
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• 2007

249 fungal strains were isolated from the roots of 26 plants, and the production of GAs was spectrophotometric ally examined. As a result 76 fungal strains were shown to produce GAs. Bioassay of culture broth from seventy six fungal strains producing GAs was carried out with waito-c rice, that is dwarf rice. The seventy six fungi with GAs-producing activity were incubated for seven days in 40 mL of Czapek's liquid medium at $30^{\circ}C$ and 180 rpm, and the culture broth of fungi were treated on the 2-leaf rice sprout. Fifteen of these showed plant growth promoting activity and the amount of each GAs in the medium was measured by Gas chromatographymass spectrometer (GC-MS). Nine of these fungi were also identified by genetic analysis of the nucleotide sequences in the internal transcribed spacer region of the ribosomal DNA.

• 한국균학회지
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• 제32권1호
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• pp.16-22
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• 2004

Gibberellins(GAs)는 식물의 성장과 발전에 있어서 중요하게 작용한다고 알려져 있다. 따라서 본 연구에서는 농업과 원예분야에 매우 중요한 새로운 GAs 생성미생물을 탐색하고자 실험을 수행하였다. 생강나무(Lindera obtusiloba)와 산앵두나무(Vaccinium koreanum)의 뿌리에 존재하는 사상균을 분리하여 GAs 생산 활성을 측정하였으며, 비색법으로 GA 생산량을 분석하였을 때 이들 중에서 GAs 생산량이 가장 많은 것으로 확인된 두 균주에 대하여 여러 GAs 중에서 식물생장촉진 활성이 높다고 알려진 $GA_{1},\;GA_{3},\;GA_{4}$와 $GA_{7},\;GA_{53}$에 대하여 생산정도를 분석하고, 동정을 수행하였으며, Waito-c(난장이 볍씨)에서 Bioassay를 수행하였다. 생강나무에서는 6종의 균주, 산앵두나무에서는 4종류의 GAs 생산균을 분리하였고, 분리된 균중 GAs를 가장 많이 생산하는 균주들에 대하여 동정한 결과, 생강나무에서 분리한 C03 균주는 P. urticae KNUC03으로 동정되었으며, 산앵두나무에서 분리한 E03 균주는 P. griseofulvum KNUE03으로 동정되었다. 생합성된 GAs를 분석한 결과 P. urticae KNUC03 균주는 배양액 25 ml 중에 $GA_1\;7.08\;ng,\;GA_3\;30.80\;ng,\;GA_{4}\;1.27\;ng,\;GA_{7}\;0.88\;ng$ 및 $GA_{53}\;0.13\;ng$을 생산하였고 P. griseofulvum KNUE03은 $GA_1\;9.79\;ng,\;GA_3\;133.58\;ng,\;GA_4\;2.64\;ng,\;GA_7\;7.80\;ng$ 및 $GA_{53}\;0.73\;ng$을 생산하는 것이 확인되었다. 두 균주 중에서 P. griseofulvum KNUE03이 GAs를 더 많이 생산함을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.202-207
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• 2010

Plant growth promoting fungi (PGPF) are well known for the production of useful secondary metabolites. However, limited information is available on the gibberellin (GA) production capacity of PGPF of endophytic origin. In the current study, 15 fungal endophytes were isolated from the roots of Crown daisy, and then screened on Waito-c rice, in order to identify plant growth promoting fungi. The fungal isolate MH7 significantly increased the shoot length (12.1 cm) of Waito-c in comparison with control treatment (7.9 cm). In a separate experiment, the culture filtrate (CF) of MH7 significantly promoted the growth attributes of Crown daisy. The MH7 CF was analyzed for gibberellins and it contained all physiologically active gibberellins ($GA_1$, 1.37 ng/ml; $GA_3$, 5.88 ng/ml; $GA_4$, 8.62 ng/ml; and $GA_7$, 2.05 ng/ml) in conjunction with physiologically inactive $GA_9$ (0.83 ng/ml), $GA_{12}$ (0.44 ng/ml), $GA_{15}$ (0.74 ng/ml), $GA_{19}$ (1.16 ng/ml), and $GA_{20}$ (0.98 ng/ml). The CF of MH7 produced higher amounts of $GA_3$, $GA_4$, $GA_7$, $GA_9$, and $GA_{12}$ than wild-type Fusarium fujikuroi, which was used as a control for GA production. The fungal isolate MH7 was later identified as a new strain of Penicillium on the basis of its morphological characteristics and phylogenetic analysis of the 188 rDNA sequence.

• Mycobiology
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• 제43권1호
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• pp.87-91
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• 2015

Eighteen endophytic fungi with different colony morphologies were isolated from the roots of Nymphoides peltata growing in the Dalsung wetland. The fungal culture filtrates of the endophytic fungi were treated to Waito-c rice seedling to evaluate their plant growth-promoting activities. Culture filtrate of Y2H0002 fungal strain promoted the growth of the Waito-c rice seedlings. This strain was identified on the basis of sequences of the partial internal transcribed spacer region and the partial beta-tubulin gene. Upon chromatographic analysis of the culture filtrate of Y2H0002 strain, the gibberellins (GAs: $GA_1$, $GA_3$, and $GA_4$) were detected and quantified. Molecular and morphological studies identified the Y2H0002 strain as belonging to Aspergillus clavatus. These results indicated that A. clavatus improves the growth of plants and produces various GAs, and may participate in the growth of plants under diverse environmental conditions.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1744-1749
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• 2010

The role of endophytic fungi in plant growth and development is well documented. However, endophytic fungi with growth promotion capacity have never been isolated from weeds previously. In the current study, we isolated 8 fungal endophytes from the roots of Monochoria vaginalis, a serious weed of rice paddy in Korea. These isolates were screened on Waito-C, in order to identify plant growth promoting metabolites. Two fungal isolates (M5.A & M1.5) significantly promoted the plant height and shoot length of Waito-C during preliminary screening experiments. The culture filtrates (CFs) of M5.A and M1.5 also promoted the shoot length of Echinocloa crusgalli. Gibberellins (GAs) analysis of the CFs of M5.A and M1.5 showed that these endophytic fungi secrete higher quantities of GAs as compared with wild-type G. fujikuroi KCCM12329. The CF of M5.A contained bioactive GAs ($GA_3$, 2.8 ng/ml; $GA_4$, 2.6 ng/ml, and $GA_7$, 6.68 ng/ml) in conjunction with physiologically inactive $GA_9$ (1.61 ng/ml) and $GA_{24}$ (0.18 ng/ml). The CF of M1.5 contained physiologically active GAs ($GA_3$, 1.64 ng/ml; $GA_4$, 1.37 ng/ml and $GA_7$, 6.29 ng/ml) in conjunction with physiologically inactive $GA_9$ (3.44 ng/ml), $GA_{12}$ (0.3 ng/ml), and $GA_{24}$ (0.59 ng/ml). M5.A and M1.5 were identified as new strains of Penicillium sp. and Aspergillus sp., respectively, based on their 18S rDNA sequence homology and phylogenetic analysis.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.560-565
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• 2009

We isolated nine endophytic fungi from the roots of salt-stressed soybean cultivar Daewonkong and screened them for growth-promoting secondary metabolites. Of all fungal isolates, P-4-3 induced maximum growth promotion of waito-c rice and soybean. Analysis of the culture filtrate of P-4-3 showed the presence of physiologically active gibberellins $GA_1$, $GA_3$, $GA_4$, and $GA_7$, along with physiologically inactive $GA_{15}$ and $GA_{24}$. The plant growth promotion and gibberellin-producing capacity of P-4-3 was much higher than wild-type Gibberella fujikuroi, which was taken as the control during the present study. The fungal isolate P-4-3 was identified as a new strain of Scolecobasidium tshawytschae through the morphological characteristics and phylogenetic analysis of 18S rDNA sequence. Gibberellins production and plant growth promoting ability of genus Scolecobasidium was reported for the first time in the present study.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1549-1556
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• 2012

Endophytic fungi were isolated from roots of six halophytes in Suncheon Bay. The endophytic fungi of 35 species isolated from halophytes were identified by internal transcribed spacer (ITS) containing the ITS1, 5.8s, and ITS2 regions. All fungal strains were analyzed to diversity at the genus level. Fungal culture filtrates (FCF) of endophytic fungi were treated to Waito-c rice (WR) seedling for plant growth-promoting verification. It was confirmed that fungal strain Sj-2-2 provided plant growth promotion (PGP) to WR seedling. Then, PGP of Suaeda japonica was confirmed by treating culture filtrate of Sj-2-2. As a result, it was verified that culture filtrate of Sj-2-2 had more advanced PGP than positive control when treated to S. japonica. The secondary metabolites involved in culture filtrate of Sj-2-2 were identified by HPLC and GC-MS SIM analysis. The presence of physiologically bioactive gibberellins (GAs) and other inactive GAs in culture filtrate of Sj-2-2 was detected. The molecular analysis of sequences of Sj-2-2 showed the similarity to Penicillium sp. of 99% homology. The PGP of Sj-2-2 as well as symbiosis between endophytic fungi and halophytes growing naturally in salt marsh was confirmed. Sj-2-2 was identified as a new fungal strain producing GAs by molecular analysis of sequences. Consequently, the Sj-2-2 fungal strain was named as Penicillium sp. Sj-2-2. In this study, the diversity of endophytic fungi isolated from roots of halophytes in salt marsh and the PGP of a new gibberellin-producing fungal strain were confirmed.

• 한국균학회지
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• 제43권1호
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• pp.71-76
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• 2015

수생식물 샘플은 낙동강과 금호강이 만나는 달성습지에서 자라풀을 채집하였다. 자라풀의 뿌리에서 내생균류를 분리하고 형태가 다른 균주를 관찰하여 최종적으로 16개 균주를 선발하였다. 내생균류의 배양여과액은 식물생장촉진활성 검정을 위하여 난장이벼에 처리하여 스크리닝하였으며, HD1008 균주가 식물생장촉진활성이 가장 높은 것으로 확인되었다. HD1008 균주의 배양여과액을 HPLC와 GC/MS-SIM을 이용하여 분석하였고, HD1008 균주가 식물호르몬인 지베렐린 $GA_1$ (1.2 ng/100 mL)과 $GA_4$ (5 ng/100 mL) 를 생산하는 것을 정량분석을 통하여 확인하였다. 또한, HD1008균주의 beta-tubulin 유전자 염기서열을 이용하여 동정에 이용하였으며, 분자적인 방법과 형태적인 방법으로 관찰하였을 때, 지베렐린을 생산하는 새로운 P. trzebinskii로 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1244-1249
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• 2009

Endophytic fungi are known for the production of valuable metabolites, but information on the gibberellin production capacity of this group is limited. We isolated 9 endophytic fungi from the roots of salt-stressed soybean plants and screened them on waito-c rice, in order to identify plant growth promoting fungal strains. The fungal isolate TK-2-4 gave maximum plant length (20.35 cm) promotion in comparison with wild-type Gibberella fujikuroi (19.5 cm). In a separate experiment, bioassay of TK-2-4 promoted plant length and biomass of soybean cultivar Taegwangkong. The TK-2-4 culture filtrate was analyzed for the presence of gibberellins, and it was found that all physiologically active gibberellins, especially $GA_4$ and $GA_7$, were present in higher amounts ($GA_1$, 0.11 ng/ml; $GA_3$, 2.91 ng/ml; $GA_4$, 3.21 ng/ml; and $GA_7$, 1.4 ng/ml) in conjunction with physiologically inactive $GA_9$ (0.05 ng/ml), $GA_{12}$ (0.23 ng/ ml), $GA_{15}$ (0.42 ng/ml), $GA_{19}$ (0.53 ng/ml), and $GA_{20}$ (0.06 ng/ml). The fungal isolate TK-2-4 was later identified as a new strain of Phoma herbarum, through the phylogenetic analysis of 28S rDNA sequence.