The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Douglas B Noltie - One of the best experts on this subject based on the ideXlab platform.
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migratory dynamics of stream spawning longnose Gar lepisosteus osseus
Ecology of Freshwater Fish, 1996Co-Authors: B. L. Johnson, Douglas B NoltieAbstract:Abstract– Literature evidence suggests that lake-dwelling longnose Gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose Gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose Gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose Gar disperse from the spawning stream great distances, with Gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.
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Migratory dynamics of stream‐spawning longnose Gar (Lepisosteus osseus)
Ecology of Freshwater Fish, 1996Co-Authors: B. L. Johnson, Douglas B NoltieAbstract:Abstract– Literature evidence suggests that lake-dwelling longnose Gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose Gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose Gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose Gar disperse from the spawning stream great distances, with Gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.
B. L. Johnson - One of the best experts on this subject based on the ideXlab platform.
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migratory dynamics of stream spawning longnose Gar lepisosteus osseus
Ecology of Freshwater Fish, 1996Co-Authors: B. L. Johnson, Douglas B NoltieAbstract:Abstract– Literature evidence suggests that lake-dwelling longnose Gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose Gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose Gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose Gar disperse from the spawning stream great distances, with Gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.
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Migratory dynamics of stream‐spawning longnose Gar (Lepisosteus osseus)
Ecology of Freshwater Fish, 1996Co-Authors: B. L. Johnson, Douglas B NoltieAbstract:Abstract– Literature evidence suggests that lake-dwelling longnose Gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose Gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose Gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose Gar disperse from the spawning stream great distances, with Gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.
In-jung Lee - One of the best experts on this subject based on the ideXlab platform.
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shoot elongation and gibberellin contents in cyclamen persicum are influenced by temperature and light intensity
Horticulture Environment and Biotechnology, 2015Co-Authors: Jiseon Kim, In-jung Lee, Yoonha Kim, Ki Sun KimAbstract:Elongated petioles and wide leaf laminas decrease the ornamental quality of potted cyclamen (Cyclamen persicum). We determined the relationship between leaf petiole elongation and lamina expansion and endogenous gibberellins (GAs) of cyclamen as influenced by light intensity, daily light integral (DLI), and temperature. ‘Metis Scarlet Red’ cyclamen plants with five fully unfolded leaves were cultivated in growth chambers maintained at 14°C (low temperature, LT) and 26°C (high temperature, HT) and illuminated at 60 and 240 µmol·m-2·s-1 PPF [(low light (LL) and high light (HL), respectively] with 8 h (short day, SD) and 16 h (long day, LD) photoperiods by fluorescent lamps, giving a total of eight treatments. HT and LL increased petiole length, plant height, and leaf size. There was no significant effect of photoperiod on plant height or petiole length. ‘Metis Scarlet Red’ cyclamen had GA1 and GA4 as active GAs with a similar concentration. The concentration of active GAs was higher in plants grown at the HT compared to the LT. Concentrations of GA20 and GA1, products in the early C-13-hydroxylation pathway, and GA9 and GA4, products of the non C-13-hydroxylation pathway, were higher in plants grown under LL than HL. Petiole length increased linearly by about 6 cm (200%) in all eight treatments as the concentration of active GAs (GA1 + GA4) increased from 12 to 34 ng·g-1. These results indicate that temperature and DLI regulated petiole length of cyclamen by controlling the content of active GAs.
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endophytes aspergillus caespitosus lk12 and phoma sp lk13 of moringa peregrina produce gibberellins and improve rice plant growth
Journal of Plant Interactions, 2014Co-Authors: Abdul Latif Khan, Muhammad Waqas, Javid Hussain, Ahmed Alharrasi, Ahmed Alrawahi, Khadija Alhosni, Minji Kim, Muhammad Adnan, In-jung LeeAbstract:Two new strains of endophytic fungi were isolated from the bark of Moringa peregrina and identified as Aspergillus caespitosus LK12 and Phoma sp. LK13. These endophytes were identified through amplifying polymerase chain reaction (PCR) and sequencing the 18S internal transcribed spacer of DNA extracted from both endophytes. Pure cultures of endophytic fungi were subjected to extract and isolate gibberellins (GAs). Deuterated standards of [17,17-2H2]-GA1, [17,17-2H2]-GA3, [17, 17-2H2]-GA4 and [17, 17-2H2]-GA7 were used to quantify the endophytic fungal GAs. The analysis revealed that both the endophytes are producing bioactive GAs in various quantities (ng mL−1). A. caespitosus LK12 was producing GA1 (54.51 ± 1.23), GA4 (26.5 ± 0.65), and GA7 (2.87 ± 1.23) while Phoma sp. LK13 was secreting GA1 (4.8 ± 0.12), GA3 (8.65 ± 0.21), GA4 (23.7 ± 0.98), and GA7 (22.7 ± 0.73). The culture filtrate (CF) of A. caespitosus and Phoma sp. significantly increased the shoot length of GAs-deficient mutant waito-c and norma...
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endophytic fungi produce gibberellins and indoleacetic acid and promotes host plant growth during stress
Molecules, 2012Co-Authors: Muhammad Waqas, Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Yoonha Kim, Muhammad Kamran, In-jung LeeAbstract:We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs) and indoleacetic acid (IAA) and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7) in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.
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endophytic fungal association via gibberellins and indole acetic acid can improve plant growth under abiotic stress an example of paecilomyces formosus lhl10
BMC Microbiology, 2012Co-Authors: Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Yoonha Kim, Heeyoung Jung, Joonghwan Lee, In-jung LeeAbstract:Endophytic fungi are little known for exogenous secretion of phytohormones and mitigation of salinity stress, which is a major limiting factor for agriculture production worldwide. Current study was designed to isolate phytohormone producing endophytic fungus from the roots of cucumber plant and identify its role in plant growth and stress tolerance under saline conditions. We isolated nine endophytic fungi from the roots of cucumber plant and screened their culture filtrates (CF) on gibberellins (GAs) deficient mutant rice cultivar Waito-C and normal GAs biosynthesis rice cultivar Dongjin-byeo. The CF of a fungal isolate CSH-6H significantly increased the growth of Waito-C and Dongjin-byeo seedlings as compared to control. Analysis of the CF showed presence of GAs (GA1, GA3, GA4, GA8, GA9, GA12, GA20 and GA24) and indole acetic acid. The endophyte CSH-6H was identified as a strain of Paecilomyces formosus LHL10 on the basis of phylogenetic analysis of ITS sequence similarity. Under salinity stress, P. formosus inoculation significantly enhanced cucumber shoot length and allied growth characteristics as compared to non-inoculated control plants. The hypha of P. formosus was also observed in the cortical and pericycle regions of the host-plant roots and was successfully re-isolated using PCR techniques. P. formosus association counteracted the adverse effects of salinity by accumulating proline and antioxidants and maintaining plant water potential. Thus the electrolytic leakage and membrane damage to the cucumber plants was reduced in the association of endophyte. Reduced content of stress responsive abscisic acid suggest lesser stress convened to endophyte-associated plants. On contrary, elevated endogenous GAs (GA3, GA4, GA12 and GA20) contents in endophyte-associated cucumber plants evidenced salinity stress modulation. The results reveal that mutualistic interactions of phytohormones secreting endophytic fungi can ameliorate host plant growth and alleviate adverse effects of salt stress. Such fungal strain could be used for further field trials to improve agricultural productivity under saline conditions.
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Gibberellin producing Neosartorya sp. CC8 reprograms Chinese cabbage to higher growth
Scientia Horticulturae, 2011Co-Authors: Muhammad Hamayun, Nadeem Ahmad, Sumera Afzal Khan, Abdul Latif Khan, Yasmin Nawaz, Hasan Sher, In-jung LeeAbstract:Abstract Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0 cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA1 and GA4 contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA1, 1.42 ng/ml; GA3, 5.93 ng/ml; GA4, 11.36 ng/ml; GA7, 3.25 ng/ml; GA9, 0.79 ng/ml; GA15, 1.18 ng/ml). The culture filtrate of CC-8 produced higher amounts of GA3, GA4, GA7 and GA9 than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques.
Abdul Latif Khan - One of the best experts on this subject based on the ideXlab platform.
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endophytes aspergillus caespitosus lk12 and phoma sp lk13 of moringa peregrina produce gibberellins and improve rice plant growth
Journal of Plant Interactions, 2014Co-Authors: Abdul Latif Khan, Muhammad Waqas, Javid Hussain, Ahmed Alharrasi, Ahmed Alrawahi, Khadija Alhosni, Minji Kim, Muhammad Adnan, In-jung LeeAbstract:Two new strains of endophytic fungi were isolated from the bark of Moringa peregrina and identified as Aspergillus caespitosus LK12 and Phoma sp. LK13. These endophytes were identified through amplifying polymerase chain reaction (PCR) and sequencing the 18S internal transcribed spacer of DNA extracted from both endophytes. Pure cultures of endophytic fungi were subjected to extract and isolate gibberellins (GAs). Deuterated standards of [17,17-2H2]-GA1, [17,17-2H2]-GA3, [17, 17-2H2]-GA4 and [17, 17-2H2]-GA7 were used to quantify the endophytic fungal GAs. The analysis revealed that both the endophytes are producing bioactive GAs in various quantities (ng mL−1). A. caespitosus LK12 was producing GA1 (54.51 ± 1.23), GA4 (26.5 ± 0.65), and GA7 (2.87 ± 1.23) while Phoma sp. LK13 was secreting GA1 (4.8 ± 0.12), GA3 (8.65 ± 0.21), GA4 (23.7 ± 0.98), and GA7 (22.7 ± 0.73). The culture filtrate (CF) of A. caespitosus and Phoma sp. significantly increased the shoot length of GAs-deficient mutant waito-c and norma...
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endophytic fungi produce gibberellins and indoleacetic acid and promotes host plant growth during stress
Molecules, 2012Co-Authors: Muhammad Waqas, Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Yoonha Kim, Muhammad Kamran, In-jung LeeAbstract:We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs) and indoleacetic acid (IAA) and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7) in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.
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endophytic fungal association via gibberellins and indole acetic acid can improve plant growth under abiotic stress an example of paecilomyces formosus lhl10
BMC Microbiology, 2012Co-Authors: Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Yoonha Kim, Heeyoung Jung, Joonghwan Lee, In-jung LeeAbstract:Endophytic fungi are little known for exogenous secretion of phytohormones and mitigation of salinity stress, which is a major limiting factor for agriculture production worldwide. Current study was designed to isolate phytohormone producing endophytic fungus from the roots of cucumber plant and identify its role in plant growth and stress tolerance under saline conditions. We isolated nine endophytic fungi from the roots of cucumber plant and screened their culture filtrates (CF) on gibberellins (GAs) deficient mutant rice cultivar Waito-C and normal GAs biosynthesis rice cultivar Dongjin-byeo. The CF of a fungal isolate CSH-6H significantly increased the growth of Waito-C and Dongjin-byeo seedlings as compared to control. Analysis of the CF showed presence of GAs (GA1, GA3, GA4, GA8, GA9, GA12, GA20 and GA24) and indole acetic acid. The endophyte CSH-6H was identified as a strain of Paecilomyces formosus LHL10 on the basis of phylogenetic analysis of ITS sequence similarity. Under salinity stress, P. formosus inoculation significantly enhanced cucumber shoot length and allied growth characteristics as compared to non-inoculated control plants. The hypha of P. formosus was also observed in the cortical and pericycle regions of the host-plant roots and was successfully re-isolated using PCR techniques. P. formosus association counteracted the adverse effects of salinity by accumulating proline and antioxidants and maintaining plant water potential. Thus the electrolytic leakage and membrane damage to the cucumber plants was reduced in the association of endophyte. Reduced content of stress responsive abscisic acid suggest lesser stress convened to endophyte-associated plants. On contrary, elevated endogenous GAs (GA3, GA4, GA12 and GA20) contents in endophyte-associated cucumber plants evidenced salinity stress modulation. The results reveal that mutualistic interactions of phytohormones secreting endophytic fungi can ameliorate host plant growth and alleviate adverse effects of salt stress. Such fungal strain could be used for further field trials to improve agricultural productivity under saline conditions.
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exophiala sp lhl08 reprograms cucumis sativus to higher growth under abiotic stresses
Physiologia Plantarum, 2011Co-Authors: Muhammad Hamayun, Nadeem Ahmad, Abdul Latif Khan, Muhammad Waqas, Sang-mo KangAbstract:Endophytic fungi are potential sources of secondary metabolites; however, they are little known for phytohormones secretion and amelioration of plant growth under abiotic stresses. We isolated a novel endophyte from the roots of Cucumis sativus and identified it as a strain of Exophiala sp. by sequencing internal transcribed spacer/large subunit rDNA and phylogenetic analysis. Prior to identification, culture filtrate (CF) of Exophiala sp. has shown significant growth promotion of Waito-C [a gibberellins (GAs)-deficient mutant cultivar] and Dongjin-byeo (normal GAs biosynthesis cultivar) rice seedlings. CF analysis of Exophiala sp. showed the presence of physiologically active GAs (GA1, GA3, GA4 and GA7) and inactive GAs (GA5, GA8, GA9, GA12 and GA20). Exophiala sp. had higher GAs in its CF than wild-type strain of Gibberella fujikuroi except GA3. Influence of Exophiala sp. was assessed on cucumber plant's growth and endogenous abscisic acid (ABA), salicylic acid (SA) and bioactive GAs under salinity and drought stresses. Exophiala sp.-treated plants have shown significantly higher growth and rescued the host plants from stress promulgated water deficit, osmotic and cellular damage. The altered levels of stress-responsive ABA showed low level of stress confined to endophyte-applied plants than control. Elevated levels of SA and bioactive GAs (GA3 and GA4) in endophyte-associated plants suggest stress-modulating response toward salinity and drought. In conclusion, symbiotic relations between Exophiala and cucumber have reprogrammed the host plant growth under abiotic stresses, thus indicating a possible threshold role of endophytic fungi in stress alleviation. This study could be extended for improving agricultural productivity under extreme environmental conditions.
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Gibberellin producing Neosartorya sp. CC8 reprograms Chinese cabbage to higher growth
Scientia Horticulturae, 2011Co-Authors: Muhammad Hamayun, Nadeem Ahmad, Sumera Afzal Khan, Abdul Latif Khan, Yasmin Nawaz, Hasan Sher, In-jung LeeAbstract:Abstract Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0 cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA1 and GA4 contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA1, 1.42 ng/ml; GA3, 5.93 ng/ml; GA4, 11.36 ng/ml; GA7, 3.25 ng/ml; GA9, 0.79 ng/ml; GA15, 1.18 ng/ml). The culture filtrate of CC-8 produced higher amounts of GA3, GA4, GA7 and GA9 than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques.
Sang-mo Kang - One of the best experts on this subject based on the ideXlab platform.
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Expression of gibberellin 2-oxidase 4 from Arabidopsis under the control of a senescence-associated promoter results in a dominant semi-dwarf plant with normal flowering
Journal of Plant Biology, 2014Co-Authors: Hyung Jin Na, Sang-mo Kang, Hyung-woo Jeon, Phi Yen Le, Jae-heung KoAbstract:Gibberellin (GA), a plant hormone, is involved in many aspects of plant growth and development both in vegetative and reproductive phases. GA2-oxidase plays a key role in the GA catabolic pathway to reduce bioactive GAs. We produced transgenic Arabidopsis plants expressing GA2-oxidase 4 ( AtGA2ox4 ) under the control of a senescenceassociated promoter ( SEN1 ). As we hypothesized, transgenic plants ( SEN1::AtGA2ox4 ) exhibited a dominant semi-dwarf phenotype with a decrease of bioactive GAs (e.g., GA4 and GA1) up to two-fold compared to control plants. Application of bioactive GA3 resulted in increased shoot length, indicating that the GA signaling pathway functions normally in the SEN1::AtGA2ox4 plants. Expressions of other members of GA2-oxidase family, such as AtGA2ox1, AtGA2ox3, AtGA2ox6 , and AtGA2ox8 , were decreased slightly in the flower and silique tissues while GA biosynthetic genes (e.g., AtGA20ox1, AtGA20ox2 and AtGA3ox1 ) were not significantly changed in the SEN::AtGA2ox4 plants. Using proteome profiling (2-D PAGE followed by MALDI-TOF/MS), we identified 29 protein spots that were increased in the SEN1::AtGA2ox4 plants, but were decreased to wild-type levels by GA3 treatment. The majority were found to be involved in photosynthesis and carbon/energy metabolism. Unlike the previous constitutive over-expression of GA2-oxidases, which frequently led to floral deformity and/or loss of fertility, the SEN1::AtGA2ox4 plants retained normal floral morphology and seed production. Accordingly, the expressions of FT and CO genes remained unchanged in the SEN1::AtGA2ox4 plants. Taken together, our results suggest that the dominant dwarf trait carried by SEN1::AtGA2ox4 plants can be used as an efficient dwarfing tool in plant biotechnological applications.
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endophytic fungi produce gibberellins and indoleacetic acid and promotes host plant growth during stress
Molecules, 2012Co-Authors: Muhammad Waqas, Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Yoonha Kim, Muhammad Kamran, In-jung LeeAbstract:We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs) and indoleacetic acid (IAA) and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7) in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.
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endophytic fungal association via gibberellins and indole acetic acid can improve plant growth under abiotic stress an example of paecilomyces formosus lhl10
BMC Microbiology, 2012Co-Authors: Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Yoonha Kim, Heeyoung Jung, Joonghwan Lee, In-jung LeeAbstract:Endophytic fungi are little known for exogenous secretion of phytohormones and mitigation of salinity stress, which is a major limiting factor for agriculture production worldwide. Current study was designed to isolate phytohormone producing endophytic fungus from the roots of cucumber plant and identify its role in plant growth and stress tolerance under saline conditions. We isolated nine endophytic fungi from the roots of cucumber plant and screened their culture filtrates (CF) on gibberellins (GAs) deficient mutant rice cultivar Waito-C and normal GAs biosynthesis rice cultivar Dongjin-byeo. The CF of a fungal isolate CSH-6H significantly increased the growth of Waito-C and Dongjin-byeo seedlings as compared to control. Analysis of the CF showed presence of GAs (GA1, GA3, GA4, GA8, GA9, GA12, GA20 and GA24) and indole acetic acid. The endophyte CSH-6H was identified as a strain of Paecilomyces formosus LHL10 on the basis of phylogenetic analysis of ITS sequence similarity. Under salinity stress, P. formosus inoculation significantly enhanced cucumber shoot length and allied growth characteristics as compared to non-inoculated control plants. The hypha of P. formosus was also observed in the cortical and pericycle regions of the host-plant roots and was successfully re-isolated using PCR techniques. P. formosus association counteracted the adverse effects of salinity by accumulating proline and antioxidants and maintaining plant water potential. Thus the electrolytic leakage and membrane damage to the cucumber plants was reduced in the association of endophyte. Reduced content of stress responsive abscisic acid suggest lesser stress convened to endophyte-associated plants. On contrary, elevated endogenous GAs (GA3, GA4, GA12 and GA20) contents in endophyte-associated cucumber plants evidenced salinity stress modulation. The results reveal that mutualistic interactions of phytohormones secreting endophytic fungi can ameliorate host plant growth and alleviate adverse effects of salt stress. Such fungal strain could be used for further field trials to improve agricultural productivity under saline conditions.
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exophiala sp lhl08 reprograms cucumis sativus to higher growth under abiotic stresses
Physiologia Plantarum, 2011Co-Authors: Muhammad Hamayun, Nadeem Ahmad, Abdul Latif Khan, Muhammad Waqas, Sang-mo KangAbstract:Endophytic fungi are potential sources of secondary metabolites; however, they are little known for phytohormones secretion and amelioration of plant growth under abiotic stresses. We isolated a novel endophyte from the roots of Cucumis sativus and identified it as a strain of Exophiala sp. by sequencing internal transcribed spacer/large subunit rDNA and phylogenetic analysis. Prior to identification, culture filtrate (CF) of Exophiala sp. has shown significant growth promotion of Waito-C [a gibberellins (GAs)-deficient mutant cultivar] and Dongjin-byeo (normal GAs biosynthesis cultivar) rice seedlings. CF analysis of Exophiala sp. showed the presence of physiologically active GAs (GA1, GA3, GA4 and GA7) and inactive GAs (GA5, GA8, GA9, GA12 and GA20). Exophiala sp. had higher GAs in its CF than wild-type strain of Gibberella fujikuroi except GA3. Influence of Exophiala sp. was assessed on cucumber plant's growth and endogenous abscisic acid (ABA), salicylic acid (SA) and bioactive GAs under salinity and drought stresses. Exophiala sp.-treated plants have shown significantly higher growth and rescued the host plants from stress promulgated water deficit, osmotic and cellular damage. The altered levels of stress-responsive ABA showed low level of stress confined to endophyte-applied plants than control. Elevated levels of SA and bioactive GAs (GA3 and GA4) in endophyte-associated plants suggest stress-modulating response toward salinity and drought. In conclusion, symbiotic relations between Exophiala and cucumber have reprogrammed the host plant growth under abiotic stresses, thus indicating a possible threshold role of endophytic fungi in stress alleviation. This study could be extended for improving agricultural productivity under extreme environmental conditions.
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exogenous application of plant growth regulators increased the total flavonoid content in taraxacum officinale wigg
African Journal of Biotechnology, 2009Co-Authors: Yoonha Kim, Sang-mo Kang, Muhammad Hamayun, Abdul Latif Khan, Hyun Hee Han, In-jung LeeAbstract:The effects of plant growth regulators (PGRs) were studied on growth, total flavonoid, gibberellins (GA) and salicylic acid (SA) contents of Taraxacum officinale (dandelion), a widely used medicinal plant in Korea. All the four PGRs used; gibberellic acid (GA3), kinetin (Kn), salicylic acid (SA) and ethephon (2- chloroethylphosphonic acid) were applied at the rates of 0.5 and 1.0 mM. GA3 markedly enhanced fresh shoot weight, while 0.5 mM of kinetin application significantly enhanced dry root mass as compared to control. SA enhanced both shoot and root attributes, while ethephon decreased plant growth. Endogenous bioactive GA1 and GA4 content and SA content enhanced with the application of GA3, SA and kinetin, but declined with ethephon. The flavonoid content of dandelion significantly increased with SA treatment, but was not altered with the application of other PGRs. The current study demonstrated the favorable effect of GA3, kinetin and SA on growth, bioactive GAs, SA and flavonoid contents of dandelion. These investigations offered interesting information as PGRs were never tested for plant growth and development of dandelion. It also reports the presence of both early C-13 hydroxylation and non C-13 hydroxylation pathways of GA biosynthesis in dandelion for the first time.
