• Plant Biotechnology Reports
• /
• v.4 no.2
• /
• pp.173-178
• /
• 2010

An efficient protocol for shoot regeneration was developed for sesame (Sesamum indicum L.) internodes using the transverse thin cell layer (tTCL) culture method. The frequency of shoot regeneration and the number of adventitious buds produced from regenerated shoots depend significantly on explant age, thickness of the tTCL sections, and the phytohormones supplemented to the culture medium. A combination of 6-benzyladenine (2.0 $mg\;l^{-1}$) and a-naphthaleneacetic acid (0.5 $mg\;l^{-1}$) was found to be the best phytohormone combination for shoot bud induction, with the maximum number of shoots obtained when the tTCL sections were 0.5-1.0 mm thick and derived from 4- to 6-week-old seedlings of sesame. Well-developed shoots were rooted on MS medium without phytohormones, and 80% of the regenerated plantlets were successfully established in soil.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.202-202
• /
• 2017

Global climate change resulted in unwarranted change in global temperature and caused heat and cold stress, which are consider major threat to agriculture productivity around the world. The use of plant growth-promoting microbes is an eco-friendly strategy to counteract such stresses and confer tolerance to the plants. In current study, previously isolated endophytic fungi Preussia sp. BSL-10 has been found to produce phytohormones such as IAA and GA and as such, endophyte Preussia sp. BSL-10 found to induced tolerance against heat and cold stress. The results showed that under both heat and cold stress the plant growth parameter such as shoot, root length, shoot fresh weight and root fresh weight is higher in Preussia sp. BSL-10 treated plants as compare to free Preussia sp. BSL-10 control plants. In addition, the stress-sensitive endogenous ABA levels were significantly increased in Preussia sp. BSL-10 host plant. The current result suggest that the phytohormone-producing endophyte Preussia sp. BSL-10 can increase plant resistance toheat and cold stress, in turn improving agricultural productivity.

• Journal of Plant Biotechnology
• /
• v.7 no.3
• /
• pp.149-153
• /
• 2005

In the present study, in vitro multiple shoot induction was achieved from cotyledonary node and stem nodal explants of cv. NARI-6 of safflower (Carthamus tinctorius L.). Among various growth regulators tested, MS salts and B5 vitamins supplemented with BA (6-Benzy-laminopurine) $17.76\;{\mu}M$ and KN (Kinetin) $6.96\;{\mu}M$ phytohormonal combination was found to be the most effective in initiating numerous shoot buds after 30 days of culture than BA ($4.44-44.39\;{\mu}M$) or KN ($2.32-46.40\;{\mu}M$) alone in the medium. In addition, 0.8% (w/v) agar (Hi-media) and 3.0% sucrose (w/v) was the optimum level for the formation of adventitious shoots. Further results showed the maximum shoot elongation occurred on MS medium with BA ($8.88\;{\mu}M$) and $GA_3$($11.56\;{\mu}M$) combinations. Efficient rooting occurred on quarter strength MS medium with NAA $10.74\;{\mu}M$. The regenerated plantlets were acclimatized and successfully transferred to the field.

• Korean Journal of Microbiology
• /
• v.14 no.2
• /
• pp.49-49
• /
• 1976

Enzyme activities, such as glucoamylase dextrinogenic amylase, cellulase, acid protase and neutral protease, of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their enzyme activities are surveyed from taxonomical, ecological and physiological viewpoint. Effect of carbon sources and phytohormones on the amylalse production of Rhizopus are also measured. Among the 735 strains of Phizopus isolated, strain number 587 exhibiting most prominent dextrinogenic amylase and netral protease activity is selected as the best strain, and the strain number 673, 108, 329, 165 and 728 are seleted for their predominant cellulase, acid protease, glucoamylase, dextrinogenic amylase and neutral protease activities, respectively. R.acidus and R.nigricans which exhibited relatively higher callulalse activity, showed lower activities for both amylase. R.tritici exhibited higher protease activity. The relations between activities and various substrates of wild strains are not outstnading difference, although the strains isolated from inland region exhibited more or less higher amylase and cellulase activities, than those of coast region, generally. Lactose and dextrin are most effective carbon sources for glucoamylase and dextrinogenic amylase production of the Rhizopus niveus, respectively. Although all phytohormones tested are effective for production of amylase by the Rhizopus strains, except nicotinamide for glucoamylase production, biotin and ascorbate are most effective for dextrinogenic amylase and glucoamylase production, respectively.

• Korean Journal of Microbiology
• /
• v.14 no.2
• /
• pp.47-56
• /
• 1976

Enzyme activities, such as glucoamylase dextrinogenic amylase, cellulase, acid protase and neutral protease, of Rhizopus isolated from various substrates collected throughout South Korea are measured, and their enzyme activities are surveyed from taxonomical, ecological and physiological viewpoint. Effect of carbon sources and phytohormones on the amylalse production of Rhizopus are also measured. Among the 735 strains of Phizopus isolated, strain number 587 exhibiting most prominent dextrinogenic amylase and netral protease activity is selected as the best strain, and the strain number 673, 108, 329, 165 and 728 are seleted for their predominant cellulase, acid protease, glucoamylase, dextrinogenic amylase and neutral protease activities, respectively. R.acidus and R.nigricans which exhibited relatively higher callulalse activity, showed lower activities for both amylase. R.tritici exhibited higher protease activity. The relations between activities and various substrates of wild strains are not outstnading difference, although the strains isolated from inland region exhibited more or less higher amylase and cellulase activities, than those of coast region, generally. Lactose and dextrin are most effective carbon sources for glucoamylase and dextrinogenic amylase production of the Rhizopus niveus, respectively. Although all phytohormones tested are effective for production of amylase by the Rhizopus strains, except nicotinamide for glucoamylase production, biotin and ascorbate are most effective for dextrinogenic amylase and glucoamylase production, respectively.

• Journal of Microbiology
• /
• v.41 no.4
• /
• pp.271-276
• /
• 2003

The inoculation of some microorganisms into a microcosm containing soil from a barren lakeside area at Lake Paro in Kangwon-do enhanced plant growth significantly. The direct and viable counts of soil bacteria and soil microbial activities measured by electron transport system assay and fluorescein diacetate hydrolysis assay were higher in inoculated soil. The plant growth promoting effect of this inoculation may be caused by phytohormone production and the solubilization of insoluble phosphates by the inoculated bacteria. Three inoculated strains of Pseudomonas fluorescens produced several plant growth promoting phytohormones, including indole-3-acetic acid (auxin), which was confirmed by thin layer chromatography and GC/MS. P. fluorescens strain B16 and M45 produced 502.4 and 206.1 mg/l of soluble phosphate from Ca3(PO4)2 and hydroxyapatite, respectively. Bacillus megaterium showed similar solubilization rates of insoluble phosphates to those of Pseudomonas spp. We believe that this plant growth promoting capability may be used for the rapid revegetation of barren or disturbed land.

• Microbiology and Biotechnology Letters
• /
• v.47 no.1
• /
• pp.1-10
• /
• 2019

Saline soils comprise more than half a billion hectares worldwide. Thus, they warrant attention for their efficient, economical, and environmentally acceptable management. Halophytes are being progressively utilized for human benefits. The halophyte microbiome contributes significantly to plant performance and can provide information regarding complex ecological processes involved in the osmoregulation of halophytes. Microbial communities associated with the rhizosphere, phyllosphere, and endosphere of halophytes play an important role in plant health and productivity. Members of the plant microbiome belonging to domains Archaea, Bacteria, and kingdom Fungi are involved in the osmoregulation of halophytes. Halophilic microorganisms principally use compatible solutes, such as glycine, betaine, proline, trehalose, ectoine, and glutamic acid, to survive under salinity stress conditions. Plant growth-promoting rhizobacteria (PGPR) enhance plant growth and help to elucidate tolerance to salinity. Detailed studies of the metabolic pathways of plants have shown that plant growth-promoting rhizobacteria contribute to plant tolerance by affecting the signaling network of plants. Phytohormones (indole-3-acetic acid and cytokinin), 1-aminocyclopropane-1-carboxylic acid deaminase biosynthesis, exopolysaccharides, halocins, and volatile organic compounds function as signaling molecules for plants to elicit salinity stress. This review focuses on the functions of plant microbiome and on understanding how the microorganisms affect halophyte health and growth.

• Journal of Crop Science and Biotechnology
• /
• v.10 no.1
• /
• pp.50-56
• /
• 2007

Barley S-adenosylmethionine synthetase1 gene, which was differentially expressed in seed development of extra early barley, was regulated by the phytohormones and abiotic stresses. In order to identify the regulation regions which were involved in transcriptional control of the phytohormones and abiotic stresses, we isolated 1459 bp fragment of HvSAMS1 gene promoter using genome walking strategy and deletion series were constructed. Deleted upstream fragments(-1459, -1223, -999, -766, -545, -301 bp) were fused to the GUS reporter gene and evaluated via Agrobacterium-mediated transient expression assay. Increased GUS activity of HvSMAS1 promoter -301/GUS construct under each of NaCl, $GA_3$, ABA and ethylene application was found. However, GUS activity was negligible in the leaves transformed with the HvSMAS1 promoter(-1459, -1223, -999, -766 and -545)/GUS constructs. No significant induction of GUS activity was observed for the ethionine and spermidine treatments. In order to locate promoter sequence of the HvSAMS1 gene that was critical for the activation of gene expression, deletion and addition promoter derivatives(+, includes 43 bp of 5' ORF) of the HvSAMS1 gene fused to the GUS reporter gene were applied. The tobacco leaves which harbored the additional HvSAMS1 promoter(-1459+, -1459 to -546, -545+ and -301+)/GUS construct did not significantly induce GUS activity as compared to the HvSAMS1 promoter(-1459, -545 and -301)/GUS constructs under each of NaCl, ABA and $GA_3$ treatment. However, the GUS activity was high in the tobacco leaves which harboring the -211 to -141 regions of the HvSAMS1 promoter. This result suggested that HvSAMS1 gene expression might be regulated by this region(from -211 to -141).

• The Plant Pathology Journal
• /
• v.26 no.4
• /
• pp.386-393
• /
• 2010

In order to study disease resistance mechanisms in rice against the rice blast fungus Magnaporthe grisea, we screened fungal elicitor-responsive genes from rice suspension-cultured cells treated with fungal elicitors employing differential hybridization (DH). By DH screening, 31 distinct rice clones were isolated and a majority of them were full-length cDNAs encoding pathogenesisrelated (PR) genes. Sixteen of the 31 genes were upregulated at 4, 8, and 12 h following fungal elicitor treatment. To elucidate the effect of signal molecules and biotic elicitors on the regulation of rice defense genes, we further characterized the transcriptional expression patterns of representative isolated PR genes; OsGlu1, OsGlu2, OsTLP, OsRLK, and OsPR-10, following treatment with fungal elicitor, phytohormones, cycloheximide, and inhibitors of protein phosphorylation. Jasmonic acid (JA) induced transcriptional expression of OsGlu1, OsTLP, and OsRLK, but not of OsGlu2 and OsPR-10 at any of the tested time points. Salicylic acid (SA) and abscisic acid weakly induced the expression of OsTLP and OsRLK. SA showed an antagonistic effect with fungal elicitor and JA. Cycloheximide suppressed all these genes upon elicitor treatment, except for OsGlu2. Staurosporine only induced the expression of OsRLK. Application of calyculin A strongly induced OsRLK expression, but suppressed the expression of OsGlu2. Our study yielded a number of PR genes that play a role in defense mechanisms against the rice blast fungus, as well as contribute towards the elucidation of crosstalk between phytohormones and other modifications during defense signaling.

• Journal of Plant Biology
• /
• v.32 no.4
• /
• pp.313-322
• /
• 1989

A system was established for induction of multi-shoots and plant regeneration from mesophyll protoplasts of alfalfa, Medicago sativa L. cv. Vernal. Different hormonal effects were tested at each step of protoplast culture, i.e. cell division in modified Kao's liquid medium (K566-7). calli formation on SH semi solid medium, and multi-shoot regeneration from calli on SHa and SHb solid media. Frequency of multi-shoots and plant regeneration was affected by various combinations of phytohormones in final step. The evaluation of multi-shoots induction systems via protoplast culture was discused.