• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.189-189
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• 2017

Salinity is one of the major abiotic stresses that severely affect crop production throughout the world; especially rice plant which is generally categorized as a typical glycophyte as it cannot grow in the presence of salinity. Phenotypic resistance of salinity is expressed as the ability to survive and grow in a salinity condition. Salinity resistance has, at least implicitly, been treated as a single trait. Physiological studies of rice suggest that a range of characteristics (such as low shoot sodium concentration, compartmentation of salt in older rather than younger leaves, high potassium concentration, high $K^+/Na^+$ ratio, high biomass and plant vigour) would increase the ability of the plant to cope with salinity. Criteria for evaluating and screening salinity tolerance in crop plants vary depending on the level and duration of salt stress and the plant developmental stage. Plant growth responses to salinity vary with plant life cycle; critical stages sensitive to salinity are germination, seedling establishment and flowering. We have established a standard protocol to evaluate large rice germplasms for overall performance based on specific physiological traits for salt tolerance at seedling stage. This protocol will help in identifying germplasms which can perform better in the presence of different salinity treatments based on single trait and also combination of different physiological traits. The salt tolerant germplasm can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

• BMB Reports
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• v.38 no.4
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• pp.420-431
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• 2005

The differentially virulent race T1 of common bunt (Tilletia tritici) was used to inoculate the wheat lines Neepawa (compatible) and its sib BW553 (incompatible) that are nearly isogenic for the Bt-10 resistance gene. Inoculated crown tissues were used to construct a suppression subtractive hybridization (SSH) cDNA library. Of the 1920 clones arrayed from the SSH cDNA library, approximately 10% were differentially regulated. A total of 168 differentially up-regulated and 25 down-regulated genes were identified and sequenced; 71% sequences had significant homology to genes of known function, of which 59% appeared to have roles in cellular metabolism and development, 24% in abiotic/biotic stress responses, 3% involved in transcription and signal transduction responses. Two putative resistance genes and a transcription factor were identified among the up regulated sequences. The expression of several candidate genes including a lipase, two non-specific lipid transfer proteins (ns-LTPs), and several wheat pathogenesis-related (PR)-proteins, was evaluated following 4 to 32 days post-inoculation in compatible and incompatible interactions. Results confirmed the higher overall expression of these genes in resistant BW553 compared to susceptible Neepawa, and the differential up-regulation of wheat lipase, chitinase and PR-1 proteins in the expression of the incompatible interaction.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.30-36
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• 2016

Brassinosteroids (BRs) are essential plant steroid hormones required for cell elongation, plant growth, development and abiotic and biotic stress tolerance. BRs are recognized by BRI1 receptor kinase that is localized in the plasma membrane, and the BRI1 protein will eventually autophosphorylate in the intracellular domain and transphosphorylate BAK1, which is a co-receptor in Arabidopsis thaliana. However, little is known of the role OsBRI1 receptor kinase plays in Oryza sativa, monocotyledonous plants, compared to that in Arabidopsis thaliana, dicotyledonous plants. As such, we have studied OsBRI1 receptor kinase in vitro and in vivo with recombinant protein and transgenic plants, whose phenotypes were also investigated. A OsBRI1 cytoplasmic domain (CD) recombinant protein was induced in BL21 (DE3) E.coli cells with IPTG, and purified to obtain OsBRI1 recombinant protein. Based on Western blot analysis with phospho-specific pTyr and pThr antibodies, OsBRI1 recombinant protein and OsBRI1-Flag protein were phosphorylated on Threonine residue(s), however, not on Tyrosine residue(s), both in vitro and in vivo. This is particularly intriguing as AtBRI1 protein was phosphorylated on both Ser/Thr and Tyr residues. Also, the OsBRI1 full-length gene was expressed in, and rescued, bri1-5 mutants, such as is seen in normal wild-type plants where AtBRI1-Flag rescues bri1-5 mutant plants. Root growth in seedlings decreased in Ws2, AtBRI1, and 3 independent OsBRI1 transgenic seedlings and had an almost complete lack of response to brassinolide in the bri1-5 mutant. In conclusion, OsBRI1, an orthologous gene of AtBRI1, can mediate normal BR signaling for plant growth and development in Arabidopsis thaliana.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.232-238
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• 2014

We have developed a non-destructive, touch-free method for estimating leaf areas with a structured-light three-dimensional (3D) scanner. When the surfaces of soybean leaves were analyzed with both the 3D scanner and a leaf area meter, the results were linearly related ($R^2=0.90$). The strong correlation ($R^2=0.98$) was calculated between shoot fresh weights and leaf areas when the scanner was employed during growth stages V1 to V4. We also found that leaf areas measured by the scanner could be used to detect changes in growth responses to abiotic stress. Whereas under control conditions the areas increased over time, salt and drought treatments were associated with reductions in those values after 14 d and 12 d, respectively. Based on our findings, we propose that a structured-light 3D scanner can be used to obtain reliable estimates of leaf area and plant biomass.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.249-255
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• 2009

The oxidation of glycolate to glyoxylate, a key step in plant photorespiration, is carried out by the peroxisomal flavoprotein glycolate oxidase (EC 1.1.3.15). To investigate the altered gene expression and the role of GOX in ginseng plant defense system, a cDNA clone containing a GOX gene designated as PgGOX was isolated and sequenced from Panax ginseng. The cDNA was 692 nucleotides long and have an open reading frame of 552 bp with a deduced amino acid sequence of 183 residues. A GenBank BlastX search revealed that the deduced amino acid of PgGOX shares a high degree homology with the Glycine max (95% identity). In the present study we analyzed the expression of PgGOX under various environmental stresses at different times using real time-PCR. The results showed that the expressions of PgGOX increased after various treatments involving salt, light, cold, ABA, SA, and copper treatment.

• Molecules and Cells
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• v.19 no.1
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• pp.67-73
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• 2005

Isoflavones are synthesized by isoflavone synthases via the phenylpropanoid pathway in legumes. We have cloned two isoflavone synthase genes, IFS1 and IFS2, from a total of 18 soybean cultivars. The amino acid residues of the proteins that differed between cultivars were dispersed over the entire coding region. However, amino acid sequence variation did not occur in conserved domains such as the ERR triad region, except that one conserved amino acid was changed in the IFS2 protein of the GS12 cultivar ($R_{374}G$) and the IFS1 proteins of the 99M06 and Soja99s65 cultivars ($A_{109}T$, $F_{105}I$). In three cultivars (99M06, 99M116, and Simheukpi), most of amino acid changes were such that the difference between the amino acid sequences of IFS1 and IFS2 was reduced. The expression profiles of three enzymes that convert naringenin to the isoflavone, genistein, chalcone isomerase (CHI), isoflavone synthase (IFS) and flavanone 3-hydroxylase (F3H) were examined. In general, IFS mRNA was more abundant in etiolated seedlings than mature plants whereas the levels of CHI and F3H mRNAs were similar in the two stages. During seed development, IFS was expressed a little later than CHI and F3H but expression of these three genes was barely detectable, if at all, during later seed hardening. In addition, we found that the levels of CHI, F3H, and IFS mRNAs were under circadian control. We also showed that IFS was induced by wounding and by application of methyl jasmonate to etiolated soybean seedlings.

• Journal of Ginseng Research
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• v.37 no.2
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• pp.227-247
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• 2013

MicroRNAs (miRNAs) are a class of recently discovered non-coding small RNA molecules, on average approximately 21 nucleotides in length, which underlie numerous important biological roles in gene regulation in various organisms. The miRNA database (release 18) has 18,226 miRNAs, which have been deposited from different species. Although miRNAs have been identified and validated in many plant species, no studies have been reported on discovering miRNAs in Panax ginseng Meyer, which is a traditionally known medicinal plant in oriental medicine, also known as Korean ginseng. It has triterpene ginseng saponins called ginsenosides, which are responsible for its various pharmacological activities. Predicting conserved miRNAs by homology-based analysis with available expressed sequence tag (EST) sequences can be powerful, if the species lacks whole genome sequence information. In this study by using the EST based computational approach, 69 conserved miRNAs belonging to 44 miRNA families were identified in Korean ginseng. The digital gene expression patterns of predicted conserved miRNAs were analyzed by deep sequencing using small RNA sequences of flower buds, leaves, and lateral roots. We have found that many of the identified miRNAs showed tissue specific expressions. Using the insilico method, 346 potential targets were identified for the predicted 69 conserved miRNAs by searching the ginseng EST database, and the predicted targets were mainly involved in secondary metabolic processes, responses to biotic and abiotic stress, and transcription regulator activities, as well as a variety of other metabolic processes.

• Journal of Ginseng Research
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• v.39 no.4
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• pp.406-413
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• 2015

Background: Pathogenesis-related 10 (PR-10) proteins are small, cytosolic proteins with a similar three-dimensional structure. Crystal structures for several PR-10 homologs have similar overall folding patterns, with an unusually large internal cavity that is a binding site for biologically important molecules. Although structural information on PR-10 proteins is substantial, understanding of their biological function remains limited. Here, we showed that one of the PgPR-10 homologs, PgPR-10.3, shares binding properties with flavonoids, kinetin, emodin, deoxycholic acid, and ginsenoside Re (1 of the steroid glycosides). Methods: Gene expression patterns of PgPR-10.3 were analyzed by quantitative real-time PCR. The three-dimensional structure of PgPR-10 proteins was visualized by homology modeling, and docking to retrieve biologically active molecules was performed using AutoDock4 program. Results: Transcript levels of PgPR-10.3 expressed in leaves, stems, and roots of 3-wk-old ginseng plantlets were on average 86-fold lower than those of PgPR-10.2. In mature 2-yr-old ginseng plants, the mRNA of PgPR-10.3 is restricted to leaves. Ginsenoside Re production is especially prominent in leaves of Panax ginseng Meyer, and the binding property of PgPR-10.3 with ginsenoside Re suggests that this protein has an important role in the control of secondary metabolism. Conclusion: Although ginseng PR-10.3 gene is expressed in all organs of 3-wk-old plantlets, its expression is restricted to leaves in mature 2-yr-old ginseng plants. The putative binding property of PgPR-10.3 with Re is intriguing. Further verification of binding affinity with other biologically important molecules in the large hydrophobic cavity of PgPR-10.3 may provide an insight into the biological features of PR-10 proteins.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.419-427
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• 2017

Background: Glycosylation of natural compounds increases the diversity of secondary metabolites. Glycosylation steps are implicated not only in plant growth and development, but also in plant defense responses. Although the activities of uridine-dependent glycosyltransferases (UGTs) have long been recognized, and genes encoding them in several higher plants have been identified, the specific functions of UGTs in planta remain largely unknown. Methods: Spatial and temporal patterns of gene expression were analyzed by quantitative reverse transcription (qRT)-polymerase chain reaction (PCR) and GUS histochemical assay. In planta transformation in heterologous Arabidopsis was generated by floral dipping using Agrobacterium tumefaciens (C58C1). Protein localization was analyzed by confocal microscopy via fluorescent protein tagging. Results: PgUGT72AL1 was highly expressed in the rhizome, upper root, and youngest leaf compared with the other organs. GUS staining of the promoter: GUS fusion revealed high expression in different organs, including axillary leaf branch. Overexpression of PgUGT72AL1 resulted in a fused organ in the axillary leaf branch. Conclusion: PgUGT72AL1, which is phylogenetically close to PgUGT71A27, is involved in the production of ginsenoside compound K. Considering that compound K is not reported in raw ginseng material, further characterization of this gene may shed light on the biological function of ginsenosides in ginseng plant growth and development. The organ fusion phenotype could be caused by the defective growth of cells in the boundary region, commonly regulated by phytohormones such as auxins or brassinosteroids, and requires further analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.148-153
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• 2004

The Hessian fly, Mayetiola destructor (Say), is known to be one of the major insect herbivores of wheat worldwide. In order to provide molecular events on interactions of the NIL with H21 and larvae of Hessian fly biotype L, the TaCR1 gene, Triticum aestivum cytokinin repressed 1, was isolated through the suppression subtractive hybridization, which was constructed using stems of the NIL with H21 at 6 days after infestation as tester and stems of the recurrent parent Coker797 without H21 at 6 days after infestation as driver. Transcript levels of TaCR1 mRNA in the NIL with H21 were highest at 6 days after infestation but in the Coker797 without H21 until 8 days were similar with those of non-infested plants. Expression of the TaCR1 gene was decreased at early time and then recovered after wounding or $H_2O$$_2$ treatment as well as 6-BAP treatment. Transcripts levels of the TaCR1 gene was changed after MeJA, SA, ethephone, or ABA treatment. In drought treatment, the TaCRl gene were increased at early stage of stress and then decreased at late stage. Expression of the TaCRl gene was continued to decrease through 24 h in the cold treatment. Although the TaCRl gene is increased through infestation in NIL with H21, further study was required to elucidate a role on resistance against larvae of Hessian fly. However, the TaCR1 gene could be used as marker gene on response of plants against abiotic stresses as well as application of plants with several hormones.