Production and characterization of polyclonal antibody against Arabidopsis GIGANTEA, a circadian clock controlled flowering time regulator

Khaleda, Laila,Cha, Joon-Yung,Kim, Min Gab,Kim, Woe-Yeon Botanical Society of Korea 2017 Journal of plant biology Vol.60 No.6

<P>Arabidopsis GIGANTEA (GI) is encoded by a single gene and highly conserved among vascular plants and its mutants display pleiotropic phenotypes involved in diverse biological processes such as light signaling, circadian clock, and sucrose metabolism as well as abiotic stress responses. However, molecular mechanisms of GI are largely unknown due to the lack of useful antibody. To date, the epitope tags have been widely used to detect GI in plants, but it needs to generate the transgenic plants which take a few months. Here, we produced polyclonal alpha-GI antibody using truncated variants of GI having amino-terminal (1-858 aa) and carboxyl-terminal (920-1173) regions as antigens. Both recombinant His-GI(1-858) and His-GI(920-1173) proteins were individually and successfully expressed in E. coli and immunized into rabbit. Anti-serum was purified by antigenspecific affinity purification method using both recombinant His-GI(1-858) and His-GI(920-1173) proteins. Purified polyclonal alpha-GI antibody not only detected endogenous GI proteins in wild-type Arabidopsis plants, but also reenacted its diel oscillations. Furthermore, the antibody showed cross-reactivity with the GI orthologs in other plants such as Chinese cabbage, rape and tomato. Our polyclonal GI antibody could help to determine the molecular mechanisms of GI involved in largely unknown pleiotropic responses in plants.</P>

Synthesis and Antiinflammatory Activity of Novel Indazolones

KhaledA.M.Abouzid,H.S.El-Abhar 대한약학회 2003 Archives of Pharmacal Research Vol.26 No.1

In this study, a series of new N2 substituted 1,2-dihydro-3H-indazol-3-ones (3a-d) as well as their condensed pyrazolo, pyridazino derivatives such as pyridazino[1,2- a]indazole-6,9,11-triones (4a-h) and 3,9-dioxo-3 H,9H-pyrazolo[1,2- a]indazole (7) were synthesized. The antiinflammatory activity of some synthesized compounds was determined by carrageenan-induced rat paw edema technique using diclofenac as reference drug. The pharmacological data showed that most of the tested compounds exhibited a significant long lasting antiinflammatory activity, which in the case of compound 3b was superior to that of diclofenac.

Foliar application of humic acid or a mixture of catechol and vanillic acid enhanced growth and productivity of alfalfa

Khaleda, Laila,Kim, Min Gab,Jeon, Jong-Rok,Cha, Joon-Yung,Kim, Woe-Yeon The Korean Society of Grassland and Forage Science 2017 한국초지조사료학회지 Vol.37 No.3

Humic acid (HA) is known to consist of various kinds of polymeric organics, their detailed structures can vary depend on sample sources such as organic manure, composts, peat, and lignite brown coal, and largely exists in grassland soils. HA possesses diverse positive effects that not only increase plant growth but also improve soil fertility. Recently, we have manufactured a co-polymeric product of catechol and vanillic acid (CAVA) synthesized artificially, and found that CAVA as a HA mimic increases seed germination and salt tolerance in Arabidopsis. In this study, we examined whether HA or CAVA affects to seedling growth in alfalfa. Foliar application of HA or CAVA increased alfalfa seedling growth including aerial and in root parts. HA or CAVA dramatically enhanced size of leaf and root, whereas HA significantly displayed higher bioactivity than CAVA. Taken together, CAVA acts like as a HA mimic in alfalfa that could apply as an alternation supplement to enhance plant growth and productivity.

Humic Acid Confers HIGH-AFFINITY K⁺ TRANSPORTER 1-Mediated Salinity Stress Tolerance in Arabidopsis

Khaleda, Laila,Park, Hee Jin,Yun, Dae-Jin,Jeon, Jong-Rok,Kim, Min Gab,Cha, Joon-Yung,Kim, Woe-Yeon Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.12

Excessive salt disrupts intracellular ion homeostasis and inhibits plant growth, which poses a serious threat to global food security. Plants have adapted various strategies to survive in unfavorable saline soil conditions. Here, we show that humic acid (HA) is a good soil amendment that can be used to help overcome salinity stress because it markedly reduces the adverse effects of salinity on Arabidopsis thaliana seedlings. To identify the molecular mechanisms of HA-induced salt stress tolerance in Arabidopsis, we examined possible roles of a sodium influx transporter HIGH-AFFINITY $K^+$ TRANSPORTER 1 (HKT1). Salt-induced root growth inhibition in HKT1 overexpressor transgenic plants (HKT1-OX) was rescued by application of HA, but not in wild-type and other plants. Moreover, salt-induced degradation of HKT1 protein was blocked by HA treatment. In addition, the application of HA to HKT1-OX seedlings led to increased distribution of $Na^+$ in roots up to the elongation zone and caused the reabsorption of $Na^+$ by xylem and parenchyma cells. Both the influx of the secondary messenger calcium and its cytosolic release appear to function in the destabilization of HKT1 protein under salt stress. Taken together, these results suggest that HA could be applied to the field to enhance plant growth and salt stress tolerance via post-transcriptional control of the HKT1 transporter gene under saline conditions.

3-[(6-Arylamino)pyridazinylamino]benzoic acids: design, synthesis and in vitro evaluation of anticancer activity

KhaledA.M.Abouzid,Nadia A. Khalil,Eman M. Ahmed,Khaled Omar Mohamed 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.1

A series of novel substituted 3,6-disubstitutedpyridazines based on the structure of vatalanib (PTK787)were designed and synthesized. The cytotoxicity of thefinal compounds was tested in vitro on HT-29 colon cancercell line. Compounds 2a and 2b with 4-chlorophenylaminomoiety, exerted the highest cytotoxic activity with IC50values equal to 15.3 and 3.9 lM respectively. The mostpromising compound, 2b, was found to be about fivefoldmore active than vatalanib against HT-29 colon cancer cellline.

Humic Acid and Synthesized Humic Mimic Promote the Growth of Italian Ryegrass

Khaleda, Laila,Kim, Min Gab,Kim, Woe-Yeon,Jeon, Jong-Rok,Cha, Joon-Yung The Korean Society of Grassland and Forage Science 2017 한국초지조사료학회지 Vol.37 No.3

Humic acid (HA) is a complex organic matter found in the environments, especially in grassland soils with a high density. The bioactivity of HA to promote plant growth depends largely on its extraction sources. The quality-control of HA and the quality improvements via an artificial synthesis are thus challenging. We recently reported that a polymeric product from fungal laccase-mediated oxidation of catechol and vanillic acid (CAVA) displays a HA-like activity to enhance seed germination and salt stress tolerance in a model plant, Arabidopsis. Here, we examined whether HA or CAVA enhances the growth of Italian ryegrass seedling. Height and fresh weight of the plant with foliar application of HA or CAVA were bigger than those with only water. Interestingly, enhanced root developments were also observed in spite of the foliar treatments of HA or CAVA. Finally, we proved that HA or CAVA promotes the regrowth of Italian ryegrass after cutting. Collectively, CAVA acts as a HA mimic in Italian ryegrass cultivation, and both as a biostimulant enhanced the early growth and regrowth after cutting of Italian ryegrass, which could improve the productivity of forage crops.

Production and characterization of polyclonal antibody against Arabidopsis GIGANTEA, a circadian clock controlled flowering time regulator

Laila Khaleda,차준영,김민갑,김외연 한국식물학회 2017 Journal of Plant Biology Vol.60 No.6

Arabidopsis GIGANTEA (GI) is encoded by asingle gene and highly conserved among vascular plants andits mutants display pleiotropic phenotypes involved indiverse biological processes such as light signaling, circadianclock, and sucrose metabolism as well as abiotic stressresponses. However, molecular mechanisms of GI arelargely unknown due to the lack of useful antibody. To date,the epitope tags have been widely used to detect GI in plants,but it needs to generate the transgenic plants which take afew months. Here, we produced polyclonal α-GI antibodyusing truncated variants of GI having amino-terminal (1-858aa) and carboxyl-terminal (920-1173) regions as antigens. Both recombinant His-GI1-858 and His-GI920-1173 proteins wereindividually and successfully expressed in E. coli andimmunized into rabbit. Anti-serum was purified by antigenspecificaffinity purification method using both recombinantHis-GI1-858 and His-GI920-1173 proteins. Purified polyclonal α-GI antibody not only detected endogenous GI proteins inwild-type Arabidopsis plants, but also reenacted its dieloscillations. Furthermore, the antibody showed cross-reactivitywith the GI orthologs in other plants such as Chinesecabbage, rape and tomato. Our polyclonal GI antibody couldhelp to determine the molecular mechanisms of GI involvedin largely unknown pleiotropic responses in plants.

Humic Acid Confers HIGH-AFFINITY K+ TRANSPORTER 1-Mediated Salinity Stress Tolerance in Arabidopsis

Laila Khaleda,박희진,윤대진,전종록,김민갑,차준영,김외연 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.12

Excessive salt disrupts intracellular ion homeostasis and inhibits plant growth, which poses a serious threat to global food security. Plants have adapted various strategies to survive in unfavorable saline soil conditions. Here, we show that humic acid (HA) is a good soil amendment that can be used to help overcome salinity stress because it markedly reduces the adverse effects of salinity on Arabidopsis thaliana seedlings. To identify the molecular mechanisms of HA-induced salt stress tolerance in Arabidopsis, we examined possible roles of a sodium influx transporter HIGH-AFFINITY K+ TRANSPORTER 1 (HKT1). Salt-induced root growth inhibition in HKT1 overexpressor transgenic plants (HKT1-OX) was rescued by application of HA, but not in wild-type and other plants. Moreover, salt-induced degradation of HKT1 protein was blocked by HA treatment. In addition, the application of HA to HKT1-OX seedlings led to increased distribution of Na+ in roots up to the elongation zone and caused the reabsorption of Na+ by xylem and parenchyma cells. Both the influx of the secondary messenger calcium and its cytosolic release appear to func-tion in the destabilization of HKT1 protein under salt stress. Taken together, these results suggest that HA could be applied to the field to enhance plant growth and salt stress tolerance via post-transcriptional control of the HKT1 transporter gene under saline conditions.

Overexpression of chloroplast-localized NADPH-dependent thioredoxin reductase C (NTRC) enhances tolerance to photo-oxidative and drought stresses in Arabidopsis thaliana

김미리,Laila Khaleda,정인정,김주연,이상열,차준영,김외연 한국식물학회 2017 Journal of Plant Biology Vol.60 No.2

Chloroplast is a major organelle that conducts photosynthesis to produce ATP and NADPH via conversion of water to oxygen in plant. While the photosynthesis occurs, molecular oxygen easily changes to reactive oxygen species (ROS) consisting of toxic oxygen radicals resulting in oxidative stress. NADPH-dependent thioredoxin reductases (NTRs) play a pivotal role to regulate the redox state of the thioredoxin system providing reducing power to peroxidase. Here, we identify whether chloroplast NTRC confers stress tolerance through maintenance of ROS in Arabidopsis. NTRC transcripts were two-fold induced at 1 h treatment exposed to a photooxidative agent, methyl viologen (MV). The enhanced NTRC transcripts conferred oxidative stress tolerance displaying that NTRC overexpressing plants (NTRCOX) were tolerant compared to Col-0 and knock-out (ntrc-ko) plants on MVcontaining media. MV-mediated ROS induction was not detected in NTRCOX whereas that was highly accumulated in Col-0 and ntrc-ko. We further examined that NTRCOX showed extreme drought tolerance with lower water loss compared to Col-0 and ntrc-ko. Drought-responsive genes such as RD29A and DREB2A were enhanced in NTRCOX by drought compared to Col-0 and ntrc-ko. The results suggest that NTRC overexpression contributes to maintaining ROS homeostasis under stress conditions and confers the tolerance to photo-oxidative and drought stresses.

Color Fastness and Tensile Properties of Cotton Fabric Dyed with Extract from Albizia Procera Sawdust

Shahin Sultana,Khaleda Akter,Md. Khabir Uddin Sarker,Riyadh Hossen Bhuiyan,Mohammad Majedul Haque,Md. Rafiqul Islam 한국섬유공학회 2022 Fibers and polymers Vol.23 No.10

Natural dye was extracted from Albizia procera sawdust by an aqueous extraction process. The extracted dye wasapplied to cotton fabric, and the dyeing techniques were evaluated. The metallic mordants FeSO4 and CuSO4 were used asdye fixing agents in this dyeing process. Different parameters, such as dye concentration, dyeing temperature, dyeing time,type of mordant, mordant concentration, and dyeing method, were evaluated. It was observed that the dye exhaustion oncotton fabric significantly increased with FeSO4 mordant over that with CuSO4. The shades of the dyed fabric were found tobe dark olive when the FeSO4 mordant was used and brown when the CuSO4 mordant was used. Pre-, meta-, and postmordantingdyeing methods were used to dye the fabric, but the meta-mordanting method was the most suitable for dyeingfabric with sawdust extract. Fourier transform infrared (FTIR) spectroscopy was performed on the extracted dyes and thedyed cotton fabric. The color fastness and tensile properties of all the dyed fabrics were evaluated and compared. The fabrictreated with FeSO4 as a mordant showed better color fastness and color strength (K/S) than the fabric treated with CuSO4mordant. However, the fabric treated with CuSO4 showed better tensile properties than the FeSO4 treated fabric and theundyed fabric.