메뉴 건너뛰기




Volumn 167, Issue 4, 2004, Pages 913-923

Sugar-induced tolerance to atrazine in Arabidopsis seedlings: Interacting effects of atrazine and soluble sugars on psbA mRNA and D1 protein levels

Author keywords

3 (3,4 dichlorophenyl) 1,1 dimethylurea; Arabidopsis; D1 protein; DCMU; fresh weight; FW; Herbicide; hexokinase; HXK; MS; Murashige and Skoog; photosystem II; Photosystem II; PSII; sis; Soluble carbohydrates; sugar insensitive; Tolerance; Wassilewskija; Ws

Indexed keywords

CHLOROPHYLL; CROPS; PLANTS (BOTANY); RNA; SUGAR (SUCROSE);

EID: 3543140688     PISSN: 01689452     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.plantsci.2004.05.036     Document Type: Article
Times cited : (42)

References (49)
  • 1
    • 0028259110 scopus 로고
    • Protective effect of exogenous polyamines against atrazine in pea plants
    • Zheleva D, Tsonev T, Sergiev I, Karanov E. Protective effect of exogenous polyamines against atrazine in pea plants. J. Plant Growth Regul. 13:1994;203-211
    • (1994) J. Plant Growth Regul. , vol.13 , pp. 203-211
    • Zheleva, D.1    Tsonev, T.2    Sergiev, I.3    Karanov, E.4
  • 3
    • 0034759280 scopus 로고    scopus 로고
    • Estimation of environmental impact of some of the most often occurring pesticides in Slovenian surface and underground water
    • Gotvajn A.Z, Zagorc-Koncan J, Tisler T. Estimation of environmental impact of some of the most often occurring pesticides in Slovenian surface and underground water. Water Sci. Technol. 44:2001;87-90
    • (2001) Water Sci. Technol. , vol.44 , pp. 87-90
    • Gotvajn, A.Z.1    Zagorc-Koncan, J.2    Tisler, T.3
  • 4
    • 0000459393 scopus 로고
    • Resistance of common groundsel to simazine and atrazine
    • Ryan G.F. Resistance of common groundsel to simazine and atrazine. Weed Sci. 18:1970;614-616
    • (1970) Weed Sci. , vol.18 , pp. 614-616
    • Ryan, G.F.1
  • 5
    • 0001108790 scopus 로고    scopus 로고
    • Herbicide metabolism as a basis of selectivity
    • T. Roberts (Ed.), Wiley, Chichester
    • W.J. Owen, Herbicide metabolism as a basis of selectivity, in: T. Roberts (Ed.), Metabolism of Agrochemicals in Plants, Wiley, Chichester, 2000, pp. 211-258.
    • (2000) Metabolism of Agrochemicals in Plants , pp. 211-258
    • Owen, W.J.1
  • 6
    • 0033926294 scopus 로고    scopus 로고
    • Identification of two mechanisms of atrazine resistance in Setaria faberi and Setaria viridis biotypes
    • De Prado R, Lopez-Martinez N, Gonzalez-Guttierez J. Identification of two mechanisms of atrazine resistance in Setaria faberi and Setaria viridis biotypes. Pesticide Biochem. Physiol. 67:2000;114-124
    • (2000) Pesticide Biochem. Physiol. , vol.67 , pp. 114-124
    • De Prado, R.1    Lopez-Martinez, N.2    Gonzalez-Guttierez, J.3
  • 7
    • 0031785144 scopus 로고    scopus 로고
    • A biotype of common waterhemp (Amaranthus rudis) resistant to triazine and ALS herbicides
    • Foes M.J, Liu L, Tranel P.J, Wax L.M, Stoller E.W. A biotype of common waterhemp (Amaranthus rudis) resistant to triazine and ALS herbicides. Weed Sci. 46:1998;514-520
    • (1998) Weed Sci. , vol.46 , pp. 514-520
    • Foes, M.J.1    Liu, L.2    Tranel, P.J.3    Wax, L.M.4    Stoller, E.W.5
  • 8
    • 0032973160 scopus 로고    scopus 로고
    • A kochia (Kochia scoparia) biotype resistant to triazine and ALS-inhibiting herbicides
    • Foes M.J, Liu L, Vigue G, Stoller E.W, Wax L.M, Tranel P.J. A kochia (Kochia scoparia) biotype resistant to triazine and ALS-inhibiting herbicides. Weed Sci. 47:1999;20-27
    • (1999) Weed Sci. , vol.47 , pp. 20-27
    • Foes, M.J.1    Liu, L.2    Vigue, G.3    Stoller, E.W.4    Wax, L.M.5    Tranel, P.J.6
  • 9
    • 0002704362 scopus 로고
    • A heuristic glance at the past of Arabidopsis genetics
    • C. Koncz, N.-H. Chua, J. Schell (Eds.), World Scientific, Singapore
    • G.P. Rédei, A heuristic glance at the past of Arabidopsis genetics, in: C. Koncz, N.-H. Chua, J. Schell (Eds.), Methods in Arabidopsis Research, World Scientific, Singapore, 1992, pp. 1-15.
    • (1992) Methods in Arabidopsis Research , pp. 1-15
    • Rédei, G.P.1
  • 11
    • 0037117599 scopus 로고    scopus 로고
    • Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically-relevant dose
    • Hayes T.B, Collins A, Lee M, Mendoza M, Noriega N, Stuart A.A, Vonk A. Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically-relevant dose. Proc. Natl. Acad. Sci. USA. 99:2002;5476-5480
    • (2002) Proc. Natl. Acad. Sci. USA , vol.99 , pp. 5476-5480
    • Hayes, T.B.1    Collins, A.2    Lee, M.3    Mendoza, M.4    Noriega, N.5    Stuart, A.A.6    Vonk, A.7
  • 12
    • 0000444532 scopus 로고
    • Determinations of total carotenoids and chlorophylls a and b of leaf extracts in different solvents
    • Lichtenthaler H.K, Wellburn A.R. Determinations of total carotenoids and chlorophylls a and b of leaf extracts in different solvents. Biochem. Soc. Trans. 11:1983;591-592
    • (1983) Biochem. Soc. Trans. , vol.11 , pp. 591-592
    • Lichtenthaler, H.K.1    Wellburn, A.R.2
  • 13
    • 0032826423 scopus 로고    scopus 로고
    • Chlorophyll fluorescence as a selection tool for cold tolerance of photosynthesis in maize (Zea mays L.)
    • Fracheboud Y, Haldimann P, Leipner J, Stamp P. Chlorophyll fluorescence as a selection tool for cold tolerance of photosynthesis in maize (Zea mays L.). J. Exp. Bot. 50:1999;1533-1540
    • (1999) J. Exp. Bot. , vol.50 , pp. 1533-1540
    • Fracheboud, Y.1    Haldimann, P.2    Leipner, J.3    Stamp, P.4
  • 14
    • 0031905338 scopus 로고    scopus 로고
    • Expression of a dominant negative form of cpSRP54 inhibits chloroplast biogenesis in Arabidopsis
    • Pilgrim M.L, van Wijk K.J, Parry D.H, Sy D.A, Hoffman N.E. Expression of a dominant negative form of cpSRP54 inhibits chloroplast biogenesis in Arabidopsis. Plant J. 13:1998;177-186
    • (1998) Plant J. , vol.13 , pp. 177-186
    • Pilgrim, M.L.1    Van Wijk, K.J.2    Parry, D.H.3    Sy, D.A.4    Hoffman, N.E.5
  • 15
    • 0038797798 scopus 로고    scopus 로고
    • Rapid, noninvasive screening for perturbations of metabolism and plant growth using chlorophyll fluorescence imaging
    • Barbagallo R.P, Oxborough K, Pallett K.E, Baker N.R. Rapid, noninvasive screening for perturbations of metabolism and plant growth using chlorophyll fluorescence imaging. Plant Physiol. 132:2003;485-493
    • (2003) Plant Physiol. , vol.132 , pp. 485-493
    • Barbagallo, R.P.1    Oxborough, K.2    Pallett, K.E.3    Baker, N.R.4
  • 16
    • 0029167906 scopus 로고
    • Regulation of D1-protein degradation during photoinhibition of photosystem II in vivo: Phosphorylation of the D1 protein in various plant groups
    • Rintamaki E, Salo R, Lehtonen E, Aro E.M. Regulation of D1-protein degradation during photoinhibition of photosystem II in vivo: phosphorylation of the D1 protein in various plant groups. Planta. 195:1995;379-386
    • (1995) Planta , vol.195 , pp. 379-386
    • Rintamaki, E.1    Salo, R.2    Lehtonen, E.3    Aro, E.M.4
  • 18
    • 0036649629 scopus 로고    scopus 로고
    • Histidine residue 252 of the photosystem II D1 polypeptide is involved in a light-induced cross-linking of the polypeptide with the α subunit of cytochrome b-559: Study of a site-directed mutant of Synechocystis PCC 6803
    • Lupinkova L, Metz J.G, Diner B.A, Vass I, Komenda J. Histidine residue 252 of the photosystem II D1 polypeptide is involved in a light-induced cross-linking of the polypeptide with the α subunit of cytochrome b-559: study of a site-directed mutant of Synechocystis PCC 6803. Biochim. Biophys. Acta. 1554:2002;192-201
    • (2002) Biochim. Biophys. Acta , vol.1554 , pp. 192-201
    • Lupinkova, L.1    Metz, J.G.2    Diner, B.A.3    Vass, I.4    Komenda, J.5
  • 19
    • 0026043886 scopus 로고
    • Photoinduced degradation of the D1 polypeptide in isolated reaction centers of photosystem II: Evidence for an autoproteolytic process triggered by the oxidizing side of the photosystem
    • Shipton C.A, Barber J. Photoinduced degradation of the D1 polypeptide in isolated reaction centers of photosystem II: evidence for an autoproteolytic process triggered by the oxidizing side of the photosystem. Proc. Natl. Acad. Sci. USA. 88:1991;6691-6695
    • (1991) Proc. Natl. Acad. Sci. USA , vol.88 , pp. 6691-6695
    • Shipton, C.A.1    Barber, J.2
  • 20
    • 0032126963 scopus 로고    scopus 로고
    • Sucrose-specific signalling represses translation of the Arabidopsis ATB2 bZIP transcription factor gene
    • Rook F, Gerrits N, Kortstee A, van Kampen M, Borrias M, Weisbeek P, Smeekens S. Sucrose-specific signalling represses translation of the Arabidopsis ATB2 bZIP transcription factor gene. Plant J. 15:1998;253-263
    • (1998) Plant J. , vol.15 , pp. 253-263
    • Rook, F.1    Gerrits, N.2    Kortstee, A.3    Van Kampen, M.4    Borrias, M.5    Weisbeek, P.6    Smeekens, S.7
  • 21
    • 0034741252 scopus 로고    scopus 로고
    • The sugar-insensitive1 (sis1) mutant of Arabidopsis is allelic to ctr1
    • Gibson S.I, Laby R.J, Kim D. The sugar-insensitive1 (sis1) mutant of Arabidopsis is allelic to ctr1. Biochem. Biophys. Res. Commun. 280:2001;196-203
    • (2001) Biochem. Biophys. Res. Commun. , vol.280 , pp. 196-203
    • Gibson, S.I.1    Laby, R.J.2    Kim, D.3
  • 22
    • 0034817783 scopus 로고    scopus 로고
    • Effects of sugar on vegetative development and floral development in Arabidopsis
    • Ohto M, Onai K, Furukawa Y, Aoki E, Araki T, Nakamura K. Effects of sugar on vegetative development and floral development in Arabidopsis. Plant Physiol. 127:2001;252-261
    • (2001) Plant Physiol. , vol.127 , pp. 252-261
    • Ohto, M.1    Onai, K.2    Furukawa, Y.3    Aoki, E.4    Araki, T.5    Nakamura, K.6
  • 23
    • 0028152032 scopus 로고
    • Carbon catabolite repression regulates glyoxylate cycle gene expression in cucumber
    • Graham I.A, Denby K.J, Leaver C.J. Carbon catabolite repression regulates glyoxylate cycle gene expression in cucumber. Plant Cell. 6:1994;761-772
    • (1994) Plant Cell , vol.6 , pp. 761-772
    • Graham, I.A.1    Denby, K.J.2    Leaver, C.J.3
  • 24
    • 0000920872 scopus 로고    scopus 로고
    • Carbohydrate-modulated gene expression in plants
    • Koch K.E. Carbohydrate-modulated gene expression in plants. Annu. Rev. Plant Physiol. Mol. Biol. 47:1996;509-540
    • (1996) Annu. Rev. Plant Physiol. Mol. Biol. , vol.47 , pp. 509-540
    • Koch, K.E.1
  • 25
    • 0033999195 scopus 로고    scopus 로고
    • Abscisic acid inhibition of radicle emergence but not seedling growth is suppressed by sugars
    • Finkelstein R.R, Lynch T.J. Abscisic acid inhibition of radicle emergence but not seedling growth is suppressed by sugars. Plant Physiol. 122:2000;1179-1186
    • (2000) Plant Physiol. , vol.122 , pp. 1179-1186
    • Finkelstein, R.R.1    Lynch, T.J.2
  • 26
    • 1842376846 scopus 로고    scopus 로고
    • Hexokinase as a sugar sensor in higher plants
    • Jang J-C, León P, Zhou L, Sheen J. Hexokinase as a sugar sensor in higher plants. Plant Cell. 9:1997;5-19
    • (1997) Plant Cell , vol.9 , pp. 5-19
    • Jang, J.-C.1    León, P.2    Zhou, L.3    Sheen, J.4
  • 27
    • 0036276818 scopus 로고    scopus 로고
    • Sugar sensing and signaling in plants
    • F. Rolland, B. Moore, J. Sheen, Sugar sensing and signaling in plants, Plant Cell (supplement) (2002) S185-S205.
    • (2002) Plant Cell , Issue.SUPPL.
    • Rolland, F.1    Moore, B.2    Sheen, J.3
  • 28
    • 0027981649 scopus 로고
    • Multiple effects of glycerol on plant metabolism
    • Aubert S, Gout E, Bligny R, Douce R. Multiple effects of glycerol on plant metabolism. J. Biol. Chem. 269:1994;21420-21427
    • (1994) J. Biol. Chem. , vol.269 , pp. 21420-21427
    • Aubert, S.1    Gout, E.2    Bligny, R.3    Douce, R.4
  • 29
    • 0027933692 scopus 로고
    • The role of glucose in cellular defences against cytotoxicity of hydrogen peroxide in Chinese hamster ovary cells
    • Averill-Bates D.A, Przybytkowski E. The role of glucose in cellular defences against cytotoxicity of hydrogen peroxide in Chinese hamster ovary cells. Arch. Biochem. Biophys. 312:1994;52-58
    • (1994) Arch. Biochem. Biophys. , vol.312 , pp. 52-58
    • Averill-Bates, D.A.1    Przybytkowski, E.2
  • 30
    • 0033988932 scopus 로고    scopus 로고
    • Induction of a futile Embden-Meyerhof-Parnas pathway in Deinococcus radiodurans by Mn: Possible role of the pentose phosphate pathway in cell survival
    • Zhang Y.-M, Wong T.-Y, Chen L.-Y, Lin C.-S, Liu J.-K. Induction of a futile Embden-Meyerhof-Parnas pathway in Deinococcus radiodurans by Mn: possible role of the pentose phosphate pathway in cell survival. Appl. Environ. Microbiol. 66:2000;105-112
    • (2000) Appl. Environ. Microbiol. , vol.66 , pp. 105-112
    • Zhang, Y.-M.1    Wong, T.-Y.2    Chen, L.-Y.3    Lin, C.-S.4    Liu, J.-K.5
  • 31
    • 85053492389 scopus 로고
    • Ascorbic acid
    • R.G. Alscher, J.L. Hess, (Eds.), CRC Press, Boca Raton
    • C. Foyer, Ascorbic acid, in: R.G. Alscher, J.L. Hess, (Eds.), Antioxidants in Higher Plants, CRC Press, Boca Raton, 1993, pp. 31-58.
    • (1993) Antioxidants in Higher Plants , pp. 31-58
    • Foyer, C.1
  • 32
    • 0002705740 scopus 로고
    • Carotenoids
    • R.G. Alscher, J.L. Hess (Eds.), CRC Press, Boca Raton
    • K.E. Pallett, A.J. Young, Carotenoids, in: R.G. Alscher, J.L. Hess (Eds.), Antioxidants in Higher Plants, CRC Press, Boca Raton, 1993, pp. 91-110.
    • (1993) Antioxidants in Higher Plants , pp. 91-110
    • Pallett, K.E.1    Young, A.J.2
  • 33
    • 0002709867 scopus 로고    scopus 로고
    • Herbicide safeners and synergists
    • T. Roberts (Ed.), Wiley and Sons, Chichester
    • K.K. Hatzios, Herbicide safeners and synergists, in: T. Roberts (Ed.), Metabolism of Agrochemicals in Plants, Wiley and Sons, Chichester, 2000, pp. 259-294.
    • (2000) Metabolism of Agrochemicals in Plants , pp. 259-294
    • Hatzios, K.K.1
  • 34
    • 0042531959 scopus 로고    scopus 로고
    • A flux model of glycolysis and the oxidative pentosephosphate pathway in developing Brassica napus embryos
    • Schwender J, Ohlrogge J.B, Shachar-Hill Y. A flux model of glycolysis and the oxidative pentosephosphate pathway in developing Brassica napus embryos. J. Biol. Chem. 278:2003;29442-29553
    • (2003) J. Biol. Chem. , vol.278 , pp. 29442-29553
    • Schwender, J.1    Ohlrogge, J.B.2    Shachar-Hill, Y.3
  • 35
    • 0033954794 scopus 로고    scopus 로고
    • Photosynthesis, sugars and the regulation of gene expression
    • Pego J.V, Kortstee A.J, Huijser C, Smeekens S.C.M. Photosynthesis, sugars and the regulation of gene expression. J. Exp. Bot. 51:2000;407-416
    • (2000) J. Exp. Bot. , vol.51 , pp. 407-416
    • Pego, J.V.1    Kortstee, A.J.2    Huijser, C.3    Smeekens, C.M.4
  • 36
    • 0033927041 scopus 로고    scopus 로고
    • A redox-responsive regulator of photosynthesis gene expression in the cyanobacterium Synechocystis sp. strain PCC 6803
    • Li H, Sherman L.A. A redox-responsive regulator of photosynthesis gene expression in the cyanobacterium Synechocystis sp. strain PCC 6803. J. Bacteriol. 182:2000;4268-4277
    • (2000) J. Bacteriol. , vol.182 , pp. 4268-4277
    • Li, H.1    Sherman, L.A.2
  • 37
    • 0034144409 scopus 로고    scopus 로고
    • Redox control of psbA gene expression in the cyanobacterium Synechocystis PCC 6803. Involvement of the cytochrome b6/f complex
    • Alfonso M, Perewoska I, Kirilovsky D. Redox control of psbA gene expression in the cyanobacterium Synechocystis PCC 6803. Involvement of the cytochrome b6/f complex. Plant Physiol. 122:2000;505-515
    • (2000) Plant Physiol. , vol.122 , pp. 505-515
    • Alfonso, M.1    Perewoska, I.2    Kirilovsky, D.3
  • 38
    • 0032544056 scopus 로고    scopus 로고
    • Glucose and ethylene signal transduction crosstalk revealed by an Arabidopsis glucose-insensitive mutant
    • Zhou L, Jang J.C, Tamara L.J, Sheen J. Glucose and ethylene signal transduction crosstalk revealed by an Arabidopsis glucose-insensitive mutant. Proc. Natl. Acad. Sci. USA. 95:1998;10294-10299
    • (1998) Proc. Natl. Acad. Sci. USA , vol.95 , pp. 10294-10299
    • Zhou, L.1    Jang, J.C.2    Tamara, L.J.3    Sheen, J.4
  • 41
    • 0035081595 scopus 로고    scopus 로고
    • Improved salt tolerance in transgenic tobacco expressing apoplastic yeast-derived invertase
    • Fukushima E, Arata Y, Endo T, Sonnewald U, Sato F. Improved salt tolerance in transgenic tobacco expressing apoplastic yeast-derived invertase. Plant Cell Physiol. 42:2001;245-249
    • (2001) Plant Cell Physiol. , vol.42 , pp. 245-249
    • Fukushima, E.1    Arata, Y.2    Endo, T.3    Sonnewald, U.4    Sato, F.5
  • 42
    • 0028425478 scopus 로고
    • Abscisic acid-induced heat tolerance in Bromus inermis cell-suspension cultures. Heat-stable, abscisic acid-responsive polypeptides in combination with sucrose confer enhanced stability
    • Robertson A.J, Ishikawa M, Gusta L.V, MacKenzie S.L. Abscisic acid-induced heat tolerance in Bromus inermis cell-suspension cultures. Heat-stable, abscisic acid-responsive polypeptides in combination with sucrose confer enhanced stability. Plant Physiol. 105:1994;181-190
    • (1994) Plant Physiol. , vol.105 , pp. 181-190
    • Robertson, A.J.1    Ishikawa, M.2    Gusta, L.V.3    MacKenzie, S.L.4
  • 43
    • 0346285592 scopus 로고    scopus 로고
    • Pesticide bioremediation: Genetic and ecological considerations
    • P.C. Kearney, T. Roberts (Eds.), Wiley and Sons, Chichester
    • D.R. Shelton, J.S. Karns, Pesticide bioremediation: genetic and ecological considerations, in: P.C. Kearney, T. Roberts (Eds.), Pesticide Remediation in Soils and Water, Wiley and Sons, Chichester, 1998, pp. 181-216.
    • (1998) Pesticide Remediation in Soils and Water , pp. 181-216
    • Shelton, D.R.1    Karns, J.S.2
  • 44
    • 0035193510 scopus 로고    scopus 로고
    • Environmental regulation of lateral root initiation in Arabidopsis
    • Malamy J.E, Ryan K.S. Environmental regulation of lateral root initiation in Arabidopsis. Plant Physiol. 127:2001;899-909
    • (2001) Plant Physiol. , vol.127 , pp. 899-909
    • Malamy, J.E.1    Ryan, K.S.2
  • 45
    • 85047685360 scopus 로고    scopus 로고
    • Arabidopsis seedling growth, storage lipid mobilization, and photosynthetic gene expression are regulated by carbon:nitrogen availability
    • Martin T, Oswald O, Graham I.A. Arabidopsis seedling growth, storage lipid mobilization, and photosynthetic gene expression are regulated by carbon:nitrogen availability. Plant Physiol. 128:2002;472-481
    • (2002) Plant Physiol. , vol.128 , pp. 472-481
    • Martin, T.1    Oswald, O.2    Graham, I.A.3
  • 47
    • 0035042867 scopus 로고    scopus 로고
    • Principles of redox control in photosynthesis gene expression
    • Pfannschmidt T, Allen J.F, Oelmüller R. Principles of redox control in photosynthesis gene expression. Physiol. Plant. 112:2001;1-9
    • (2001) Physiol. Plant. , vol.112 , pp. 1-9
    • Pfannschmidt, T.1    Allen, J.F.2    Oelmüller, R.3
  • 48
    • 0036738079 scopus 로고    scopus 로고
    • Engineering herbicide metabolism in tobacco and Arabidopsis with CYP76B1, a cytochrome P450 enzyme from Jerusalem artichoke
    • Didierjean L, Gondet L, Perkins R, Lau S.M.C, Schaller H, O'Keefe D.P, Werck-Reichhart D. Engineering herbicide metabolism in tobacco and Arabidopsis with CYP76B1, a cytochrome P450 enzyme from Jerusalem artichoke. Plant Physiol. 130:2002;1-11
    • (2002) Plant Physiol. , vol.130 , pp. 1-11
    • Didierjean, L.1    Gondet, L.2    Perkins, R.3    Lau, M.C.4    Schaller, H.5    O'Keefe, D.P.6    Werck-Reichhart, D.7
  • 49
    • 1642444687 scopus 로고    scopus 로고
    • Sucrose increases pathogenesis-related PR-2 expression in Arabidopsis thaliana through an SA-dependent but NPR1-independent signaling pathway
    • Thibaud M.C, Gineste S, Nussaume L, Robaglia C. Sucrose increases pathogenesis-related PR-2 expression in Arabidopsis thaliana through an SA-dependent but NPR1-independent signaling pathway. Plant Physiol. Biochem. 42:2004;81-88
    • (2004) Plant Physiol. Biochem. , vol.42 , pp. 81-88
    • Thibaud, M.C.1    Gineste, S.2    Nussaume, L.3    Robaglia, C.4


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.