臺灣博碩士論文加值系統

OSAG78為文心蘭之老化相關基因OSAGs（senescence-associated genes），以35S啟動子將OSAG78於阿拉伯芥中過量表現，其轉殖株具有體型較小、葉型變圓、莖變粗、雄蕊和雌蕊及花軸較粗短的外表型。本研究旨在探討過量表現OSAG78基因對於阿拉伯芥轉殖株之影響與其作用機制，期能應用於產生新品系文心蘭。
阿拉伯芥中與OSAG78蛋白質序列相似的其他基因受老化刺激的表現模式與OSAG78迥異，顯示OSAG78具有特殊的功能性。分析成熟與幼嫩簇生葉的生長比率發現，35S::OSAG78轉殖株具有生長不同的現象，可能與吉貝素(GA)之缺乏有關。然而，GA3之處理雖然可使轉殖株之開花時間提前，對植株之外表型及花期之延緩則無影響。惟經由GC-MS分析結果，轉殖株中的GA4與GA7含量的確較野生型阿拉伯芥為低；且轉殖株中GA20ox1與GA2ox1表現量下降，而GA3ox1表現量略微上升，顯示GA生合成途徑受影響。將相同生長階段之轉殖株與野生型阿拉伯芥離體葉片進行暗處理，分析葉綠素衰退情形與葉片老化之指標基因AtSAG12等表現量之結果，證實轉殖株的確具有特別之能力，且可延緩經由乙烯所誘導的現象，然而對於離層酸之誘導作用抑制效果並不顯著，對吉貝素之抑制的反應亦較不敏感。經由粗萃取蛋白質活性分析，則發現轉殖株之phospholipase A活性較野生型阿拉伯芥為高。而以大腸桿菌表現GST:OSAG78之重組蛋白質，亦發現OSAG78具有較高的lipase與phospholipase A的活性。且GST:OSAG78重組蛋白質大量累積在不可溶蛋白質沈澱物中，此一結果證實OSAG78蛋白質的性質與比對資料中極性趨向脂溶性之蛋白質類似。續以GFP融合於OSAG78蛋白質的C端並使其短暫表現於洋蔥之表皮細胞中，則證實OSAG78融合蛋白質表現在細胞膜附近。綜合本研究之試驗結果推測，OSAG78影響阿拉伯芥老化之作用乃因其過量表現lipase與phospholipase A活性，使得SAGs表現降低進而改變訊息傳導途徑所致。

OSAG78 is a senescence-associated gene cloned from Oncidium flower and was predicted as a lipid acyl-hydrolase protein. The full-length cDNA of OSAG78 was isolated and its ectopic expression of OSAG78, driven by 35S promoter in Arabidopsis, was analyzed. Compared with wild-type plants, the transgenic plants display smaller body size, stiffer inflorescence stem, thicker leaves, shorter siliques and more round-shaped flowers. Moreover, the 35S::OSAG78 transgenic lines display different flowering time. The mechanism of over-expressing OSAG78 in Arabidopsis is further studied in this research. According to RT-PCR assays, OSAG78 was regulated either during flowing time or after ethylene treatment in Oncidium. We found that OSAG78 showed the different expression pattern comparing to patatin-like proteins in Arabidopsis. Based on the leaf trichome distribution and phenotype of 35S::OSAG78 transgenic lines, the effects of OSAG78 in Arabidopsis were associated with an increase in the length of developmental phases of plant. It was assumed that the growth retardation may caused by GA deficiency or blocking in GA responses. The contents of bioactive GA4 and GA7, quantified by GC-MS, as well as the levels of AtGA20ox1 and AtGA2ox1 transcripts, quantified by real-time PCR, were lower than those in the wild-type plants. These results suggest that OSAG78 accumulation affects GA metabolism through the repression of biosynthetic steps catalyzed by GA 20-oxidase.
The content of chlorophyll and the expression of AtSAG in the detached leaves of transgenic and wild-type plants were investigated. In the leaves with or without ethylene, the expression of AtSAG was lower in transgenic lines than in wild-type plant. However, effects in transgenic plant were not observed after ABA treatment, and the application of GA and BAP decreases the expression of AtSAG12 in both transgenic and wild-type plants. Therefore, there should be another pathway to display effects of 35S::OSAG78 transgenic lines. By analysis of protein crude extracts, phospholipase A activity was higher in transgenic lines than in wild-type plants. Furthermore, a recombinant GST:OSAG78 fusion protein that overexpressed in Escherichia coli was accumulated in the insoluable protein pellet displaying lipase and phospholipase A activity. This result agrees with the previous prediction that OSAG78 protein is hydrophobic. To confirm the membrane association of OSAG78, a OSAG78:GFP fusion polypeptide was transiently expressed in onion (Allium cepa) epidermal cells, indicating that OSAG78 is localized at the cytoplasmic membrane. These results point out that over-expression of membrane-associated patatin protein OSAG78 that had phospholipase A activity affected GA biosynthesis in plant.

口試委員會審定
第一章 前言…………………………………………………………… 1
文心蘭切花老化………………………………………………………… 1
藉由突變株研究老化相關機制………………………………………… 1
與老化相關之植物荷爾蒙……………………………………………… 2
切花老化基因釣取與研究……………………………………………… 3
過量表現OSAG78於阿拉伯芥…………………………………………… 4
Patatin蛋白質之生理特性……………………………………………… 5
其他植物中的patatin-like 蛋白質 ………………………………… 6
PLA與訊息傳導…………………………………………………………… 7
GA生合成途徑…………………………………………………………… 8
研究目的與方向………………………………………………………… 9
第二章 材料與方法…………………………………………………… 10
一、材料………………………………………………………………… 10
二、常用實驗方法……………………………………………………… 10
三、阿拉伯芥葉片生長統計…………………………………………… 13
四、內生性GA含量測定………………………………………………… 13
五、葉綠素含量測量…………………………………………………… 14
六、RNA萃取…………………………………………………………… 14
七、RT-PCR和real-time PCR………………………………………… 15
八、質體構築與挑選…………………………………………………… 17
九、植物基因組DNA抽取……………………………………………… 18
十、阿拉伯芥花序浸潤轉殖與轉殖株篩選…………………………… 18
十一、基因槍暫時性表現OSAG78融合綠色螢光蛋白………………… 20
十二、暗處理誘導老化與施予植物荷爾蒙…………………………… 21
十三、植物蛋白質萃取………………………………………………… 21
十四、融合蛋白質表現………………………………………………… 22
十五、蛋白質活性測試………………………………………………… 27
十六、GUS組織染色分析……………………………………………… 28
十七、文心蘭轉殖……………………………………………………… 28
第三章 結果…………………………………………………………… 30
OSAG78為老化抑制基因………………………………………………… 30
OSAG78 在其他植物中的相似基因…………………………………… 30
阿拉伯芥OSAG78 homolog與細胞分裂素反應基因分析……………… 31
35S::OSAG78轉殖株具有生長遲緩的生理現象……………………… 31
過量表現OSAG78造成阿拉伯芥內生性GA含量下降…………………… 32
35S::OSAG78轉殖株具有延緩老化的生理現象……………………… 32
35S::OSAG78轉殖株花期延長並非GA缺乏所致……………………… 33
GA的缺乏並非造成35S::OSAG78轉殖株延緩葉片老化的主要原因… 33
35S::OSAG78轉殖株可減緩乙烯所誘導的老化現象………………… 34
過量表現OSAG78無法延緩離層酸所誘導的老化……………………… 35
OSAG78位於細胞膜附近………………………………………………… 35
轉殖株粗萃取蛋白質具有較高的lipase與phospholipase A活性……36
OSAG78表現蛋白質具有lipase與phospholipase A活性………………36
文心蘭轉殖……………………………………………………………… 37
第四章 討論…………………………………………………………… 39
OSAG78在植物老化中扮演的角色……………………………………… 39
OSAG78可能與養分累積有關…………………………………………… 40
過量表現OSAG78抑制GA生合成途徑造成生長遲緩…………………… 41
35S::OSAG78轉殖株花期延長與延緩老化機制相關………………… 43
過量表現OSAG78推測可延緩文心蘭切花老化………………………… 43
OSAG78具有PLA酵素活性與延緩老化相關…………………………… 44
結論……………………………………………………………………… 46
圖表……………………………………………………………………… 47
附錄……………………………………………………………………… 70
參考文獻………………………………………………………………… 71

徐偉恩 (2004). 文心蘭切花老化相關基因之篩選。國立台灣大學植物學研究所碩士論文。
張萌惠 (2001). 百日咳抗原於轉殖菸草之表現與老鼠口服免疫反應。國立台灣大學植物學研究所碩士論文。
黃肇家. (1998). 文心蘭切花之乙烯生成以及外加乙烯與去除花藥蓋對花朵品質之影響。中華農業研究 47: 125-134.
黃肇家, 黃慧穗, and 蔡金玉. (2005). 1-MCP 與農試文保一號之處理方法以及對外銷文心蘭切花保鮮之效果。園產品採後處理技術之研究與應用研討會專刊 191-198.
褚崇甫 (2006). 文心蘭類Lipid Acyl Hydrolase在阿拉伯芥中的表現與分析。國立台灣大學植物學研究所碩士論文。
Al-Saikhan, M.S., Howard, L.R., and J.C. Miller, J. (1995). Antioxidant activity and total phenolics in different genotypes of potato (Solanum tuberosum L.). J. Food Sci. 60: 341-344.
Alcazar, R., Garcia-Martinez, J.L., Cuevas, J.C., Tiburcio, A.F., and Altabella, T. (2005). Overexpression of ADC2 in Arabidopsis induces dwarfism and late-flowering through GA deficiency. Plant J. 43: 425-436.
Andrews, D.L., Beames, B., Summers, M.D., and Park, W.D. (1988). Characterization of the lipid acyl hydrolase activity of the major potato (Solanum tuberosum) tuber protein, patatin, by cloning and abundant expression in a baculovirus vector. Biochem J. 252: 199-206.
Becker, W., and Apel, K. (1993). Differences in gene expression between natural and artificially induced leaf senescence. Planta 189: 74-79.
Borochov, A., and Woodson, W. (1989). Physiology and biochemistry of flower petal senescence. Horticultural Reviews 11: 15-43.
Bovy, A.G., Angenent, G.C., Dons, H.J.M., and Altvorst, A.C.v. (1999). Heterologous expression of the Arabidopsis etr1-1 allele inhibits the senescence of carnation flowers. Mol. Breed 5: 301-308.
Butler, W., Cook, L., and Vayda, M.E. (1990). Hypoxic stress inhibits multiple aspects of the potato tuber wound response. Plant Physiol. 93: 264-270.
Carrera, E., Jackson, S.D., and Prat, S. (1999). Feedback control and diurnal regulation of gibberellin 20-oxidase transcript levels in potato. Plant Physiol. 119: 765-774.
Carrera, E., Bou, J., Garcia-Martinez, J.L., and Prat, S. (2000). Changes in GA 20-oxidase gene expression strongly affect stem length, tuber induction and tuber yield of potato plants. Plant J. 22: 247-256.
Chang, H., Jones, M.L., Banowetz, G.M., and Clark, D.G. (2003). Overproduction of cytokinins in petunia flowers transformed with P(SAG12)-IPT delays corolla senescence and decreases sensitivity to ethylene. Plant Physiol. 132: 2174-2183.
Chen, F.C., and Chen, T.C. (1998). Effect of salt strength and organic additives on the in vitro growth of protocorm-like-bodies and plantlets of Oncidium Gower Ramsey. J. Chinese Soc. Hort. Sci. 44: 403-412.
Chen, J.J., Janssen, B.J., Williams, A., and Sinha, N. (1997). A gene fusion at a homeobox locus: alterations in leaf shape and implications for morphological evolution. Plant Cell 9: 1289-1304.
Chiang, H.H., Hwang, I., and Goodman, H.M. (1995). Isolation of the Arabidopsis GA4 locus. Plant Cell 7: 195-201.
Chin-Atkins, A.N., Craig, S., Hocart, C.H., Dennis, E.S., and Chaudhury, A.M. (1996). Increased endogenous cytokinin in the Arabidopsis amp1 mutant corresponds with de-etiolation responses. Planta 198: 549-556.
Derkx, M.P.M., Vermeer, E., and Karsse, C.M. (1994). Gibberellins in seeds of Arabidopsis thaliana: biological activities, identification and effects of light and chilling on endogenous levels. Plant Growth Regulation 15: 223-234.
Dhondt, S., Geoffroy, P., Stelmach, B.A., Legrand, M., and Heitz, T. (2000). Soluble phospholipase A2 activity is induced before oxylipin accumulation in tobacco mosaic virus-infected tobacco leaves and is contributed by patatin-like enzymes. Plant J. 23: 431-440.
Dhondt, S., Gouzerh, G., Muller, A., Legrand, M., and Heitz, T. (2002). Spatio-temporal expression of patatin-like lipid acyl hydrolases and accumulation of jasmonates in elicitor-treated tobacco leaves are not affected by endogenous levels of salicylic acid. Plant J. 32: 749-762.
Eastmond, P.J. (2006). SUGAR-DEPENDENT1 encodes a patatin domain triacylglycerol lipase that initiates storage oil breakdown in germinating Arabidopsis seeds. Plant Cell 18: 665-675.
Eriksson, S., Bohlenius, H., Moritz, T., and Nilsson, O. (2006). GA4 is the active gibberellin in the regulation of LEAFY transcription and Arabidopsis floral initiation. Plant Cell 18: 2172-2181.
Fan, L., Zheng, S., and Wang, X. (1997). Antisense suppression of phospholipase D alpha retards abscisic acid- and ethylene-promoted senescence of postharvest Arabidopsis leaves. Plant Cell 9: 2183-2196.
Farmer, E.E., and Ryan, C.A. (1992). Octadecanoid precursors of jasmonic acid activate the synthesis of wound-inducible proteinase inhibitors. Plant Cell 4: 129-134.
Galliard, T. (1971). The enzymic deacylation of phospholipids and galactolipids in plants. Purification and properties of a lipolytic acyl-hydrolase from potato tubers. Biochem J. 121: 379-390.
Gan, S., and Amasino, R.M. (1995). Inhibition of leaf senescence by autoregulated production of cytokinin. Science 270: 1986-1988.
Gan, S., and Amasino, R.M. (1997). Making sense of senescence (molecular genetic regulation and manipulation of leaf senescence). Plant Physiol. 113: 313-319.
Gubler, F., Kalla, R., Roberts, J.K., and Jacobsen, J.V. (1995). Gibberellin-regulated expression of a myb gene in barley aleurone cells: evidence for Myb transactivation of a high-pI alpha-amylase gene promoter. Plant Cell 7: 1879-1891.
Hajdukiewicz, P., Svab, Z., and Maliga, P. (1994). The small, versatile pPZP family of Agrobacterium binary vectors for plant transformation. Plant Mol. Biol. 25: 989-994.
Hannapel, D.J., Miller, J.C., and Park, W.D. (1985). Regulation of potato tuber protein accumulation by gibberellic acid. Plant Physiol. 78: 700-703.
Hay, A., Kaur, H., Phillips, A., Hedden, P., Hake, S., and Tsiantis, M. (2002). The gibberellin pathway mediates KNOTTED1-type homeobox function in plants with different body plans. Curr. Biol. 12: 1557-1565.
Hedden, P., and Phillips, A.L. (2000). Gibberellin metabolism: new insights revealed by the genes. Trends Plant Sci. 5: 523-530.
Holk, A., Rietz, S., Zahn, M., Quader, H., and Scherer, G.F. (2002). Molecular identification of cytosolic, patatin-related phospholipases A from Arabidopsis with potential functions in plant signal transduction. Plant Physiol. 130: 90-101.
Hortensteiner, S., and Feller, U. (2002). Nitrogen metabolism and remobilization during senescence. J. Exp. Bot. 53: 927-937.
Huang, S., Cerny, R.E., Bhat, D.S., and Brown, S.M. (2001). Cloning of an Arabidopsis patatin-like gene, STURDY, by activation T-DNA tagging. Plant Physiol. 125: 573-584.
Jefferson, R.A., Kavanagh, T.A., and Bevan, M.W. (1987). GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants. EMBO J. 6: 3901-3907.
Jung, K.M., and Kim, D.K. (2000). Purification and characterization of a membrane-associated 48-kilodalton phospholipase A2 in leaves of broad bean. Plant Physiol. 123: 1057-1067.
Knowles, N.R., and Knowles, L.O. (1989). Correlations between electrolyte leakage and degree of saturation of polar lipids from aged potato (Solanum tuberosum L.) tuber tissue. Ann. Bot. 63: 331-338.
Koornneef, M., and van der Veen, J.H. (1980). Induction and analysis of gibberellin sensitive mutants in Arabidopsis thaliana. Heynh. Theor. Appl. Genet. 58: 257-263.
Koornneef, M., Hanhart, C.J., and van der Veen, J.H. (1991). A genetic and physiological analysis of late owering mutants in Arabidopsis thaliana. Mol. Gen. Genet. 229: 57-66.
Koornneef, M., Alonso-Blanco, C., Peeters, A.J., and Soppe, W. (1998). Genetic control of owering time in Arabidopsis. Annu. Rev. Plant Physiol. Plant Mol. Biol. 49: 345-370.
Kostyal, D.A., Hickey, V.L., Noti, J.D., Sussman, G.L., and Beezhold, D.H. (1998). Cloning and characterization of a latex allergen (Hev b 7): homology to patatin, a plant PLA2. Clin. Exp. Immunol. 112: 355-362.
Kumar, G., and Knowles, N.R. (1993). Changes in lipid peroxidation and lipolytic and free-radical scavenging enzyme activities during aging and sprouting of potato (Solanum tuberosum) seed-tubers. Plant Physiol. 102: 115-124.
Kumar, G.N., Houtz, R.L., and Knowles, N.R. (1999). Age-induced protein modifications and increased proteolysis in potato seed-tubers. Plant Physiol. 119: 89-100.
Kusaba, S., Fukumoto, M., Honda, C., Yamaguchi, I., Sakamoto, T., and Kano-Murakami, Y. (1998a). Decreased GA1 content caused by the overexpression of OSH1 is accompanied by suppression of GA 20-oxidase gene expression. Plant Physiol. 117: 1179-1184.
Kusaba, S., Kano-Murakami, Y., Matsuoka, M., Tamaoki, M., Sakamoto, T., Yamaguchi, I., and Fukumoto, M. (1998b). Alteration of hormone levels in transgenic tobacco plants overexpressing the rice homeobox gene OSH1. Plant Physiol. 116: 471-476.
La Camera, S., Geoffroy, P., Samaha, H., Ndiaye, A., Rahim, G., Legrand, M., and Heitz, T. (2005). A pathogen-inducible patatin-like lipid acyl hydrolase facilitates fungal and bacterial host colonization in Arabidopsis. Plant J. 44: 810-825.
Lee, H.Y., Bahn, S.C., Shin, J.S., Hwang, I., Back, K., Doelling, J.H., and Ryu, S.B. (2005). Multiple forms of secretory phospholipase A2 in plants. Prog. Lipid Res. 44: 52-67.
Liau, C.H., You, S.J., Prasad, V., Hsiao, H.H., Lu, J.C., Yang, N.S., and Chan, M.T. (2003). Agrobacterium tumefaciens-mediated transformation of an Oncidium orchid. Plant Cell Rep. 21: 993-998.
Lichtenthaler, H.K. (1987). Chlorophylls and carotenoids: pigments of photosynthetic biomembranes. Methods Enzymol. 148: 349-382.
Liu, Y.-W., Chuan-Hsiao, H., Mei-Hsien, L., Feng-Lin, H., and Wen-Chi, H. (2003). Patatin, the tuber storage protein of potato (Solanum tuberosum L.), exhibits antioxidant activity in vitro. J. Agric. Food Chem. 51: 4389-4393.
Lohman, K.N., Gan, S., John, M.C., and Amasino, R.M. (1994). Molecular analysis of natural leaf senescence in Arabidopsis thaliana. Physiol. Plant. 92: 322-328.
Martin-Trillo, M., Lazaro, A., Poethig, R.S., Gomez-Mena, C., Pineiro, M.A., Martinez-Zapater, J.M., and Jarillo, J.A. (2006). EARLY IN SHORT DAYS 1 (ESD1) encodes ACTIN-RELATED PROTEIN 6 (AtARP6), a putative component of chromatin remodelling complexes that positively regulates FLC accumulation in Arabidopsis. Development 133: 1241-1252.
Matos, A.R., d''Arcy-Lameta, A., Franca, M., Petres, S., Edelman, L., Kader, J., Zuily-Fodil, Y., and Pham-Thi, A.T. (2001). A novel patatin-like gene stimulated by drought stress encodes a galactolipid acyl hydrolase. FEBS Lett. 491: 188-192.
Meijer, H.J., and Munnik, T. (2003). Phospholipid-based signaling in plants. Annu. Rev. Plant Biol. 54: 265-306.
Moreau, R.A. (1989). An evaluation of NBD-phospholipids as sbustrates for the measurement of phsohplipase and lipase activities. Lipids 24: 691-699.
Munnik, T., Irvine, R.F., and Musgrave, A. (1998). Phospholipid signalling in plants. Biochim. Biophys. Acta. 1389: 222-272.
Nam, H.G. (1997). The molecular genetic analysis of leaf senescence. Curr. Opin. Biotechnol. 8: 200-207.
Narvaez-Vasquez, J., Florin-Christensen, J., and Ryan, C.A. (1999). Positional specificity of a phospholipase A activity induced by wounding, systemin, and oligosaccharide elicitors in tomato leaves. Plant Cell 11: 2249-2260.
Oh, S.A., Lee, S.Y., Chung, I.K., Lee, C.H., and Nam, H.G. (1996). A senescence-associated gene of Arabidopsis thaliana is distinctively regulated during natural and artificially induced leaf senescence. Plant Mol. Biol. 30: 739-754.
Ori, N., Juarez, M.T., Jackson, D., Yamaguchi, J., Banowetz, G.M., and Hake, S. (1999). Leaf senescence is delayed in tobacco plants expressing the maize homeobox gene knotted1 under the control of a senescence-activated promoter. Plant Cell 11: 1073-1080.
Paiva, E., Lister, R.M., and Park, W.D. (1983). Induction and accumulation of major tuber proteins of potato in stems and petioles. Plant Physiol. 71: 161-168.
Panavas, T., and Rubinstein, B. (1998). Oxidative events during programmed cell death of daylily (Hemerocallis hybrid) petals. Plant Sci. 133: 125-138.
Park, J.H., Oh, S.A., Kim, Y.H., Woo, H.R., and Nam, H.G. (1998). Differential expression of senescence-associated mRNAs during leaf senescence induced by different senescence-inducing factors in Arabidopsis. Plant Mol. Biol. 37: 445-454.
Parnis, A., Cohen, O., Gutfinger, T., Hareven, D., Zamir, D., and Lifschitz, E. (1997). The dominant developmental mutants of tomato, Mouse-ear and Curl, are associated with distinct modes of abnormal transcriptional regulation of a Knotted gene. Plant Cell 9: 2143-2158.
Pencreac''h, G., and Baratti, J.C. (1996). Hydrolysis of p-nitrophenyl palmitate in n-heptane by the Pseudomonas cepacia lipase: A simple test for the determination of lipase activity in organic media. Enzyme Microb. Technol. 18: 417-422.
Phillips, A.L., Ward, D.A., Uknes, S., Appleford, N.E., Lange, T., Huttly, A.K., Gaskin, P., Graebe, J.E., and Hedden, P. (1995). Isolation and expression of three gibberellin 20-oxidase cDNA clones from Arabidopsis. Plant Physiol. 108: 1049-1057.
Pikaard, C.S., Brusca, J.S., Hannapel, D.J., and Park, W.D. (1987). The two classes of genes for the major potato tuber protein, patatin, are differentially expressed in tubers and roots. Nucleic Acids Res. 15: 1979-1994.
Racusen, D. (1984). Lipid acyl hydrolase of patatin. Can. J. Bot. 62: 1640-1644.
Racusen, D. (1986). Esterase specificity of patatin from two potato cultivars. Can. J. Bot. 64.
Racusen, D., and Foote, M. (1980). A major soluble glycoprotein of potato tubers. J. Food Biochem. 4: 43-52.
Ren, G., An, K., Liao, Y., Zhou, X., Cao, Y., Zhao, H., Ge, X., and Kuai, B. (2007). Identification of a novel chloroplast protein AtNYE1 regulating chlorophyll degradation during leaf senescence in Arabidopsis. Plant Physiol. 144: 1429-1441.
Rietz, S., Holk, A., and Scherer, G.F. (2004). Expression of the patatin-related phospholipase A gene AtPLA IIA in Arabidopsis thaliana is up-regulated by salicylic acid, wounding, ethylene, and iron and phosphate deficiency. Planta 219: 743-753.
Riou-Khamlichi, C., Huntley, R., Jacqmard, A., and Murray, J.A. (1999). Cytokinin activation of Arabidopsis cell division through a D-type cyclin. Science 283: 1541-1544.
Rocha-Sosa, M., Sonnewald, U., Frommer, W., Stratmann, M., Schell, J., and Willmitzer, L. (1989). Both developmental and metabolic signals activate the promoter of a class I patatin gene. EMBO J. 8: 23-29.
Ronen, M., and Mayak, S. (1981). Interrelationship between Abscisic Acid and Ethylene in the Control of Senescence Processes in Carnation Flowers. J. Exp. Bot. 32: 759-765.
Rosenvasser, S., Mayak, S., and Friedman, H. (2006). Increase in reactive oxygen species (ROS) and in senescence-associated gene transcript (SAG) levels during dark-induced senescence of Pelargonium cuttings, and the effect of gibberellic acid. Plant Sci. 170: 873-879.
Rosin, F.M., Hart, J.K., Horner, H.T., Davies, P.J., and Hannapel, D.J. (2003). Overexpression of a knotted-like homeobox gene of potato alters vegetative development by decreasing gibberellin accumulation. Plant Physiol. 132: 106-117.
Ross, J.J., Reid, J.B., Gaskin, P., and Macmillan, J. (1989). Internode length in Pisum.Estimation of GA1 levels in genotypes Le, le and led. Physiol. Plant. 76: 173-176.
Ryu, S.B. (2004). Phospholipid-derived signaling mediated by phospholipase A in plants. Trends Plant Sci. 9: 229-235.
Ryu, S.B., and Wang, X. (1995). Expression of phospholipase D during castor bean leaf senescence. Plant Physiol. 108: 713-719.
Ryu, S.B., and Palta, J.P. (2000). Specific inhibition of rat brain phospholipase D by lysophospholipids. J. Lipid Res. 41: 940-944.
Ryu, S.B., Karlsson, B.H., Ozgen, M., and Palta, J.P. (1997). Inhibition of phospholipase D by lysophosphatidylethanolamine, a lipid-derived senescence retardant. Proc. Natl. Acad. Sci. USA 94: 12717-12721.
Sakamoto, T., Kamiya, N., Ueguchi-Tanaka, M., Iwahori, S., and Matsuoka, M. (2001). KNOX homeodomain protein directly suppresses the expression of a gibberellin biosynthetic gene in the tobacco shoot apical meristem. Genes Dev. 15: 581-590.
Sambrook, J., Fritsch, E.F., and Maniatis, T. (1989). Molecular Cloning: A Laboratory Manual, 2nd ed. (Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press).
Sang, Y., Cui, D., and Wang, X. (2001). Phospholipase D and phosphatidic acid-mediated generation of superoxide in Arabidopsis. Plant Physiol. 126: 1449-1458.
Scott, A., Wyatt, S., Tsou, P.L., Robertson, D., and Allen, N.S. (1999). Model system for plant cell biology: GFP imaging in living onion epidermal cells. Biotechniques 26: 1125, 1128-1132.
Strickland, J.A., Orr, G.L., and Walsh, T.A. (1995). Inhibition of diabrotica larval growth by patatin, the lipid acyl hydrolase from potato tubers. Plant Physiol. 109: 667-674.
Taiz, L., and Zeiger, E. (2002). Plant Physiology, 3rd ed. (Sinauer Associates, Inc.).
Talon, M., Koornneef, M., and Zeevaart, J.A. (1990). Endogenous gibberellins in Arabidopsis thaliana and possible steps blocked in the biosynthetic pathways of the semidwarf ga4 and ga5 mutants. Proc. Natl. Acad. Sci. USA 87: 7983-7987.
Tamaoki, M., Kusaba, S., Kano-Murakami, Y., and Matsuoka, M. (1997). Ectopic expression of a tobacco homeobox gene, NTH15, dramatically alters leaf morphology and hormone levels in transgenic tobacco. Plant Cell Physiol. 38: 917-927.
Tamura, K., Dudley, J., Nei, M., and Kumar, S. (2007). MEGA4: molecular evolutionary genetics analysis (MEGA) software version 4.0. Mol. Biol. Evol. 24: 1596-1599.
Tanaka-Ueguchi, M., Itoh, H., Oyama, N., Koshioka, M., and Matsuoka, M. (1998). Over-expression of a tobacco homeobox gene, NTH15, decreases the expression of a gibberellin biosynthetic gene encoding GA 20-oxidase. Plant J. 15: 391-400.
Telfer, A., Bollman, K.M., and Poethig, R.S. (1997). Phase change and the regulation of trichome distribution in Arabidopsis thaliana. Development 124: 645-654.
Thomas, H., and Howarth, C.J. (2000). Five ways to stay green. J. Exp. Bot. 51: 329-337.
Torii, K.U., Mitsukawa, N., Oosumi, T., Matsuura, Y., Yokoyama, R., Whittier, R.F., and Komeda, Y. (1996). The Arabidopsis ERECTA gene encodes a putative receptor protein kinase with extracellular leucine-rich repeats. Plant Cell 8: 735-746.
Vancanneyt, G., Sonnewald, U., Hofgen, R., and Willmitzer, L. (1989). Expression of a patatin-like protein in the anthers of potato and sweet pepper flowers. Plant Cell 1: 533-540.
Veen, H. (1979). Effects of silver on ethylene synthesis and action in cut carnations. Planta 145: 467-470.
Wang, X. (2004). Lipid signaling. Curr. Opin. Plant Biol. 7: 329-336.
Wardale, D.A. (1980). Lipid-degrading enzymes from potato tubers. Phytochemistry 19: 173-177.
Weaver, L.M., and Amasino, R.M. (2001). Senescence is induced in individually darkened Arabidopsis leaves, but inhibited in whole darkened plants. Plant Physiol. 127: 876-886.
Wenzler, H.C., Information, C., Mignery, G.A., Information, C., Fisher, L.M., Information, C., and Park, W.D. (1989). Analysis of a chimeric class-I patatin-GUS gene in transgenic potato plants: High-level expression in tubers and sucrose-inducible expression in cultured leaf and stem explants. Plant Mol. Biol. 12: 41-50.
Zabrouskov, V., Kumar, G.N.M., Spychalla, J.P., and Knowles, N.R. (2002). Oxidative metabolism and the physiological age of seed potatoes are affected by increased α-linolenate content. Physiol. Plant. 116: 172-185.
Zimmermann, P., Hirsch-Hoffmann, M., Hennig, L., and Gruissem, W. (2004). GENEVESTIGATOR. Arabidopsis microarray database and analysis toolbox. Plant Physiol. 136: 2621-2632.