脯氨酸转运相关基因的研究进展

doi:10.11983/CBB17192

摘要/Abstract

摘要： 作为植物中普遍存在的一种逆境适应机制, 脯氨酸积累一直被认为是其合成和降解调控的结果。然而越来越多的研究表明, 脯氨酸转运也可能在其积累过程中起重要作用。在植物中, 有多个氨基酸转运蛋白家族, 如氨基酸通透酶家族(AAPs)、赖氨酸组氨酸转运蛋白家族(LHTs)和脯氨酸转运蛋白家族(ProTs)参与脯氨酸在各个器官间的运输。该文对参与脯氨酸运输的基因家族成员的表达模式、生理功能及表达调控进行了综述, 以期为脯氨酸运输与积累在植物抗逆方面的研究提供参考。

关键词: 脯氨酸, 脯氨酸转运, 氨基酸转运蛋白, 表达调控

Abstract: As a wide-spread stress adaption in plants, proline accumulation is thought to result from increased biosynthesis and decreased degradation. However, accumulating reports showed that proline transport also plays a role in stress-induced proline accumulation. In plants, several amino acid transporter protein families, such as AAPs, LHTs and ProTs, can transport proline. In this review, we summarize the expression pattern, function and expression regulation of these families in terms of proline transport, with an aim to provide some useful information on proline transport and accumulation research in plants.

Key words: proline, proline transport, amino acid transporter protein, expression regulation

陈颖, 王婷, 华学军. 脯氨酸转运相关基因的研究进展. 植物学报, 2018, 53(6): 754-763.

Chen Ying, Wang Ting, Hua Xuejun. Recent Progress in Research of Proline Transport Genes. Chinese Bulletin of Botany, 2018, 53(6): 754-763.

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.chinbullbotany.com/CN/10.11983/CBB17192

https://www.chinbullbotany.com/CN/Y2018/V53/I6/754

图/表 2

参考文献 79

[1]	全先庆, 张渝洁, 单雷, 毕玉平 (2007). 高等植物脯氨酸代谢研究进展. 生物技术通报 (1), 14-18. DOI URL
[2]	赵瑞雪, 朱慧森, 程钰宏, 董宽虎 (2008). 植物脯氨酸及其合成酶系研究进展. 草业科学 25, 90-97.
[3]	Andréasson C, Neve EPA, Ljungdahl PO (2004). Four permeases import proline and the toxic proline analogue azetidine-2-carboxylate into yeast.Yeast 21, 193-199. DOI URL PMID
[4]	Bäumlein H, Nagy I, Villarroel R, Inzé D, Wobus U (1992). Cis-analysis of a seed protein gene promoter: the conser- vative RY repeat CATGCATG within the legumin box is essential for tissue-specific expression of a legumin gene. Plant J 2, 233-239.
[5]	Breitkreuz KE, Shelp BJ, Fischer WN, Schwacke R, Rentsch D (1999). Identification and characterization of GABA, proline and quaternary ammonium compound transporters fromArabidopsis thaliana. FEBS Lett 450, 280-284. DOI URL PMID
[6]	Cassab GI (1998). Plant cell wall proteins.Annu Rev Plant Physiol Plant Mol Biol 49, 281-309. DOI URL
[7]	Chang HC (1998). NAT2/AAP1 as A Prototypical Example of the AAP amino Acid Transporter Gene Family: From Protein Topology to Regulation of Gene Expression. Ph.D. thesis. Urbana: University of Illinois at Urbana-Cham- paign. pp. 33-52.
[8]	Chen JG, Zhang YQ, Wang CP, Lü WT, Jin JB, Hua XJ (2011). Proline induces calcium-mediated oxidative burst and salicylic acid signaling.Amino Acids 40, 1473-1484. DOI URL PMID
[9]	Chen LS, Bush DR (1997). LHT1, a lysine- and histidine- specific amino acid transporter in Arabidopsis.Plant Phy- siol 115, 1127-1134. DOI URL PMID
[10]	Chen NH, Reith MEA, Quick MW (2004). Synaptic uptake and beyond: the sodium- and chloride-dependent neuro- transmitter transporter family SLC6.Pflügers Arch 447, 519-531. DOI URL PMID
[11]	Couturier J, de Fay E, Fitz M, Wipf D, Blaudez D, Chalot M (2010). PtAAP11, a high affinity amino acid transporter specifically expressed in differentiating xylem cells of poplar.J Exp Bot 61, 1671-1682. DOI URL PMID
[12]	Csonka LN (1989). Physiological and genetic responses of bacteria to osmotic-stress.Microbiol Rev 53, 121-147. DOI URL PMID
[13]	Deuschle K, Funck D, Forlani G, Stransky H, Biehl A, Leister D, van der Graaff E, Kunze R, Frommer WB (2004). The role of Δ1-pyrroline-5-carboxylate dehydro genase in proline degradation.Plant Cell 16, 3413-3425. DOI URL
[14]	Di Martino C, Pizzuto R, Pallotta ML, De Santis A, Passarella S (2006). Mitochondrial transport in proline catabolism in plants: the existence of two separate trans- locators in mitochondria isolated from durum wheat seed- lings.Planta 223, 1123-1133. DOI URL PMID
[15]	Fischer WN, André B, Rentsch D, Krolkiewicz S, Tegeder M, Breitkreuz K, Frommer WB (1998). Amino acid transport in plants.Trends Plant Sci 3, 188-195. DOI URL
[16]	Fischer WN, Kwart M, Hummel S, Frommer WB (1995). Substrate-specificity and expression profile of amino-acid transporters (AAPs) in Arabidopsis.J Biol Chem 270, 16315-16320. DOI URL PMID
[17]	Fischer WN, Loo DDF, Koch W, Ludewig U, Boorer KJ, Tegeder M, Rentsch D, Wright EM, Frommer WB (2002). Low and high affinity amino acid H+-cotransporters for cellular import of neutral and charged amino acids.Plant J 29, 717-731. DOI URL
[18]	Foster J, Lee YH, Tegeder M (2008). Distinct expression of members of the LHT amino acid transporter family in flowers indicates specific roles in plant reproduction.Sex Plant Reprod 21, 143-152. DOI URL
[19]	Frommer WB, Hummel S, Riesmeier JW (1993). Expres- sion cloning in yeast of a cDNA encoding a broad speci- ficity amino acid permease from Arabidopsis thaliana. Proc Natl Acad Sci USA 90, 5944-5948.
[20]	Girousse C, Bournoville R, Bonnemain JL (1996). Water deficit-induced changes in concentration in proline and some other amino acids in the phloem sap of Alfalfa.Plant Physiol 111, 109-113. DOI URL PMID
[21]	Grallath S, Weimar T, Meyer A, Gumy C, Suter-Grote- meyer M, Neuhaus JM, Rentsch D (2005). The AtProT family. Compatible solute transporters with similar sub- strate specificity but differential expression patterns.Plant Physiol 137, 117-126. DOI URL PMID
[22]	Grenson M, Hou C, Crabeel M (1970). Multiplicity of the amino acid permeases in Saccharomyces cerevisiae. IV. Evidence for a general amino acid permease. J Bacteriol 103, 770-777.
[23]	Guether M, Volpe V, Balestrini R, Requena N, Wipf D, Bonfante P (2011). LjLHT1.2-a mycorrhiza-inducible plant amino acid transporter from Lotus japonicus. Biol Fertil Soils 47, 925-936.
[24]	Guo MJ (2004). Molecular and Genomic Analysis of Nitrogen Regulation of Amino Acid Permease I (AAP1) in Arabi- dopsis. Ph.D. thesis. Urbana: University of Illinois at Urba- na-Champaign. pp. 90-102.
[25]	Hammes UZ, Nielsen E, Honaas LA, Taylor CG, Schacht- man DP (2006). AtCAT6, a sink-tissue-localized transpor- ter for essential amino acids in Arabidopsis.Plant J 48, 414-426. DOI URL PMID
[26]	Hatanaka T, Hatanaka Y, Setou M (2006). Regulation of amino acid transporter ATA2 by ubiquitin ligase Nedd4-2.J Biol Chem 281, 35922-35930. DOI URL PMID
[27]	Heazlewood JL, Durek P, Hummel J, Selbig J, Weckwerth W, Walther D, Schulze WX (2008). PhosPhAt: a database of phosphorylation sites in Arabidopsis thaliana and a plant-specific phosphorylation site predictor. Nucleic Acids Res 36, D1015-D1021.
[28]	Hirner A, Ladwig F, Stransky H, Okumoto S, Keinath M, Harms A, Frommer WB, Koch W (2006). Arabidopsis LHT1 is a high-affinity transporter for cellular amino acid uptake in both root epidermis and leaf mesophyll.Plant Cell 18, 1931-1946. DOI URL PMID
[29]	Hu CAA, Delauney AJ, Verma DPS (1992). A bifunctional enzyme (Delta-1-pyrroline-5-carboxylate synthetase) cataly- zes the first two steps in proline biosynthesis in plants.Proc Natl Acad Sci USA 89, 9354-9358. DOI URL PMID
[30]	Hunt E, Gattolin S, Newbury HJ, Bale JS, Tseng HM, Barrett DA, Pritchard J (2010). A mutation in amino acid permease AAP6 reduces the amino acid content of the Arabidopsis sieve elements but leaves aphid herbivores unaffected.J Exp Bot 61, 55-64. DOI URL PMID
[31]	Igarashi Y, Yoshiba Y, Takeshita T, Nomura S, Otomo J, Yamaguchi-Shinozaki K, Shinozaki K (2000). Molecular cloning and characterization of a cDNA encoding proline transporter in rice.Plant Cell Physiol 41, 750-756. DOI URL PMID
[32]	Jauniaux JC, Vandenbol M, Vissers S, Broman K, Grenson M (1987). Nitrogen catabolite regulation of pro- line permease in Saccharomyces cerevisiae: cloning of the PUT4 gene and study of PUT4 RNA levels in wild-type and mutant strains. Eur J Biochem 164, 601-606.
[33]	Kiyosue T, Yoshiba Y, Yamaguchi-Shinozaki K, Shinoz- aki K (1996). A nuclear gene encoding mitochondrial proline dehydrogenase, an enzyme involved in proline metabolism, is upregulated by proline but downregulated by dehydration in Arabidopsis.Plant Cell 8, 1323-1335. DOI URL PMID
[34]	Koch W, Kwart M, Laubner M, Heineke D, Stransky H, Frommer WB, Tegeder M (2003). Reduced amino acid content in transgenic potato tubers due to antisense inhibition of the leaf H+/amino acid symporter StAAP1.Plant J 33, 211-220. DOI URL
[35]	Lasko PF, Brandriss MC (1981). Proline transport in Saccharomyces cerevisiae. J Bacteriol 148, 241-247.
[36]	Lee YH, Foster J, Chen J, Voll LM, Weber APM, Tegeder M (2007). AAP1 transports uncharged amino acids into roots of Arabidopsis.Plant J 50, 305-319. DOI URL PMID
[37]	Lee YH, Tegeder M (2004). Selective expression of a novel high-affinity transport system for acidic and neutral amino acids in the tapetum cells of Arabidopsis flowers.Plant J 40, 60-74. DOI URL PMID
[38]	Lehmann S, Funck D, Szabados L, Rentsch D (2010). Proline metabolism and transport in plant development.Amino Acids 39, 949-962. DOI URL PMID
[39]	Liu X, Bush DR (2006). Expression and transcriptional regulation of amino acid transporters in plants.Amino Acids 30, 113-120. DOI URL PMID
[40]	Lv WT, Lin B, Zhang M, Hua XJ (2011). Proline accumula- tion is inhibitory to Arabidopsis seedlings during heat stress.Plant Physiol 156, 1921-1933. DOI URL
[41]	Marella HH, Nielsen E, Schachtman DP, Taylor CG (2013). The amino acid permeases AAP3 and AAP6 are involved in root-knot nematode parasitism of Arabidopsis.Mol Plant Microbe Interact 26, 44-54. DOI URL PMID
[42]	Matskevitch I, Wagner CA, Stegen C, Bröer S, Noll B, Risler T, Kwon HM, Handler JS, Waldegger S, Busch AE, Lang F (1999). Functional characterization of the betaine/γ-aminobutyric acid transporter BGT-1 expressed in Xenopus oocytes. J Biol Chem 274, 16709-16716. DOI URL PMID
[43]	Miranda M, Borisjuk L, Tewes A, Heim U, Sauer N, Wobus U, Weber H (2001). Amino acid permeases in developing seeds of Vicia faba L: expression precedes storage protein synthesis and is regulated by amino acid supply. Plant J 28, 61-71. DOI URL PMID
[44]	Morbach S, Krämer R (2002). Body shaping under water stress: osmosensing and osmoregulation of solute trans- port in bacteria.Chembiochem 3, 384-397. DOI URL PMID
[45]	Okumoto S, Schmidt R, Tegeder M, Fischer WN, Rentsch D, Frommer WB, Koch W (2002). High affinity amino acid transporters specifically expressed in xylem parenchyma and developing seeds of Arabidopsis.J Biol Chem 277, 45338-45346. DOI URL
[46]	Ortiz-Lopez A, Chang HC, Bush DR (2000). Amino acid transporters in plants.Biochim Biophys Acta 1465, 275-280. DOI URL PMID
[47]	Peng B, Kong HL, Li YB, Wang LQ, Zhong M, Sun L, Gao GJ, Zhang QL, Luo LJ, Wang GW, Xie WB, Chen JX, Yao W, Peng Y, Lei L, Lian XM, Xiao JH, Xu CG, Li XH, He YQ (2014). OsAAP6 functions as an important regu- lator of grain protein content and nutritional quality in rice. Nat Commun 5, 4847.
[48]	Perchlik M, Foster J, Tegeder M (2014). Different and overlapping functions of Arabidopsis LHT6 and AAP1 transporters in root amino acid uptake.J Exp Bot 65, 5193-5204. DOI URL PMID
[49]	Popova OV, Dietz KJ, Golldack D (2003). Salt-dependent expression of a nitrate transporter and two amino acid transporter genes in Mesembryanthemum crystallinum. Plant Mol Biol 52, 569-578.
[50]	Pratelli R, Pilot G (2014). Regulation of amino acid meta- bolic enzymes and transporters in plants.J Exp Bot 65, 5535-5556. DOI URL PMID
[51]	Regenberg B, Düring-Olsen L, Kielland-Brandt MC, Holmberg S (1999). Substrate specificity and gene exp- ression of the amino-acid permeases in Saccharomyces cerevisiae. Curr Genet 36, 317-328.
[52]	Rentsch D, Hirner B, Schmelzer E, Frommer WB (1996). Salt stress-induced proline transporters and salt stress- repressed broad specificity amino acid permeases identified by suppression of a yeast amino acid permease- targeting mutant.Plant Cell 8, 1437-1446. DOI URL PMID
[53]	Rentsch D, Schmidt S, Tegeder M (2007). Transporters for uptake and allocation of organic nitrogen compounds in plants.FEBS Lett 581, 2281-2289. DOI URL PMID
[54]	Sanders A, Collier R, Trethewy A, Gould G, Sieker R, Tegeder M (2009). AAP1 regulates import of amino acids into developing Arabidopsis embryos.Plant J 59, 540-552. DOI URL PMID
[55]	Santiago JP, Tegeder M (2016). Connecting source with sink: the role of Arabidopsis AAP8 in phloem loading of amino acids.Plant Physiol 171, 508-521. DOI URL PMID
[56]	Savouré A, Jaoua S, Hua XJ, Ardiles W, Van Montagu M, Verbruggen N (1995). Isolation, characterization, and chromosomal location of a gene encoding the Δ1-pyrroline- 5-carboxylate synthetase in Arabidopsis thaliana. FEBS Lett 372, 13-19.
[57]	Schmidt R, Stransky H, Koch W (2007). The amino acid permease AAP8 is important for early seed development in Arabidopsis thaliana. Planta 226, 805-813.
[58]	Schwacke R, Grallath S, Breitkreuz KE, Stransky E, Stransky H, Frommer WB, Rentsch D (1999). LeProT1, a transporter for proline, glycine betaine, and γ-amino butyric acid in tomato pollen.Plant Cell 11, 377-391. DOI URL PMID
[59]	Su YH, Frommer WB, Ludewig U (2004). Molecular and functional characterization of a family of amino acid transporters from Arabidopsis.Plant Physiol 136, 3104-3113. DOI URL PMID
[60]	Suzuki A, Mochizuki T, Uemura S, Hiraki T, Abe F (2013). Pressure-induced endocytic degradation of the Saccha- romyces cerevisiae low-affinity Tryptophan Permease Tat1 is mediated by Rsp5 ubiquitin ligase and functionally red- undant PPxY motif proteins. Eukaryot Cell 12, 990-997. DOI URL PMID
[61]	Svennerstam H, Ganeteg U, Näsholm T (2008). Root uptake of cationic amino acids by Arabidopsis depends on functional expression of amino acid permease 5.New Phytol 180, 620-630. DOI URL PMID
[62]	Szabados L, Savouré A (2010). Proline: a multifunctional amino acid.Trends Plant Sci 15, 89-97. DOI URL PMID
[63]	Tan QM, Grennan AK, Pélissier HC, Rentsch D, Tegeder M (2008). Characterization and expression of French bean amino acid transporter PvAAP1. Plant Sci 174, 348-356. DOI URL
[64]	Tanner JJ (2008). Structural biology of proline catabolism.Amino Acids 35, 719-730. DOI URL PMID
[65]	Tilsner J, Kassner N, Struck C, Lohaus G (2005). Amino acid contents and transport in oilseed rape (Brassica na- pus L.) under different nitrogen conditions. Planta 221, 328-338. DOI URL PMID
[66]	Tuskan GA, DiFazio S, Jansson S, Bohlmann J, Grigoriev I, Hellsten U, Putnam N, Ralph S, Rombauts S, Salamov A, Schein J, Sterck L, Aerts A, Bhalerao RR, Bhalerao RP, Blaudez D, Boerjan W, Brun A, Brunner A, Busov V, Campbell M, Carlson J, Chalot M, Chapman J, Chen GL, Cooper D, Coutinho PM, Couturier J, Covert S, Cronk Q, Cunningham R, Davis J, Degroeve S, Déjardin A, Depamphilis C, Detter J, Dirks B, Dubchak I, Duplessis S, Ehlting J, Ellis B, Gendler K, Goodstein D, Gribskov M, Grimwood J, Groover A, Gunter L, Hamberger B, Heinze B, Helariutta Y, Henrissat B, Holligan D, Holt R, Huang W, Islam-Faridi N, Jones S, Jones-Rhoades M, Jorgensen R, Joshi C, Kangasjärvi J, Karlsson J, Kelleher C, Kirkpatrick R, Kirst M, Kohler A, Kalluri U, Larimer F, Leebens-Mack J, Leplé JC, Locascio P, Lou Y, Lucas S, Martin F, Montanini B, Napoli C, Nelson DR, Nelson C, Nieminen K, Nilsson O, Pereda V, Peter G, Philippe R, Pilate G, Poliakov A, Razumovskaya J, Richardson P, Rinaldi C, Ritland K, Rouzé P, Ryaboy D, Schmutz J, Schrader J, Segerman B, Shin H, Siddiqui A, Sterky F, Terry A, Tsai CJ, Uberbacher E, Unneberg P, Vahala J, Wall K, Wessler S, Yang G, Yin T, Douglas C, Marra M, Sandberg G, Van de Peer Y, Rokhsar D (2006). The genome of black cottonwood,Populus trichocarpa(Torr. & Gray). Science 313, 1596-1604.
[67]	Ueda A, Shi WM, Sanmiya K, Shono M, Takabe T (2001). Functional analysis of salt-inducible proline transporter of barley roots.Plant Cell Physiol 42, 1282-1289. DOI URL PMID
[68]	Ueda A, Shi WM, Shimada T, Miyake H, Takabe T (2008). Altered expression of barley proline transporter causes different growth responses in Arabidopsis.Planta 227, 277-286. DOI URL PMID
[69]	Verbruggen N, Hermans C (2008). Proline accumulation in plants: a review.Amino Acids 35, 753-759. DOI URL PMID
[70]	Verbruggen N, Hua XJ, May M, Van Montagu M (1996). Environmental and developmental signals modulate pro- line homeostasis: evidence for a negative transcriptional regulator.Proc Natl Acad Sci USA 93, 8787-8791. DOI URL PMID
[71]	Verslues PE, Sharp RE (1999) Proline accumulation in maize (Zea mays L.) primary roots at low water potentials. II. Metabolic source of increased proline deposition in the elongation zone. Plant Physiol 119, 1349-1360.
[72]	Waditee R, Hibino T, Tanaka Y, Nakamura T, Incharoens akdi A, Hayakawa S, Suzuki S, Futsuhara Y, Kawam itsu Y, Takabe T, Takabe T (2002). Functional charac- terization of betaine/proline transporters in betaine-accu- mulating mangrove.J Biol Chem 277, 18373-18382. DOI URL PMID
[73]	Wood JM (2006). Osmosensing by bacteria.Sci STKE 2006, pe43.
[74]	Wood JM, Bremer E, Csonka LN, Kraemer R, Poolman B, van der Heide T, Smith LT (2001). Osmosensing and osmoregulatory compatible solute accumulation by bac- teria.Comp Biochem Physiol A: Mol Integr Physiol 130, 437-460. DOI URL PMID
[75]	Zhang LZ, Garneau MG, Majumdar R, Grant J, Tegeder M (2015). Improvement of pea biomass and seed productivity by simultaneous increase of phloem and embryo loading with amino acids.Plant J 81, 134-146. DOI URL PMID
[76]	Zhang LZ, Tan QM, Lee R, Trethewy A, Lee YH, Tegeder M (2010). Altered xylem-phloem transfer of amino acids affects metabolism and leads to increased seed yield and oil content in Arabidopsis.Plant Cell 22, 3603-3620. DOI URL PMID
[77]	Zhang R, Zhu J, Cao HZ, Xie XL, Huang JJ, Chen XH, Luo ZY (2013). Isolation and characterization of LHT-type plant amino acid transporter gene from Panax ginseng Meyer. J Ginseng Res 37, 361-370. DOI URL PMID
[78]	Zhao HM, Ma HL, Yu L, Wang X, Zhao J (2012). Genome- wide survey and expression analysis of amino acid trans- porter gene family in rice (Oryza sativa L.). PLoS One 7, e49210. DOI URL PMID
[79]	Zhou YZ, Zhu WD, Bellur PS, Rewinkel D, Becker DF (2008). Direct linking of metabolism and gene expression in the proline utilization A protein from Escherichia coli. Amino Acids 35, 711-718. DOI URL PMID

氨基酸转运蛋白	基因表达位置	对脯氨酸的亲和力	参考文献
AtAAP1	根, 主茎, 花, 胚	60 μmol·L^-1	Lee and Tegeder, 2004; Sanders et al., 2009; Perchlik et al., 2014
AtAAP2	韧皮部	(140±20) μmol·L^-1	Okumoto et al., 2002
AtAAP3	根	(250±25) μmol·L^-1	Okumoto et al., 2004; Svennerstam et al., 2008
AtAAP5	根	(500±25) μmol·L^-1	Okumoto et al., 2004; Svennerstam et al., 2008
AtAAP6	根, 库叶, 茎叶	(67±21) μmol·L^-1	Hunt et al., 2010
AtAAP8	花蕾, 角果	-	Okumoto et al., 2002; Schmidt et al., 2007
AtLHT1	根, 花, 叶	(10±0.5) μmol·L^-1	Hirner et al., 2006
AtLHT2	花	(13±3) μmol·L^-1	Lee and Tegeder, 2004
AtProT1	根, 茎, 花	(427±17) μmol·L^-1	Rentsch et al., 1996; Grallath et al., 2005
AtProT2	根	(500±5) μmol·L^-1	Grallath et al., 2005
AtProT3	叶, 花和角果	(999±36) μmol·L^-1	Grallath et al., 2005

氨基酸转运蛋白	基因表达位置	对脯氨酸的亲和力	参考文献
AtAAP1	根, 主茎, 花, 胚	60 μmol·L^-1	Lee and Tegeder, 2004; Sanders et al., 2009; Perchlik et al., 2014
AtAAP2	韧皮部	(140±20) μmol·L^-1	Okumoto et al., 2002
AtAAP3	根	(250±25) μmol·L^-1	Okumoto et al., 2004; Svennerstam et al., 2008
AtAAP5	根	(500±25) μmol·L^-1	Okumoto et al., 2004; Svennerstam et al., 2008
AtAAP6	根, 库叶, 茎叶	(67±21) μmol·L^-1	Hunt et al., 2010
AtAAP8	花蕾, 角果	-	Okumoto et al., 2002; Schmidt et al., 2007
AtLHT1	根, 花, 叶	(10±0.5) μmol·L^-1	Hirner et al., 2006
AtLHT2	花	(13±3) μmol·L^-1	Lee and Tegeder, 2004
AtProT1	根, 茎, 花	(427±17) μmol·L^-1	Rentsch et al., 1996; Grallath et al., 2005
AtProT2	根	(500±5) μmol·L^-1	Grallath et al., 2005
AtProT3	叶, 花和角果	(999±36) μmol·L^-1	Grallath et al., 2005