title: Aluminum regulates oxalate secretion and plasma membrane H+-ATPase activity independently in tomato roots.
abstract: We demonstrated that aluminum (Al)-induced oxalate secretion and plasma membrane (PM) H(+)-ATPase activity in tomato (Lycopersicon esculentum 'Hezuo903') roots were poorly correlated. In addition, vanadate, an inhibitor of PM H(+)-ATPase, had no effect on Al-induced oxalate secretion, but significantly inhibited enzyme activity. An anion channel inhibitor phenylglyoxal inhibited oxalate secretion, but not PM H(+)-ATPase activity. Exposure of tomato roots to 10 μM LaCl(3) also stimulated PM H(+)-ATPase activity; however, La failed to induce oxalate secretion. Furthermore, Al-induced changes of PM H(+)-ATPase activity were not associated with oxalate secretion in two tomato cultivars differing in the ability to secrete oxalate under Al stress. These results indicate that Al independently regulates oxalate secretion and PM H(+)-ATPase activity in tomato roots. Analysis of expression levels of PM H(+)-ATPase genes by real-time reverse transcription-PCR and protein by Western blot and immunodetection revealed that the regulation of PM H(+)-ATPase in response to Al was subjected to transcriptional and posttranscriptional control. However, since neither transcriptional level of genes nor translational level of proteins directly relate to the enzyme activity, posttranslational modification of PM H(+)-ATPase under Al stress likely contributes to changes in activity of this protein.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China. yangjianli@zju.edu.cn
authors.forename: Jian Li
authors.initials: JL
authors.lastname: Yang
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Zhu
authors.forename: You Xiang
authors.initials: YX
authors.lastname: Peng
authors.forename: Cheng
authors.initials: C
authors.lastname: Zheng
authors.forename: Feng
authors.initials: F
authors.lastname: Ming
authors.forename: Shao Jian
authors.initials: SJ
authors.lastname: Zheng
mesh_terms: D000535:Aluminum / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007811:Lanthanum / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D010070:Oxalates / Q000032:analysis / Q000378:metabolism*; D010658:Phenylglyoxal / Q000494:pharmacology; D053147:Plant Exudates / Q000032:analysis / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D014638:Vanadates / Q000494:pharmacology
chemical_list: D010070:Oxalates; D053147:Plant Exudates; C028521:lanthanum chloride; D014638:Vanadates; D007811:Lanthanum; D000535:Aluminum; D006180:Proton-Translocating ATPases; D010658:Phenylglyoxal