Flowers, Timothy J.

Wang, Suomin

Zhang, Jinlin

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Na+ Uptake Pathways in the Halophyte Suaeda maritime Suomin Wang Lanzhou University, China Jinlin Zhang Lanzhou University, China Timothy J. Flowers University of Sussex, UK Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/2-2/45 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 瞯 ]390　 瞯 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　Grasslands/Rangelands Resources and Ecology ——— Soil Quality and Plant NutritionNa＋ uptake pathways in the halophyte SuaedamaritimeSuoMin Wang１ , JinLin Zhang１ , Timothy J . Flowers２１ School o f Pastoral A griculture Science and Technology , L anz hou University , L anz hou ７３００００ ,China , E‐mail : smwang＠lz u .edu .cn , ２ Department o f Biology and Env ironmental Science , School o f L i f e Sciences , University o f Sussex , Falmer ,Brighton , Sussex BN１ ９QG , UKKey words : Halophyte , Na ＋ net uptake , ２２ Na＋ influx , Na＋ uptake pathwaysIntroduction Reducing Na ＋ influx must be the key step for controlling Na ＋ accumulation compared with vacuolar Na ＋compartmentalization and Na＋ extrusion ( Apse et al . , １９９９ ; Ma et al . , ２００４ ;Martínez‐Atienza et al . , ２００７ ) , neither ofwhich would be sufficient alone . However , the pathways by which plants take up Na＋ are uncertain since Na＋ uptake by plantroots has largely been explored using species that accumulate little Na ＋ into their leaves . By way of contrast , the halophyteSuaeda maritima accumulates , without injury , concentrations of the order of ４００ mM NaCl in its leaves . Here we use S .maritima to examine Na＋ uptake pathways .Materials and methods Twenty one to ２３ day old seedlings were used to evaluate the effects of inhibitors of ion transport ongrow th and ion accumulation . Na ＋ analysis was performed using an atomic absorption spectrophotometer . ２２ Na＋ influx wasevaluated according to the method described by Essah et al . ( ２００３) .Results TEA ＋ , Cs ＋ and Ba２ ＋ significantly reduced the net uptake of Na ＋ from １５０ mM NaCl over ４８ h , by ５４％ , ２４％ and２９％ , respectively ( Tables １ and ２ ) . TEA ＋ , Cs ＋ and Ba２ ＋ also significantly reduced ２２ Na＋ influx by ４７％ , ３０％ and ３１％ ,respectively ( Figure １) . In contrast to the situation in １５０ mM NaCl , neither TEA ＋ nor Cs ＋ significantly reduced net Na ＋uptake or ２２ Na＋ influx in ２５ mM NaCl ( Table １ , Figure １ ) . Ba２ ＋ did significantly decrease net Na＋ uptake ( by ４７％ ) and２２ Na＋ influx ( by ３６％ with １ mM Ba２ ＋ ) in ２５ mM NaCl ( Table ２ , Figure １) .　 　 Figure 1 Root 22 Na＋ in f lux o f S .maritima seedlings treated w ithdi f f erent inhibitors .Conclusions We propose that two distinct low‐affinity Na＋ uptake pathways existin S . maritima : Pathway １ is insensitive to TEA ＋ or Cs ＋ , but sensitive to Ba２ ＋and mediates Na＋ uptake in low salinities (２５ mM NaCl) ; Pathway ２ is sensitiveto TEA ＋ , Cs ＋ and Ba２ ＋ and mediates Na ＋ uptakein higher external saltconcentrations (１５０mM NaCl) .Table 1 E f f ect o f TEA ＋ and Cs ＋ on net Na＋ f lux (μmol g‐1 f resh weight rootmin‐1 ) o f S . maritima .NaCl concentration ( mM ) InhitionNone( control) TEA‐ ( １０mM) Cs‐ (３mM)１５０ n０ 缮.５６ ± ０ .０４a ０ 侣.２６ ± ０ .０３c ０ .４３ ± ０ .０３b２５ \０ 缮.２０ ± ０ .０２a ０ 亮.１５ ± ０ .０１a ０ 排.１８ ± ０ .０３aTable 2 E f f ect o f Ba2 ＋ on whole p lant Na＋ content (μmol / p lant) and root netNa＋ f lux (μmol g‐1 f resh weight root min‐1 ) o f S . maritima .BT ２５Na ２５NaBa １５０Na １５０NaBaNa＋ coment ７ 枛.０ ± ０ .５６d ５０ ± ５ ).６１b ２２ ± １ q.４c １００ ± ７ 葺.７a ５１ ± ４ 镲.４bNa＋ netflux ０ 櫃.１９ ± ０ .０２c ０ 後.１０ ± ０ .０１d ０ ).４３ ± ０ .０２a ０ _.３１ ± ０ .０３bAcknowledgements This work was supported by National Natural Science Foundation of China ( ３０６７１４８８ , ３０７００５６２ ,３０７７０３４７) , National High‐Tech Project of China (�８６３"Project ) ( ２００６AA１０Z１２６ ) , National Key Basic Research Project ofChina(�９７３"project) (２００７CB１０８９０１ ) and New Century Talent Supporting Project of China( NCET‐０５‐０８８２) .ReferenceEssah PA , Davenport R , Tester M (２００３) Sodium influx and accumulation in A rabidopsis . Plant Physiology １３３ : ３０７‐３１８ .A 1 C E 0.8 ! -'? a 0.6 □25mM 5. 0.4 '§' 0.2 ~+ z 0 0 5 7.5 10 TEA+concentration(mM) B C a E ~ 0.8 LL -'? 0.6 a 0.4 t 02 .. z 0 05 15 3 10 Cs+concentration(mM) C C a E 0.8 ~ LL 0.6 b -'? □ 25mM a 0.4 □ 150mM t mm C 0.2 z 0 1 10 Ba2+concentration(mM) 

Na\u3csup\u3e+\u3c/sup\u3e Uptake Pathways in the Halophyte \u3cem\u3eSuaeda maritime\u3c/em\u3e

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=2557&amp;context=igc

Na\u3csup\u3e+\u3c/sup\u3e Uptake Pathways in the Halophyte \u3cem\u3eSuaeda maritime\u3c/em\u3e

Abstract

Similar works

Full text

Available Versions

University of Kentucky