• 作者： 廖成康; 盧虎生; 朱鈞
• 作者服務機構： 國立臺灣大學農藝學系
• 中文摘要： 為探討內生植物荷爾蒙ABA在M. crystallinum植物由C3型光合作用轉變為CAM型時的生理角色，本實驗發展出一ABA的抽取純化及indirect-ELISA檢測方法，並利用此方法，測定M. crystallinum植株在NaCl及PEG處理下光合作用由C3轉為CAM型生理過程中，葉片內ABA之變化。 ABA的抽取及純化試驗顯示，葉片樣品必需經過PVP與C18管柱的純化步驟，才不會對後續的indirect-ELISA產生干擾作用。在ABA純化的回收率上，經PVP步驟之回收率為85％，經過PVP與C18管柱之回收率為77％，經過PVP、C18管柱再經HPLC步驟之回收率為71％。PVP管柱純化過程是最主要影響回收率的步驟；本試驗中的平均回收率為70％。放射性ABA追終試驗也發現ABA回收率在樣品之間存在相當的變異，顯示各個樣品於ABA純化步驟中皆需加入放射性ABA以計算回收率。又本實驗之Indirect-ELISA方法中，ABA標準曲線濃度範圍為0.05至5 pmole。 ABA之濃度測定結果顯示，以外加NaCl處理M. crystallinum植株8小時後，其葉片內ABA濃度顯著迅速上升；PEG處理植株24小時後，葉片內ABA濃度也顯著上升，因此處理中之離子濃度及水份潛勢皆可以調節M. crystalli-num葉內ABA之含量。此二種處理引起之葉內ABA濃度增加的時序皆出現於葉內PEP Carboxylase活性上升之前，此結果顯示，葉部內生ABA的變化確實可能參與M. crystallinum由C3型光合作用轉變為CAM型時的生理過程。
• 英文摘要： An indirect ELISA assay for 2-cis(+)abscisic acid (ABA) was developed and applied to determinethe ABA in leaf extracts of Mesembryanthemum crystallinum in response to NaCl and polyethylene glycol(PEG) treatments. In searching for the optimum procedure for ABA purification and ELISA assay, radio-tracer recovery and parallelism tests of extract dilutions for interference were conducted. ABA recoveryduring purification were about 85%, 77% and 71% through polyvinylpyrrolidone (PVP) column, PVPplus a C18 cartridge and PVP plus a C18 cartridge plus reversed-phase high performance liquid chromato-graphy (HPLC), respectively. Average recovery of the whole procedure was about 70%. Elution of PVPcolumn was the major step accounting for ABA lost during purification. Parallelism tests of interferencerevealed that purification with a PVP column following by a C18 cartridge and HPLC was essential tocleanup the interference in leaf extracts for ELISA. In indirect ABA ELISA, the assay was linear from0.05 to 5 pmole of ABA. The developed indirect ELISA was used successfully to estimate the ABA levelsin leaves of Mesembryanthemum crystallinum treated with NaCl and PEG. Significant increases of endo-genous ABA concentration were induced by NaCl and PEG after 8 and 24 h of treatment, respectively.Increases of internal ABA concentrations were temporally earlier than the increase of PEP carboxylaseactivity. The effects of NaCl and PEG on ABA accumulation imply that both salt ion excess and waterstress could regulate the internal ABA level. Current results also suggest that ABA is involved in the facul-tative processes of physiological transition from C3 to CAM in Mesembryanthemum crystallinum.
• 中文關鍵字： abscisic acid; CAM; Mesembryanthemum crystallinum.
• 英文關鍵字： --