跳到主要內容

臺灣博碩士論文加值系統

(34.204.169.230) 您好!臺灣時間:2024/03/03 02:08
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

我願授權國圖
: 
twitterline
研究生:劉坤祥
研究生(外文):Liu, Kun-hsiang
論文名稱:低親和性硝酸鹽轉運蛋白CHL1參與高親和性硝鹽吸收之研究
論文名稱(外文):A low-affinity nitrate transporter, CHL1, is also involved in high-affinity nitrate uptake
指導教授:蔡宜芳蔡宜芳引用關係黃啟穎黃啟穎引用關係---
指導教授(外文):Tsay, Yi-fangHuang, Chi-yng
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:植物學系
學門:生命科學學門
學類:生物學類
論文種類:學術論文
論文出版年:1998
畢業學年度:86
語文別:中文
論文頁數:2
中文關鍵詞:硝酸鹽低親和性離子吸收阿拉伯芥轉運蛋白高親和性
外文關鍵詞:nitrateLow-affinityion uptakeArabidopsistransporterHgh-affinity
相關次數:
  • 被引用被引用:1
  • 點閱點閱:399
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
植物對於硝酸鹽的吸收依其親和性及受硝酸鹽誘導與否, 可分為高親和性
誘導型, 高親和性持續型, 低親和性誘導型及低親和性持續型四種硝酸鹽
吸收系統. 一般認為不同的系統是由不同的轉運蛋白來負責執行.
CHL1原本認為是一個低親和性誘導型硝酸鹽轉運蛋白. 本篇論文中針對
CHL1基因缺失植株(chl1-5)及野生株作硝酸鹽吸收分析時,發現chl1-5除
了在低親盒性削酸鹽的吸收有缺失外在高親和性誘導型及持續型削酸鹽吸
收系統上亦出現缺失.
也利用在不同培養基生長後作硝酸鹽吸收測試, 發現這個缺失的現象並非
在不同的培養基生長下造成細胞內pH值不同所引起的.而高親和性吸收的
缺失也進一步由氯酸鹽的抗性實驗獲得確認;野生株在10micromolar得氯
酸鹽處理後會死亡而chl105則可存活下來.
由以下三個實驗證實這缺失是由CHL1所引起的:(一). 在其他五株chl1突
變株作硝酸鹽的吸收實驗中則排除了為其他相連CHL1基因也缺失所造成的
現象.(二). 利用花椰蔡鑲嵌病毒啟動子表現CHL1基因, 並將其轉殖入
chl1-5的植株中, 轉植植株可回復chl1-5在高親和性硝酸鹽的吸收能力.
(三)利用非洲爪蟾將CHL1 mRNA注射入卵中表現作功能試驗證實CHL1是一
個雙親和性的轉運蛋白. 同時參與高親和性與低親和性硝酸鹽的吸收. 此
外, 另一個低親和性持續型硝酸鹽轉運蛋白, NTL1, 則只負責低親和性硝
酸鹽的吸收. 因為以其轉殖反義基因之轉殖植株作硝酸鹽的吸收測試時則
無此高親和性吸收缺失現象;
另外將NTL1表現於非洲爪蟾卵細胞時只測到低親和性吸收的活性. 由此可
見,CHL1可因外在濃度變化而改變其作用模式來負責多項吸收系統(低親和
性誘導型,高親和性誘導型, 及部份的高親和性持續型), 但NTL1只單純地
負責低親和性持續型的吸收.

CHL1 has been reportered to be an inducible low affinity
nitrate transporter. In this thesis, we found that CHL1 was
also involved in high affinity nitrate uptake.
A deletion mutant chl1-5 was demonstrated to be defective
in high affinity nitrate uptake. This observation was uphelpe
by a chlorosis test on wild type and chl1-5 at 10 micromolar
chlorate. The possibility that this phenomenum may be caused by
different cytosolic pH was ruled out because same results were
obtained from plants grown in different nitraogen source. when
another five chl1 mutants were assayed, it showed that the
reduction in high affinity uptake is directly caused by the
defect in CHL1
CHL1 gene. And, a trangenic plant expressing 35 S-CHL1 cDNA in
the deletion background showed a recovery in uptake.
NTL1 is a second nitrate transporter gene of Arabidopsis
which is involved in the constitutive low affinity nitrate
uptake. The high affinity nitrate uptake activity in an anti-
sense mutant of NTL1 is the same as wild type, suggessting
that the dual defect in high and low affinity nitrate uptake
is specific to chl1, but can not be generalized to other
Arabidopsis nitrate transporters.
This observation is further supported by the uptake assay using
HPLC in the hertero-expression system of xenopus oocytes. Both
low annd high affinity uptake activities were observed in CHL1-
injected oocyte In NTL1-injected oocyte, there is only low-
affinity uptake activity. Thus, CHL1 is a dual-affinity
transporter involved in multiple systems (inducible low-
affinity, inducible high-affinity, and some constitutive high-
affinity) of nitrate uptake in Arabidopsis, while NTL1 is a
pure low-affinity transporter
responsible for constitutive low-affinity nitrate uptake.

QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
無相關期刊