OsAKR5基因於逆境處理下水稻培養細胞之暫時性表現

植物中 Aldose reductase（AKR）可能與醣醇生合成、逆境耐受性與細胞解毒作用有關。本研究室最早選殖出5個水稻 OsAKR 基因，在懸浮培養系統發現 OsAKR5 受 ABA 與 Sorbitol 誘導（Lin et al. 2008）。本研究進一步分析水稻不同生育階段與部位 OsAKRs 之表現情形，也將針對受 ABA 與其他逆境誘導之 OsAKR5 基因，釣取其啟動子序列，並接上 β-glucuronidase（GUS）報導基因，以農桿菌轉殖入水稻後，觀察 OsAKR5 基因在不同逆境處理下轉殖細胞系（transgenic cell line; TCL）之表現模式。試驗結果顯示在正常栽培下完整植株中，OsAKR1 與 OsAKR3 主要在葉片中表現，而 OsAKR5 與只有在成熟期穀粒之胚中大量表現。另外，將 OsAKR5 啟動子接上 GUS 進行基因轉殖後，得到10個轉殖細胞系可在篩選培養基中增殖，轉殖效率約為 2％；以不同逆境處理後進行 GUS 染色，結果有8個 TCLs 可觀察到 GUS 呈色，其中有4個 TCLs 可受 4℃ 或 43℃ 溫度處理之誘導，而有6個 TCLs 在鹽分逆境誘導下 GUS 呈色有增強之現象，此外也有2個轉殖系受 sorbitol 誘導。上述結果顯示，已成功獲得轉殖細胞系，且 OsAKR5 基因之啟動子確實受到不同逆境之調控，將進一步進行植株再生獲得完整轉殖株，以觀察在不同部位之表現情形。

關鍵字

水稻；醛醣還原酶；啟動子；暫時性表現；非生物性逆境

並列摘要

Aldose reductase (AKR) may play a role in cellular detoxification, sugar alcohol biosynthesis, and stresses tolerance. In our preliminary study, five isogenes of aldose reductase (OsAKR) from rice were cloned and characterized. The OsAKR5 is strongly induced by ABA and sorbitol treatments (Lin et al. 2008). Here, OsAKR5 was found specifically expressed at embryo of matured grain. The promoter sequence (-1041 bp upstream from ATG) of OsAKR5 gene was isolated and fused with β-glucuronidase (GUS) reporter genes, and then transformed into rice callus by Agrobacterium- mediated method. A total of ten putative transgenic cell lines (TCL) were amplified on selection medium containing 50 mgL^-1 hygromycin. The transgenic efficiency was approximately 2%. GUS staining was further determined after chilling, high temperature, salt, and sorbitol treatments. The GUS staining was enhanced by 4℃ treatment in TCL2, TCL3, TCL8 and TCL9; however, it was induced by 43℃ treatment in TCL3, TCL6 and TCL9. In addition, six and two of 10 TCLs were enhanced by salt and sorbitol treatments, respectively. These results suggest that the promoter of OsAKR5 gene is regulated by multiple abiotic stresses.

並列關鍵字

Oryza sativa ； Aldose reductase ； Promoter ； Transient expression ； Abiotic stress

國際替代計量

OsAKR5基因於逆境處理下水稻培養細胞之暫時性表現

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