| 摘要: | 由於近年來越來越頻繁且越嚴重的乾旱，多年生茶樹 (Camellia sinensis (L.) O. Kuntze) 面臨著產量和品質下降的重大挑戰。應對此威脅的永續性手段之一為開發較為抗旱的新茶樹品種，而了解茶樹反應乾旱壓力的分子機制則對促進新品種的培育至關重要。我的實驗室夥伴黎黃魁元已使用了RNA-seq對臺茶12號、臺茶19號、臺茶22號和青心烏龍四種臺灣茶品種進行了乾旱壓力下的轉錄組反應比對。為了驗證該分析結果，本研究使用RT-qPCR技術偵測在四個茶樹品種正常給水與乾旱壓力下，九個與乾旱耐受差異性可能有相關的基因之表現量差異，此九基因所轉譯出之蛋白質包含參與信號傳遞的蛋白激酶 MPK3、催化製造活性氧化物（ROS）的氧化酶 RBOH、ABC運輸蛋白ABCG21、NAC轉錄因子編碼基因NAC083、MYB轉錄因子編碼基因MYBH/KUA1、參與酚類原生代謝途徑的酶編碼基因C4H、參與木質素生物合成的酵素 HCT 和 F5H、以及參與類黃酮生物合成的酵素F3’H。結果顯示在乾旱壓力下，根據RT-qPCR分析結果，在TTES No. 22中，MPK3和RBOH呈顯著上調。在臺茶12號 和臺茶22號中，ABCG21、NAC083、F3’H、HCT和F5H呈顯著上調。MYBH/KUA1和C4H在四個茶樹品種中未表達差異。RT-qPCR分析的結果與RNA-seq分析的結果基本一致。此研究驗證了茶樹抗旱反應的轉錄組分析結果，並具有輔助較耐旱茶樹育種分子標誌的開發潛能。;The perennial tea plants (Camellia sinensis (L.) O. Kuntze) are imposed by a significant challenge of deteriorating yield and quality due to a more frequent and severe drought in recent years. Understanding the molecular mechanisms of drought stress response in tea plants is important to facilitate new tea cultivar development as one sustainable approach for coping with this threat. Nguyen Hoang Khoi Le, a labmate of mine, has investigated the transcriptomic response to drought stress in four genetically related Taiwan tea cultivars with contrasting drought tolerance (TTES No. 12, TTES No. 19, TTES No. 22, and Chin-Shin-Oolong) by using RNA-seq analysis. In this study, I aimed to confirm the RNA-seq analysis results using the RT-qPCR method. Several genes putatively associating to differential tolerance to drought were tested, including MPK3 which encodes a protein kinase involved in signal transduction, RBOH encodes oxidase to produce reactive oxygen species, ABCG21 encodes ATP-binding cassette transporter, NAC083 encodes the NAC transcription factor, MYBH/KUA1 encodes an MYB transcription factor, C4H encodes an enzyme involved in phenylpropanoid biosynthesis, HCT and F5H encode enzymes involved in lignin biosynthesis, and F3’H encodes an enzyme involved in flavonoid biosynthesis. According to the RT-qPCR analysis, MPK3 and RBOH were significantly up-regulated in TTES No. 22. ABCG21, NAC083, F3’H, HCT, and F5H were significantly up-regulated in TTES No. 12 and TTES No. 22. MYBH/KUA1 and C4H were not differentially expressed in four tea cultivars. The results of RT-qPCR analysis were largely consistent with the result of RNA-seq analysis. These findings would shed light on the molecular mechanism underlying drought resistance in the tea plants, highlighting potential gene targets for drought-tolerant tea cultivars breeding development. |
