NTUBST2019

• 美國密西根州立大學生化系 博士 (1989~1994)
• 國立臺灣大學 農業化學系 碩士 (1987~1989)
• 國立臺灣大學 農業化學系 學士 (1981~1985)

植物高溫逆境反應與耐熱多樣性
本研究室利用分子遺傳學方法，探討植物如何適應及耐受環境高溫的不利因素。高溫逆境減損農作物的產量與品質，在氣候暖化的趨勢下，高溫逆境發生頻率的增加，將嚴重威脅未來糧食安全。改良作物對高溫的適應性是確保糧食安全的一個選項。找出影響植物高溫適應性的主要遺傳因子，則有助於達成此作物改良之目標。

我們以阿拉伯芥及水稻作為研究材料，使用多種學門研究工具，例如，生化、分子生物、植物生理、遺傳、分子演化等，並以生物資訊平台分析基因體及轉錄體資料，探索植物基因在不同高溫環境中所扮演的角色及其作用的機制：

I. 植物熱休克因子(Heat Shock Factor, HSF)家族成員之功能研究－ HSF 是調控熱休克蛋白基因表達的轉錄因子。在高溫、高鹽、滲透壓以及氧化逆境下，阿拉伯芥 HSFA1 亞型的成員負責調控許多熱休克蛋白基因的轉錄，係植物耐受這些不良環境所必需的重要轉錄因子。它們也調控其它轉錄因子的表達，如 HSFA2、HSFB1、DREB2A、bZIP28 等，共同形成複雜的訊息傳導網路。此外，阿拉伯芥 HSFA1 亞型成員及 HSFA2 在功能上發展出專一性，使得不同的 HSF 負責對應不同的環境條件。目前，影響植物 HSF 功能專一性的原因並不清楚，有待實驗進一步釐清。

"HSF 功能研究"

II. 延長熱鍛鍊(heat acclimation)效應的分子調控機制－熱鍛鍊作用透過 HSF 促進熱休克蛋白的生成，例如，負責修復蛋白質摺疊的HSP101，可提高植物對有害高溫的適應性，一般也稱作後天耐熱性(acquired thermotolerance)。當回到正常溫度時，後天耐熱性便逐漸減低至鍛鍊前的程度。我們的研究發現，植物透過至少兩個途徑來延長熱鍛鍊效應：1. HSFA2 參與的轉錄調控途徑；2. HSP101 及 HSA32 蛋白在後轉錄(posttranscription)階段的正回饋調控途徑。

前者透過 HSFA1-HSFA2 的串聯，延長了部份熱休克蛋白基因的轉錄活動，後者則涉及熱休克蛋白間在轉譯合成與降解層面的相互作用，可能的機制為 HSP101 提高了一個陸生植物所特有的熱誘導蛋白HSA32 的生合成，而 HSA32 則回過頭來減緩了 HSP101 的降解，間接地延長熱鍛鍊效應的效期。未來，我們將進一步釐清其分子機制，以及了解對作物高溫適應性的影響。

“延長熱鍛鍊效應之調控機制”

III. 耐熱反應多樣性(thermotolerance diversity)－ 在自然環境中，植物必須面對各種不同的高溫狀態，例如，短暫的極端高溫和長時間的中度高溫，對於植物的影響不同，植物該如何應付呢？透過基因功能的研究，我們發現在阿拉伯芥中至少存在四種不一樣的耐熱反應：基礎耐熱性Basal thermotolerance (BT); 短期後天耐熱性Short-term acquired thermotolerance (SAT); 長期後天耐熱性Long-term acquired thermotolerance (LAT); 耐中溫性 Thermotolerance to moderately high temperature (TMHT)，需要不同的基因參與作用。例如，HSP101 參與了BT、SAT及LAT，但對於TMHT的重要性不大。相反地，一個位於粒線體的熱休克蛋白MGE2則對於TMHT而言是必需的，但對其它三種耐熱反應的影響較微小。對於植物耐熱多樣性的認識，有助於基因功能的探討，以及對植物高溫適應性進一步的理解。未來對於作物的研究應考慮耐熱性狀表型下的複雜性，縮小尋找相關遺傳因子的範圍。

“耐熱反應多樣性”

• 臺大生化科技學系 合聘教授 (2015~now)
• 中央研究院農生中心 研究員 (2015~now)
• 臺大微生物與生化學研究所 合聘副教授 (2006~2015)
• 中央研究院農生中心 副研究員 (2006~2015)
• 中央研究院生農所籌備處 助研究員 (1998~2006)
• 中央研究院植物所 博士後研究 (1995~1997)
• 美國加州大學戴維斯分校蔬菜作物系 博士後研究 (1994~1995)

1. Szaker HM, Darkó É, Medzihradszky A, Janda T, Liu HC, Charng YY, Csorba T (2019) miR824/AGAMOUS-LIKE16 module integrates recurring environmental heat stress changes to fine-tune poststress development. Front Plant Sci 10:1454
2. Liu HC, Lämke J, Lin SY, Hung MJ, Liu KM, Charng YY, Bäurle I (2018) Distinct heat shock factors and chromatin modifications mediate the organ‐autonomous transcriptional memory of heat stress. Plant J 95:401-413
3. Rytz TC, Miller MJ, McLoughlin F, Augustine RC, Marshall RS, Juan YT, Charng YY, Scalf M, Smith LM, Dr. Vierstra RD (2018) SUMOylome profiling in Arabidopsis reveals a diverse array of nuclear targets modified by the sumo ligase SIZ1 during heat stress. Plant Cell 30:1077-1099
4. Lin YP, Charng YY (2017) Supraoptimal activity of CHLOROPHYLL DEPHYTYLASE1 results in an increase in tocopherol level in mature Arabidopsis seeds. Plant Signal Behav e1382797
5. Vicente J, Mendiondo GM, Movahedi M, Peirats-Llobet M, Juan YT, Shen YY, Dambire C, Smart K, Rodriguez PL, Charng YY, Gray JE, Holdsworth MJ (2017) The Cys-Arg/N-End rule pathway is a general sensor of abiotic stress in flowering plants. Curr Biol 27:3183-3190
6. Merret R, Carpenier MC, Favory, JJ, Picart C, Descombin J, Bousquet-Antonelli C, Tillard P, Lejay L, Deragon JM, Charng YY (2017) Heat-shock protein HSP101 affects the release of ribosomal protein mRNAs for recovery after heat shock. Plant Physiol 174:1216-1225
7. Lin YP, Wu MC, Charng YY (2016) Identification of a chlorophyll dephytylase involved in chlorophyll turnover in Arabidopsis. Plant Cell 28:2974-2990
8. Merret R, Nagarajan VK, Carpentier MC, Park S, Favory JJ, Descombin J, Picart C, Charng YY, Green PJ, Deragon JM, Bousquet-Antonelli C (2015) Heat-induced ribosome pausing triggers mRNA co-translational decay in Arabidopsis thaliana. Nucleic Acids Res 3:4121-4132
9. Lin YP, Lee TY, Tanaka A, Charng YY (2014) Analysis of an Arabidopsis heat-sensitive mutant reveals that chlorophyll synthase is involved in reutilization of chlorophyllide during chlorophyll turnover. Plant J 80:14-26
10. Kuo HF, Chang TY, Chiang SF, Wang WD, Charng YY, and Chiou TJ (2014) Arabidopsis inositol pentakisphosphate 2-kinase, AtIPK1, modulates phosphate homeostasis via transcriptional regulation. Plant J 80:503-515
11. Lin MY, Chai KH, Ko SS, Kuang LY, Lur HS, and Charng YY (2014) A positive feedback loop between HSP101 and HSA32 modulates long-term acquired thermotolerance illustrating diverse heat stress responses in rice varieties. Plant Physiol 164:2045-2053
12. Liu HC, Charng YY (2013) Common and distinct functions of Arabidopsis class A1 and A2 heat shock factors in diverse abiotic stress responses and development. Plant Physiol 163:276-290
13. Wu TY, Juan YT, Hsu YH, Wu SH, Liao HT, Fung RWM, Charng YY (2013) Interplay between heat shock proteins, HSP101 and HSA32, prolongs heat acclimation memory posttranscriptionally in Arabidopsis. Plant Physiol 161:2075-2084
14. Merret R, Descombin J, Juan YT, Favory JJ, Marie-Christine Carpentier MC, Cristian Chaparro C, Charng YY, Deragon JM, Bousquet-Antonelli C (2013) XRN4 and LARP1 are required for a heat-triggered mRNA decay pathway involved in plant acclimation and survival during thermal stress. Cell Rep 5:1279-1293
15. Hu C, Lin SY, Chi WT, Charng YY (2012) Recent gene duplication and subfunctionalization produced a mitochondrial GrpE, the nucleotide exchange factor of Hsp70 complex, specialized in thermotolerance to chronic heat stress in Arabidopsis. Plant Physiol 158:747-758
16. Liu HC, Charng YY (2012) Acquired thermotolerance independent of heat shock factor A1 (HsfA1), the master regulator of the heat stress response. Plant Signal Behav 7:547-550
17. Yeh CH, Kaplinsky NJ, Hu C, Charng YY (2012) Some like It hot, some like It warm: phenotyping to explore thermotolerance diversity. Plant Sci 195:10-23 (Review article)
18. Liu HC, Liao HT, Charng YY (2011) The role of class A1 heat shock factors (HSFA1s) in response to heat and other stresses in Arabidopsis. Plant Cell Environ 34:738-751
19. Chi WT, Fung RWM, Liu HC, Hsu CC, Charng YY (2009) Temperature-induced lipocalin is required for basal and acquired thermotolerance in Arabidopsis. Plant Cell Environ 32:917-927
20. Charng YY, Liu HC, Liu NY, Chi WT, Wang CN, Chang SH, Wang TT (2007) A heat-inducible transcription factor, HsfA2, Is required for extension of acquired thermotolerance in Arabidopsis. Plant Physiol 143:251-262
21. Charng YY, Liu HC, Liu NY, Hsu FC, and Ko SS (2006) Arabidopsis Hsa32, a novel heat-shock protein, is essential for acquired thermotolerance during a long recovery period after acclimation treatment. Plant Physiol 140:1297-1305