一、简介：

赵天永，教授，博士生导师。本科毕业于河北农业大学园艺系。中国农业大学生物学院硕博连读并获作物遗传育种专业博士学位。曾在美国U.C.Berkeley和University of Kentucky从事博士后研究并随后任职Scientist I、Scientist II。目前承担本科生《分子生物学》英文教学工作以及博士生的《生命科学研究进展》课程。

二、研究方向：玉米抗逆分子生物学

棉子糖是由半乳糖、果糖和葡萄糖结合而成的一种三糖。棉子糖在植物叶片受到逆境胁迫时，或在种子成熟脱水过程中迅速积累，在植物抗逆、种子活力建成中发挥重要作用。由于受到研究材料和研究方法的限制，棉子糖调控植物抗逆和种子活力的作用机制长期未能确定。棉子糖的合成需要两步酶促反应来完成。首先肌醇和UDP-半乳糖苷在肌醇半乳糖苷合成酶（Galactinol Synthase，GOLS）作用下形成肌醇半乳糖苷，然后肌醇半乳糖苷和蔗糖在棉子糖合成酶（Raffinose Synthase，RS）作用下形成棉子糖。

图1 棉子糖代谢调控及其功能

他人和我们的研究表明，过量表达GOLS基因能够提高肌醇半乳糖苷和棉子糖的含量，提高植物的抗逆性。但关于GOLS基因响应逆境的转录调控知之甚少。我们发现了ZmGOLS2基因响应逆境胁迫（Zhao, 2003, 2004）,鉴定了玉米ZmGOLS2基因启动子上响应热激、脱水等元件(Gu, 2013)，并鉴定了在逆境条件下与相关元件结合调控该基因表达的转录因子，发现过量表达ZmGOLS2基因能够提高植物的抗逆性且对植物的生长没有负作用(Gu, 2016, 2019; Zhang, 2019)。关于植物RS基因的研究报道很少，我们实验室最近克隆到了玉米基因组中唯一一个棉子糖合成酶基因（ZmRS），发现玉米ZmRS基因的表达对种子耐老化、植株抗逆起着重要作用 (Li, 2017， 2020)。 此外我们发现转录因子ZmDREB1A直接调控ZmRS基因的表达，在冷胁迫条件下促进棉子糖的合成，提高植物的抗寒性（Han, 2020）。

α-碱性半乳糖苷酶（AGA）是一类能够识别棉子糖中的α-半乳糖苷键，将棉子糖分解为蔗糖与半乳糖的糖苷水解酶（图1）。我们克隆了玉米AGA基因家族的4个成员，发现 ZmAGA1在种子萌发过程中受高温、低温或脱水胁迫和ABA诱导表达(Zhao, 2006； Han, 2015)。AGA基因受逆境胁迫诱导表达的生物学意义尚不清楚。

我们最近发现在玉米不同自交系种子中棉子糖含量存在显著差异，各自交系控制棉子糖合成和水解的关键酶基因的转录水平，翻译水平，以及所编码蛋白的酶催化活性都存在显著差异。我们正在对相关基因的转录调控，翻译调控，酶活调控进行研究。

三、在玉米棉子糖调控种子活力与抗逆领域发表的论文 （第一或通讯作者论文）

1. Qinghui Han, Kelu Chen, Dong Yan, Guanglong Hao, Junlong Qi, Chunmei Wang, Lynnette M. Dirk, A. Bruce Downie, Jianhua Gong, Jianhua Wang, Tianyong Zhao*, 2020, ZmDREB2A regulates ZmGH3.2 and ZmRAFS, shifting metabolism towards seed aging tolerance over seedling growth. The Plant Journal. https://onlinelibrary.wiley.com/doi/10. 1111/tpj.14922.

2. Tao Li, Yumin Zhang, Ying Liu, Xudong Li, Guanglong Hao, Qinghui Han, Lynnette M. Dirk, A Bruce Downie, Yong-Ling Ruan, Jianmin Wang, Guoying Wang, Tianyong Zhao*, 2020, Raffinose synthase enhances drought tolerance through raffinose synthesis or galactinol hydrolysis in maize and Arabidopsis plants. Journal of Biological Chemistry. 2020, 295:8064-8077.

3. Qinghui Han, Junlong Qi, Guanglong Hao, Chunxia Zhang, Chunmei Wang, Lynnette M. Dirk, A Bruce Downie, Tianyong Zhao*, 2020, ZmDREB1A regulates RAFFINOSE SYNTHASE controlling raffinose accumulation and plant chilling stress tolerance in maize. Plant and Cell Physiology. 61: 331-341.

4. Lei Gu, Tao Jiang, Chunxia Zhang, Xudong Li, Chunmei Wang, Yumin Zhang, Tao Li, Lynnette Dirk, Bruce Downie, Tianyong Zhao*, 2019, Maize HSFA2 and HSBP2 antagonistically modulate raffinose biosynthesis and heat tolerance in Arabidopsis. The Plant Journal.  100:128-142.

5. Yumin Zhang, Qichao, Sun, Guanglong Hao, Chunmei Wang, Lynnette, Dirk, Bruce Downie, Tianyong Zhao*, 2019, Maize VIVIPAROUS1 Interacts with ABA INSENSITIVE5 to Regulate GALACTINOL SYNTHASE2 Expression Controlling Seed Raffinose Accumulation. J Agric Food Chem. 67(15): 4214-4223.

6. Tao Li, Yumin Zhang, Dong Wang, Ying Liu, Lynnette Dirk, Jack Goodman, Bruce Downie, Jianmin Wang, Guoying Wang, Tianyong Zhao*, 2017, Regulation of seed vigor by manipulation of raffinose family oligosaccharides (RFOs) in maize and Arabidopsis. Molecular Plant. 10(12): 1540-1555.

7. Lei Gu, Yumin Zhang, Mingshuai Zhang, Tao Li, Lynnette M.A. Dirk, Bruce Downie, Tianyong Zhao*, 2016, ZmGOLS2, a target of transcription factor ZmDREB2A, offers similar protection against abiotic stress as ZmDREB2A. Plant Molecular Biology. 90:157-170hesis or galactinol hydrolysis in maize and Arabidopsis plants. Journal of Biological Chemistry. 2020, 295:8064-8077.

8. Qinghui Han, Tao Li, Lifeng Zhang, Lynnette M.A. Dirk, Bruce Downie, Tianyong Zhao*, 2015, Functional analysis of the 5’ regulatory region of the maize ALKALINE ALPHA-GALACTOSIDASE1 gene. Plant Molecular Biology Reporter. 33:1361-1370.

9. Lei Gu, Zhaoxue Han, Lifeng Zhang, Bruce Downie, Tianyong Zhao*, 2013, Functional analysis of the 5’ regulatory region of the maize GALACTINOL SYNTHASE2 gene, Plant Science 213：38-45.

10. Tianyong Zhao, J. Willis Corum III, Jeffrey Mullen, Robert B. Meeley, Timothy Helentjaris, David Martin, and Bruce Downie, 2006, An alkaline a-galactosidase transcript is present in maize seeds and cultured embryo cells, and accumulates during stress. Seed Science Research. 16:107-121.

11. Tianyong Zhao, Richard Thacker, J. Willis Corum III, John C. Snyder, Robert B. Meeley, Ralph Obendorf, and Bruce Downie, 2004, Expression of the maize GALACTINOL SYNTHASE gene family. I) Expression of two different genes during seed development and germination. Physiol. Plant. 121(4):634-646.

12. Tianyong Zhao, David Martin, Robert B. Meeley, and Bruce Downie, 2004, Expression of the maize GALACTINOL SYNTHASE gene family. II) Kernel abscission, environmental stress and myo-inositol influences accumulation of transcript in developing seeds and callus cells. Physiol. Plant .121 (4): 647-655.

13. Tianyong Zhao, Robert Meeley, and Bruce Downie, 2003, Aberrant processing of a Maize GALACTINOL SYNTHASE transcript is caused by heat stress. Plant Science. 165:245-256.

四、主持课题

1. 国家自然基金

2. 国家科技公关重大专项重点项目

3. 陕西省自然基金

联系方式：tzhao2@nwsuaf.edu.cn