赵天永

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。

一、研究方向：玉米抗逆分子生物学

棉子糖是由葡萄糖、果糖和半乳糖聚合而成的三糖，存在于所有植物中。 棉子糖生物合成过程首先由肌醇半乳糖苷合成酶（Galactinol synthase，GOLS）催化肌醇（myo-inositol）与UDP-半乳糖（UDP-galactose）合成肌醇半乳糖苷（Galactinol），之后在棉子糖合成酶（Raffinose synthase，RAFS）作用下将蔗糖和肌醇半乳糖苷合成棉子糖（图1）。

图1 棉子糖合成通路

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(Gu, 2016, 2019; Zhang, 2019)。

我们鉴定了玉米棉子糖合成酶基因（ ZmRAFS ），并发现玉米 ZmRAFS 基因突变体种子胚和胚乳中棉子糖缺失，种子耐老化能力显著降低。我们发现在拟南芥中超表达 ZmGOLS2 或共超表达 ZmGOLS2/ZmRS 基因能改变种子中碳分配，显著提高拟南芥种子活力(Li, 2017)。我们发现在拟南芥中超表达ZmRAFS基因提高了叶片中肌醇含量，增强了拟南芥植株的耐旱性（Li, 2020）,而在玉米中超表达ZmRAFS基因提高了玉米叶片中棉子糖的含量，增强了植株的耐旱性，且对玉米在正常条件下的生长没有副作用（Liu, 2023）。此外，我们发现转录因子ZmDREB2A在调控ZmRAFS基因的表达提高种子耐老化能力的同时，也调控生长素降解酶基因（ZmGH3.2）的表达，抑制植物的生长（Han, 2020）；发现转录因子ZmDREB1A直接调控玉米ZmRAFS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, 2019）。

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。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，在调控种子耐老化过程中发挥重要作用(Zhao, 2006； Han, 2015； Zhang, 2021)。

我们通过生物技术手段获得了耐旱、耐热能力显著 提高的转基因玉米综31自交系，之后通过常规回交转育手段，对我国玉米主栽品种郑单958、先玉335的亲本自交系进行了改良。于2022年春获得了改良郑单958杂交种。改良杂交种幼苗耐旱能力显著高于对照（图2）。

图2. 改良郑单958幼苗耐旱能力显著高于对照

2022年7月上旬杨凌干旱高温（图3），改良郑单958杂交种田间表现明显优于未改良杂交种（图4）。

图3.杨凌天气情况

图4. 改良郑单958植株与对照品种表型比较。

2022年在甘肃景泰进行了产量测定。改良杂交种在灌水、控水、干旱三种条件下产量都高于对照郑单958杂交种（图5）。

图5. 改良郑单958产量高于对照品种。

二、在棉子糖代谢调控玉米耐逆领域发表的论文 （第一或通讯作者论文）

(1)Ying Liu, Tao Li, Chunxia Zhang, Wenli Zhang, Nan Deng, Lynnette M. Dirk, A. Bruce Downie, Tianyong Zhao*, 2023, Raffinose positively regulates maize drought tolerance by reducing leaf transpiration. The Plant Journal. https://onlinelibrary.wiley.com/doi/10.1111/tpj.16116

(2)Yumin Zhang , Dan Li, Lynnette M. Dirk, A. Bruce Downie, Tianyong Zhao*,2021, ZmAGA1 hydrolyzes rfos late during the lag phase of seed germination, shifting sugar metabolism toward seed germination over seed aging tolerance. Journal of Agricultural and Food Chemistry. 69 (39):11606-11615.

(3)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. 104(1): 268-282.

(4)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.

(5)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.

(6)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.

(7)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. Journal of Agricultural and Food Chemistry. 67(15): 4214-4223.

(8)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.

(9)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. 90:157-170

(10)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.

(11)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.

(12)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 .

(13)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.

(14)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.

(15)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.

三、主持课题

1. 国家自然科学基金

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@nwafu.edu.cn （本实验室招聘有作物遗传育种、生化化学、分子生物学背景的博士后，待遇从优）。