• 耕作栽培·生理生化 •

### 高温干旱下油菜的木质化应答及其在茎与根中的差异

1. 重庆市油菜工程技术研究中心 / 重庆市作物品质改良重点实验室 / 南方山地农业教育部工程研究中心 / 西南大学农学与生物科技学院，重庆北碚 400715
• 收稿日期:2017-01-10 修回日期:2017-05-10 出版日期:2017-11-12 网络出版日期:2017-05-19
• 通讯作者: 柴友荣, E-mail: chaiyourong@163.com
• 基金资助:

本研究由教育部高等学校博士学科点专项科研基金项目(20130182110006), 国家重点基础研究发展计划(973计划)项目(2015CB150201), 国家自然科学基金项目(31171177, 31371238), 国家重点研发计划试点专项(2016YFD0100506)和重庆市基础科学与前沿技术研究专项重点项目(cstc2015jcyjBX0143)资助。

### Lignification Response and the Difference between Stem and Root of Brassica napus under Heat and Drought Compound Stress

YIN Neng-Wen**,LI Jia-Na**,LIU Xue,LIAN Jian-Ping,FU Chun,LI Wei,JIANG Jia-Yi,XUE Yu-Fei,WANG Jun,CHAI You-Rong*

1. Lignification Response and the Difference between Stem and Root of Brassica napus under Heat and Drought Compound Stress
• Received:2017-01-10 Revised:2017-05-10 Published:2017-11-12 Published online:2017-05-19
• Contact: 柴友荣, E-mail: chaiyourong@163.com
• Supported by:

This study was supported by the Specialized Research Fund for the Doctoral Program of Higher Education (20130182110006), the National Basic Research Program of China (973 Program, 2015CB150201), National Natural Science Foundation of China (31171177, 31371238), Ministry of Science and Technology of China (2016YFD0100506), and Chongqing Research Program of Basic Research and Frontier Technology (cstc2015jcyjBX0143).

Abstract:

Using histochemical, biochemical, and gas chromatography-mass spectrometry (GC-MS) technologies, the responsive trends of xylem structure and lignin components in the stem and the root of rapeseed (Brassica napus) cultivar Zhongshuang 10 under heat and drought stresses were investigated as compared with normal-growth plants. Histochemical staining of the frozen sections showed that, compared with the cage-grown plants (normal plants), the plants grown in greenhouse (stressed plants) had a thicker xylem part in both stem and root, with deeper staining color. Correspondingly, the total lignin content in the stem of stressed plants tested by acetyl bromide method increased by 31.64% compared with that of the normal plants. Besides, heat and drought compound stress reduced vessel inner diameter in the stem, while increased both vessel number and vessel inner diameter in the root. Stem total lignin monomer yield prepared by thioacidolysis of stressed plants was 40.08% lower than that of the normal plants, indicating higher condensed bonds in stressed plants. Meanwhile, the S/G ratio (1.82) was significantly higher than that of the normal plants (1.29), indicating increased proportion of S units and decreased proportion of G units. Furthermore, this study also revealed the difference of lignification traits between the stem and the root. The stem had lower condensed bonds and major proportion of S units (S/G=1.29), while the root had more condensed bonds and major proportion of G units (S/G=0.49). Moreover, the H unit percentage in the root (7.43%) was almost 10 folds as that in the stem (0.83%). Since H and G units have lower methylation levels and are easier to form condensed bonds, the high proportions of H and G units might be the main reason for the high proportion of condensed bonds in root lignin structure.