Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (9): 2435-2442.DOI: 10.3969/j.issn.1000-2561.2021.09.001

• Omics & Biotechnology •     Next Articles

Expression and Function of an ACC Oxidase Gene (HbACO7) from the Bark of Hevea brasiliensis

WANG Yiwei1, FENG Renjun1,2, HUANG Yacheng1, LIU Xiaodong1, FANG Yongjun3, LUO Hongli1, TANG Chaorong1,*()   

  1. 1. Natural Rubber Cooperative Innovation Center, Hainan Province & Ministry of Education of PRC / College of Tropical Crops, Hainan University, Haikou, Hainan 570228, China
    2. Hainan Key Laboratory of Tropical Brain Research and Transformation, Hainan Medical College, Haikou, Hainan 571199, China
    3. Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
  • Received:2020-11-16 Revised:2021-02-23 Online:2021-09-25 Published:2021-11-01
  • Contact: TANG Chaorong

Abstract:

Natural rubber is an important industrial raw material, mainly harvested from the rubber-producing laticifers residing in the bark of rubber tree (Hevea brasiliensis). Previous studies reveal that ethylene promotes both latex flow and regeneration, and the application of ethrel (an ethylene generator) or ethylene on bark could stimulate latex yield. In this study, based on the Hevea genome and transcriptome database we previously constructed, eight HbACO genes encoding the Hevea ACC oxidase (ACO), a key enzyme in ethylene biosynthesis, were cloned and examined for their expression patterns in seven Hevea tissues. Although the HbACO genes exhibited varying degrees of redundant expression in the seven tissues examined, each retained a distinct pattern of tissue expression. Of the eight HbACOs, HbACO7 showed the highest expression in the bark. The expressions of HbACO7 fluctuated greatly with the change of tapping months, showing the highest level in August. The prokaryotic expression vector HbACO7 was successfully constructed, and the expression of HbACO7 protein was induced in E. coli BL21. The purified HbACO7 recombinant protein successfully catalyzed ethylene synthesis in vitro, indicating its functionality as an active ACO enzyme. This study would lay a foundation for further research on the regulatory mechanism of ethylene biosynthesis in the bark of rubber tree.

Key words: Hevea brasiliensis, ethylene, biosynthesis, HbACO7, enzyme activity

CLC Number: