Chinese Bulletin of Botany ›› 2020, Vol. 55 ›› Issue (1): 21-30.DOI: 10.11983/CBB19024

• EXPERIMENTAL COMMUNICATIONS • Previous Articles     Next Articles

Effect of Exogenous Substances on Cold Tolerance and Key Sucrose Metabolic Gene Expression in Camellia sinensis

Xiaoqing Yang1,Xiaoqin Huang1,*(),Xiaoyang Han1,Tengfei Liu2,Xiaowei Yue1,Ran Yi1   

  1. 1College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an 271018, China
    2Shandong Institute of Pomology, Tai’an 271018, China
  • Received:2019-02-13 Accepted:2019-05-07 Online:2020-01-01 Published:2019-12-20
  • Contact: Xiaoqin Huang

Abstract:

In recent years, low temperature damage in winter and spring has become an important factor affecting tea production. We used tea tree (Camellia sinensis) potted seedlings to test the effect of GABA, chlorella powder and bamboo vinegar on sucrose-related gene expression (SPS, SUS4, INV4, INV5) and cold-tolerant related physiological indexes. Different concentrations of the three kinds of exogenous substances were sprayed on seedlings under cold stress. We analyzed the expression of SPS, SUS4, INV4 and INV5 of the key sucrose-coding genes as well as the physiological indexes related to cold tolerance to determine the possible physiological and molecular mechanisms of the effect of exogenous substance spraying on cold tolerance of tea trees. The frost index and relative conductivity were significantly lower after application of GABA, chlorella powder or bamboo vinegar than control values and the soluble sugar content was increased. The optimal application concentration for GABA, chlorella powder and bamboo vinegar was 10 mmol·L -1, 0.22 mg·mL -1 and 2.5 mg·mL -1, respectively. Malondialdehyde content was significantly decreased and antioxidant enzyme activity was increased; chlorophyll, soluble sugar and proline content was also increased. Sucrose content was increased by 15.24%, 11.39% and 5.97%, respectively, after 72 h treatment. The expression of SPS, SUS4, INV4 and INV5 in leaves was significantly increased with 10 mmol·L -1 GABA, 0.22 mg·mL -1 chlorella powder and 2.5 mg·mL -1 bamboo vinegar. Thus, GABA, chlorophyll powder and bamboo vinegar can significantly improve the cold tolerance of tea plants. We provide a theoretical basis for the cryoprotectant selection for tea plants.

Key words: tea tree, low temperature stress, soluble sugar, sucrose, cryoprotectant