Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (10): 2849-2858.DOI: 10.3969/j.issn.1000-2561.2021.10.014

• Omics & Biotechnology • Previous Articles     Next Articles

Enzymatic Activity and Gene Expression of Sucrose-Metabolizing Enzymes in Latex and Bark of Two Hevea Varieties (‘Reyan7-33-97’ and ‘PR107’)

LIU Xiaodong1, WANG Yiwei1, XIAO Xiaohu2, ZHU Fangyu1, LIU Xing1, MO Chunyan1, FANG Yongjun2, TANG Chaorong1,*()   

  1. 1. Natural Rubber Cooperative Innovation Center of Hainan Province & Ministry of Education, China / College of Tropical Crops, Hainan University, Haikou, Hainan 570228, China
    2. Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 571101, China
  • Received:2021-02-08 Revised:2021-03-10 Online:2021-10-25 Published:2021-11-25
  • Contact: TANG Chaorong

Abstract:

In this paper, the activity of sucrose-metabolizing enzymes and expression of relevant genes in two carbon sinks (latex and trunk bark) that are directly involved in rubber production, as well as latex physiological parameters and bark n on-structural carbohydrate (NSC), were investigated in two Hevea varieties (‘Reyan7-33-97’ and ‘PR107’) of different rubber productivity during their peak yielding season. Seasonal dynamic change in dry rubber yield was larger in ‘PR107’ than in ‘Reyan7-33-97’, but both varieties exhibited a peak at late Sept. Latex total solid content, inorganic phosphorus and sucrose were not significantly different between the two varieties, but dry rubber content was significantly higher in ‘Reyan7-33-97’ than in ‘PR107’. Soluble sugar accounted for more than 80% of the NSC in trunk bark, and the differences in NSC and its component sugars (starch, soluble sugar and reducing sugar) were not significant between the two varieties. In the latex, sucrose synthase (Sus) catalyzed the reaction towards sucrose synthesis, and the activity of alkaline/neutral invertase (NIN) and Sus was not significantly different between the two varieties. In trunk bark, ‘Reyan7-33-97’ showed significantly higher NIN activity than ‘PR107’, but not significant between the two varieties for the other sucrose-metabolizing enzymes. In the latex, HbSWEET10a was abundantly expressed, and out of the eight sucrose-metabolizing genes examined, it was the only displaying significant differences in expression between the two varieties, with a higher expression in ‘Reyan7-33-97’. In trunk bark, of the seven sucrose-metabolizing genes examined, the expressions of HbSus3 and HbCIN2 were significantly higher in ‘PR107’ than in ‘Reyan7-33-97’, but HbSUT5 expression was lower in ‘PR107’. These results obtained here laid a foundation for further exploring the molecular interaction between the regulation of sucrose metabolism and latex regeneration.

Key words: Hevea, rubber yield, sucrose metabolism, enzyme activity, gene expression

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