Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2019, Vol. 40 ›› Issue (3): 483-489.DOI: 10.3969/j.issn.1000-2561.2019.03.010

• Biotechnology and Tissue Culture • Previous Articles     Next Articles

Cloning of Cassava Phenylalanine Ammonia Lyase Genes and Their Responses to Low Temperature Stress

WU Yuanhang1,LIU Qin1,LIU Pandao2,GUO Pengfei1,LI Min1,JIANG Lingyan1,LUO Lijuan1,*()   

  1. 1. Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, Hainan 570228, China
    2. Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan 571737, China
  • Received:2018-06-05 Revised:2019-01-09 Online:2019-03-15 Published:2019-03-15
  • Contact: LUO Lijuan

Abstract:

Cassava phenylalanine ammonia-lyase encoding genes (MePALs) were identified from the whole genome sequence data. Six MePALs genes, MePAL1-6, were subsequently cloned by RT-PCR from the leaves of the cultivar KU50 and their expression patterns were analyzed, together with PAL activity, total phenolic content, flavonoid content and total antioxidant capacity, in the leaves under low temperature stress treatment (7 ℃). It was found that low temperature treatment resulted in rapid leaf wilting and curling and correspondingly a significant increase in PAL activity, total phenol content, flavonoid content and total antioxidant capacity in the leaves. Real-time PCR analysis showed that the relative expression level of MePAL1 and MePAL2 was 0.83 and 1.19 respectively before low temperature treatment, which was significantly higher than the other 4 MePALs. Low temperature treatment increased the expression of all the six MePAL genes and the up-regulation of MePAL5 was the highest (increased from 50.5 to 142.5 folds). Our preliminary results showed that low temperature treatment increased the expression of MePALs, promoted the synthesis of total phenols and flavonoids, and enhanced anti-oxidative capacities in cassava leaves.

Key words: cassava, low temperature stress, phenylalanine ammonia-lyase gene, flavonoids, antioxidant