Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (10): 2769-2776.DOI: 10.3969/j.issn.1000-2561.2021.10.004

• Variety Breeding and Genetic Diversity of Tropical Crops • Previous Articles     Next Articles

Premature Mutation Frequencies in Coding Region of Gene 12G132600 Encoding Alpha-hydroxy Nitrile Lyase in Cassava Germplasms

ZHOU Xincheng1,2, CHEN Xin1,2, LU Cheng1,2, LIAO Mingxin1,2, WANG Haiyan1,2, TANG Qingjie3, REN Junfang4,5,*(), WANG Wenquan1,2,*()   

  1. 1. Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences. Haikou, Haina 571101, China
    2. Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture and Rural Affairs. Haikou, Hainan 571101, China
    3. Alimentarn Crop Institute, Hainan Academy of Agricultural Sciences, Haikou, Hainan 571100, China
    4. Tropical Horticulture Research Institute, Hainan Academy of Agricultural Sciences, Haikou, Hainan 571100, China
    5. Hainan Key Laboratory for innovative Development and Utilization of Tropical Special Economic Plants. Haikou, Hainan 571100, China.
  • Received:2021-06-17 Revised:2021-07-27 Online:2021-10-25 Published:2021-11-25
  • Contact: REN Junfang,WANG Wenquan

Abstract:

Cassava is an important food crop in the world. The presence of high-level cyanogenic glucosides and HCN produced poses a major nutritive drawback and means a higher labor costs to remove these toxic substances. Cyanogensis is an important protective mechanism for plant to avoid grazing by animals. Alpha-hydroxy nitrile lyase (HNL) plays a key role in cyanogensis reaction. We found that there was a premature termination mutation in the coding sequence of HNL gene of cassava variety SC8, which would result in short length in protein encoded and could affect the function of the protein. These researches would give useful information about the role of the point mutation and provide new ideals for selecting cassava accessions with low-content hydrocyanic acid in molecular breeding. Firstly we surveyed the resequencing data of 251 cassava varieties from all around the world to characterize the same mutation site in HNL gene and found that there were sixty accessions belonging to cultivated cassava harboring the same mutation as SC8, indicting the premature mutation occurred during or after cassava domestication. We cloned and sequenced the orthologous genes of 12G132600 in SC9 by PCR and compared the corresponding sequence of TME3 from the genome assembly. The results further strengthened the evidence of this premature mutation in cassava varieties.

Key words: cassava, hydrocyanic acid, alpha-hydroxy nitrile lyase, germplasms, gene mutation

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