Comparative In-silico Analysis of the Cold Responsive ICE1 and ICE2 Genes in Zoysiagrasses

Kaur Chetan1   Young-Sun  Kim2,3   Jeong-Ho  Youn4   Eun-Ji  Bae5   Geung-Joo  Lee1,6,*   

1Department of Horticulture, Chungnam National University, Daejeon 34134, Korea
2Division of Life and Environmental Science, Daegu University, Gyeongsan 38453, Korea
3Institute of Natural Sciences, Daegu University, Gyeongsan 38453, Korea
4Hanul Co., Ltd., Hapcheon 13206, Korea
5Forest Biomaterials Research Center, National Institute of Forest Science, Jinju 52817, Korea
6Department of Smart Agriculture Systems, Chungnam National University, Daejeon 34134, Korea


Inducer of CBF (C-repeat binding factors) expression 1, 2 (ICE1/2) is an important transcription factor that plays a significant role in the cold stress response pathway. Zoysiagrasses are warm-season turfgrasses and are prone to browning at the starting of winter. By understanding the cold response mechanism, the cold tolerance of some zoysiagrasses such as Zoysia matrella or Z. pacifica showing less cold hardiness can be improved to withstand low temperatures. Arabidopsis and Z. japonica ICE1, 2 have already been characterized and reported. Using in-silico analysis, we predicted the putative ICE1, 2 genes in Z. matrella and Z. pacifica. The comparative sequence analyses revealed conservation of the bHLH (basic helix-loop-helix) domain in the putative ICE1 and ICE2 genes in Z. matrella and Z. pacifica. Also, two copies of ICE2 were seen in Z. matrella. There were huge variations in the immediate regulatory region of the ICE1 and ICE2 genes which may be a reason for different cold tolerance levels in the three Zoysiagrasses. The predicted sequences of the ICE1,2 genes in Z. matrella and Z. pacifica can be utilized to further investigate interactions with CBF3 and their implications in cold stress tolerance, which will provide new insight into molecular mechanisms in regulating cold tolerance.

Figures & Tables

Fig. 1. Conserved domain analysis of the Zoysia A) Inducer of CBF expression 1 (ICE1 ) putative protein sequences and B) Inducer of CBF expression 2 (ICE2 ) putative protein sequences. Two major domains related to the ICE1 protein; bHLH_AtAMS_like (in blue) and ACT_UUR-ACR-like (in yellow) were identified in all three zoysiagrasses. An additional domain, belonging to the PLN02983 superfamily was identified in Z. matrella ICE1 (Zmw-ICE1 ) and Z. pacifica ICE1 (Zpz-ICE1 ) (highlighted in grey). The single amino acid polymorphic sites are in red, and the in/del regions have been highlighted in green. cov: Coverage; pid: Percent identity; Zjn: Z. japonica .