Type II Ice-Binding Proteins Isolated from an Arctic Microalga Are Similar to Adhesin-Like Proteins and Increase Freezing Tolerance in Transgenic Plants

Abstract

Microalgal ice-binding proteins (IBPs) in the polar region are poorly understood at the genome-wide level, although they are important for cold adaptation. Through the transcriptome study with the Arctic green alga Chloromonas sp. KNF0032, we identified six Chloromonas IBP genes (CmIBPs), homologous with the previously reported IBPs from Antarctic snow alga CCMP681 and Antarctic Chloromonas sp. They were organized with multiple exon/intron structures and low-temperature-responsive cis-elements in their promoters and abundantly expressed at low temperature. The biological functions of three representative CmIBPs (CmIBP1, CmIBP2 and CmIBP3) were tested using in vitro analysis and transgenic plant system. CmIBP1 had the most effective ice recrystallization inhibition (IRI) activities in both in vitro and transgenic plants, and CmIBP2 and CmIBP3 had followed. All transgenic plants grown under nonacclimated condition were freezing tolerant, and especially 35S::CmIBP1 plants were most effective. After cold acclimation, only 35S::CmIBP2 plants showed slightly increased freezing tolerance. Structurally, the CmIBPs were predicted to have β-solenoid forms with parallel β-sheets and repeated TXT motifs. The repeated TXT structure of CmIBPs appears similar to the AidA domain-containing adhesin-like proteins from methanogens. We have shown that the AidA domain has IRI activity as CmIBPs and phylogenetic analysis also supported that the AidA domains are monophyletic with ice-binding domain of CmIBPs, and these results suggest that CmIBPs are a type of modified adhesins.

Gypsum endolithic phototrophs under moderate climate (Southern Sicily): their diversity and pigment composition

“…The orange pigmented coccoid algae inhabiting fine-grained gypsum at Site 4 (isolate S14 Sicily) were found to be genetically related to green algae from the Chlorophyceae family originated from extreme habitats such as: Antarctic or Arctic freshwater (Jung et al, 2016;Cho et al, 2019), red snow on glacier and green snow fields at King George island (Gálvez et al, 2021), snowfields in Ryder Bay, Antarctic Peninsula (Davey et al, 2019), and Yukidori Valley, Eastern Antarctica (Segawa et al, 2018). Metagenomic sequencing of Arctic gypsum endoliths indicated the presence of few green algal sequences closely matching with Trebouxia sp.…”

Biotechnological Applications of Products Released by Marine Microorganisms for Cold Adaptation Strategies: Polyunsaturated Fatty Acids, Antioxidants, and Antifreeze Proteins

“…Recently, the Arctic green alga Chloromonas sp. KNF0032 was studied using a transcriptomic approach [151]. The study found six Chloromonas IBP genes (CmIBPs) and tested the biological functions of three representative CmIBPs (CmIBP1, CmIBP2, and CmIBP3) using in vitro analysis transgenic plant system, reporting CmIBP1 as the one with the most effective IRI activity.…”

Effect of antifreeze proteins on the freeze-thaw cycle of foods: fundamentals, mechanisms of action, current challenges and recommendations for future work

“…AFPs were successfully cloned from Solanum dulcamara ( Huang and Duman, 2002 ), Dendroctonus armandi ( Fu et al., 2022 ), Brassica rapa ( Liu et al., 2019 ; Dong et al., 2020 ), Zoarces americanus (type III, Hobbs et al., 2020 ), Gadus macrocephalus (type IV, Mao et al., 2018 ), Hypogastrura harveyi ( Chen et al., 2022 ), Lycodichthys dearborni (type III, Huang et al., 2019 ), Cottoidea (type I, Yamazaki et al., 2019 ), Apis cerana cerana ( Xu et al., 2018 ), Ammopiptanthus nanus ( Zhang et al., 2021 ), Larimichthys Crocea ( Qian, 2021 ), Glaciozyma antarctica ( Firdaus-raih et al., 2018 ), Chloromonas sp. KNF0032 (type II, Cho et al., 2019 ), Brachypodium distachyon ( Bredow et al., 2018 ).…”