Difference in proteome response to cold acclimation in Zoysia japonica cultivars with different levels of freeze tolerance

Authors: BROWN, JESSICA - North Carolina State University; HOLLOWAY, MCCAMY - North Carolina State University; DACOSTA, MICHELE - University Of Massachusetts; BERNSTEIN, RACHAEL - University Of Massachusetts; LU, JEFFERSON - University Of Massachusetts; Tuong, Tan; PATTON, AARON - Purdue University; DUNNE, JEFFREY - North Carolina State University; ARELLANO, CONSUELO - North Carolina State University; Livingston, David; MILLA-LEWIS, SUSANA - North Carolina State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2020
Publication Date: 7/20/2021
Citation: Brown, J., Holloway, M., Dacosta, M., Bernstein, R., Lu, J., Tuong, T.D., Patton, A., Dunne, J., Arellano, C., Livingston, D.P., Milla-Lewis, S. 2021. Difference in proteome response to cold acclimation in Zoysia japonica cultivars with different levels of freeze tolerance. Crop Science. 60:2744-2756.

Interpretive Summary: Zoysiagrass is an important turf species grown in southern areas of the US. Freezing tolerance is an important factor in the cultivation of this grass. In this study the relationship between cold acclimation, protein expression, and freeze tolerance in cold-acclimated (CA) and non-acclimated (NCA) plants of a freezing tolerant and non freezing tolerant cultivar were studied. In addition a protein analysis identified 62 protien spots that were 2-fold higher in cold acclimated plants suggesting a complex series of metabolic changes contributes to acclimation in this species. Several major proteins that have previously been correlated with freezing tolerance in other species were identified using a sophisticated form of mass spectroscopy known as MALDI-TOF. These proteins will not only contribute to our understanding of freezing tolerance in general but could also provide breeders with valuable screening tools for selecting freezing tolerant germplasm.

Technical Abstract: Zoysiagrasses (Zoysia spp.) are warm season turfgrasses primarily grown in the southern and transition zones of the United States. An understanding of the physiological changes that zoysiagrasses undergo during cold acclimation may shed light on physiological phenotypic traits useful in selection of freeze tolerant genotypes. We investigated the relationship between cold acclimation, protein expression, and freeze tolerance in cold-acclimated (CA) and non-acclimated (NCA) plants of Zoysia japonica Steud. cultivars ‘Meyer’ (freeze-tolerant) and ‘Victoria’ (freeze susceptible). Freeze tolerance was assessed using chambers reaching -6, -8, -10, and -12ºC. Additionally, meristematic tissues from the grass crowns of ‘Meyer’ and ‘Victoria’ were harvested for proteomic analysis after a four week cold acclimation period. Freeze testing indicated that cold acclimation accounted for a 1.9-fold increase in plant survival compared to the non-acclimation treatment. Overall, proteomic analysis identified 62 protein spots having at least a twofold change in abundance under cold acclimation. Nine and 22 unique protein spots were identified for Meyer and Victoria, respectively, with increased abundance (up-regulated) or decreased abundance (down-regulated). In addition, 23 shared protein spots were found among the two cultivars having differential expression in response to cold acclimation. In Meyer, protein response to cold acclimation was primarily upregulated, while in Victoria, protein response was primarily downregulated. These cold acclimation responsive proteins were found to be involved primarily in transcription, metabolism, protein destination and storage, and energy production. As identified through MALDI-TOF/TOF mass spectrometry followed matching of protein homologues against the NCBI Arabidopsis database, major proteins of interest for their association with cold acclimation were LEA 3, MAPK, SOD, GAST1, Phytochrome A, ATP synthase, AGP, PLD, and PSII. Further investigation of these proteins and their functional categories may increase our understanding of the differences in freezing tolerance among zoysiagrass germplasm.