Skip to main content
SLU publication database (SLUpub)

Research article2018Peer reviewed

Cryopreservation of the Norway spruce tissue culture line able to produce extracellular lignin

Viljamaa, Sonja; Dikareva, Evgenia; Tolonen, Jonne; Edesi, Jaanika; Nickolov, Kaloian; Laitinen, Teresa; Laakso, Tapio; Korpinen, Risto; Saranpaa, Pekka; Jokipii-Lukkari, Soile; Karkonen, Anna; Haggman, Hely

Abstract

A cryopreservation method was developed for a Norway spruce (Picea abies L. Karst.) cell line characterised by highly vacuolated cells and ability to produce natural-like extracellular lignin in a cell suspension culture. Spruce callus cultured in a photoperiod of 16 h light, 8 h dark contained two types of callus morphologies. Soft callus was composed of loosely bound cells that dispersed into single cells and small cell aggregates when transferred into liquid medium. The callus with hard morphology had also cells that were more tightly attached to each other; this callus formed bigger cell aggregates in liquid medium in addition to single cells and small cell aggregates. The hard callus contained higher concentration of intracellular phenolic compounds as compared to soft callus. For cryopreservation, a vitrification method with plant vitrification solution 2 (PVS2) was used. To reduce cellular water content, spruce calli were pre-cultured on a culture medium with increasing sucrose concentration (0.2 and 0.4 M; one day on each). The cryopreservation survival rate of callus with hard morphology was significantly higher than that with soft morphology (45 +/- 8% and 5 +/- 5%, respectively). Pre-culturing in continuous light for several weeks led exclusively to formation of a hard-type callus, which had a survival rate of 48 +/- 16% in cryopreservation. Expression of candidate genes of the monolignol biosynthesis pathway, Fourier transform infrared spectra and pyrolysis breakdown products of extracellular lignin were similar in control cultures and those originating from cryopreserved cells suggesting that cryopreservation is a feasible method for long-term storage of the lignin-forming cell line.

Keywords

Cryopreservation; Lignin formation; Norway spruce cell culture; Picea abies; Vitrification

Published in

Plant Cell, Tissue and Organ Culture
2018, Volume: 133, number: 2, pages: 225-235
Publisher: SPRINGER