Effect of bud burst forcing on transcript expression of selected genes in needles of Norway spruce during autumn

• Published in: Plant physiology and biochemistry 2009-08, Vol.47 (8), p.681-689
• Main Authors: Asante, Daniel K.A., Yakovlev, Igor A., Fossdal, Carl Gunnar, Timmerhaus, Gerrit, Partanen, Jouni, Johnsen, Øystein
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biology and morphogenesis of the reproductive apparatus. Photoperiodism, vernalisation; Bud burst; Chilling; Dormancy; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene Expression Profiling; Genes, Plant; Germination and dormancy; Multivariate Analysis; Picea - genetics; Picea - growth & development; Picea - metabolism; Picea abies; Picea abies (L.) Karst; Plant Leaves - genetics; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant physiology and development; Polymerase Chain Reaction; qRT-PCR; Seasons; Transcription, Genetic; Trees - metabolism; Vegetative and sexual reproduction, floral biology, fructification; Vernalization
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2009.03.004

Expression of selected genes in needles of Norway spruce ( Picea abies [L.] Karst) was investigated by following their transcription levels during late autumn. Transcription was assessed in mature needles which likely serve as sensor of environmental cues that enable trees in the temperate and boreal regions to change between stages of growth, frost tolerance and bud dormancy. Samples were collected from grafts kept under outdoor conditions and after bud burst forcing in greenhouse at 20 °C (12 h darkness) for one week. Transcription was assayed with real-time RT-PCR. During the sampling period, chilling requirement was partially fulfilled, and time to bud burst after forcing was decreased. Of the 27 transcripts studied, expression of 16 was significantly affected either by forcing, sampling time, or interaction between them. PaSAP, PaACP, PaSGS3, PaWRKY, PaDIR9, PaCCCH and dehydrin genes responded drastically to forcing temperatures at all sampling points, showing no correlation with readiness for bud burst. Expression patterns of some vernalization pathway gene homologs PaVIN3, and also of PaMDC, PaLOV1 and PaDAL3 had a clear opposite trends between forcing and outdoor conditions, which could imply their role in chilling accumulation and bud burst regulation/cold acclimation. These genes could constitute putative candidates for further detailed study, whose regulation in needles may be involved in preparation towards bud burst and chilling accumulation sensing.