Fructan accumulation and transcription of candidate genes during cold acclimation in three varieties of Poa pratensis

• Published in: Journal of Plant Physiology
• Main Authors: Rao, R Shyama Prasad, Andersen, Jeppe Reitan, Dionisio, Giuseppe, Boelt, Birte
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: cold acclimation; fructan exohydrolase; fructosyltransferase; gene expression; poa pratensis; Norway; Northern Norway
• Online Access: https://pure.au.dk/portal/da/publications/fructan-accumulation-and-transcription-of-candidate-genes-during-cold-acclimation-in-three-varieties-of-poa-pratensis(6d13bfe0-3726-11df-8b17-000ea68e967b).html; https://doi.org/10.1016/j.jplph.2010.07.019

Poa pratensis , a type species for the grass family ( Poaceae ), is an important cool season grass that accumulates fructans as a polysaccharide reserve. We studied fructan contents and expression of candidate fructan metabolism genes during cold acclimation in three varieties of P. pratensis adapted to different environments: Northern Norway, Denmark, and the Netherlands. Fructan content increased significantly during cold acclimation and varieties showed significant differences in the level of fructan accumulation. cDNA sequences of putative fructosyltransferase ( FT ), fructan exohydrolase ( FEH ), and cold acclimation protein ( CAP ) genes were identified and cloned. In agreement with a function in fructan biosynthesis, transcription of a putative sucrose:fructan 6-fructosyltransferase ( Pp6-SFT ) gene was induced during cold acclimation and fructan accumulation in all three P. pratensis varieties. Transcription of putative PpFEH and PpCAP genes was also induced by cold acclimation; however, transcription of these two genes was several-fold higher in the variety from Norway compared to the other two varieties. The results presented here suggest that Pp6-SFT is involved in fructan biosynthesis in P. pratensis . FEHs have previously been suggested to be involved in fructan biosynthesis and freezing tolerance, and induced expression of PpFEH during fructan accumulation could also suggest a role in fructan biosynthesis. However, based on the different PpFEH transcription rates among varieties and similar expression of PpFEH and PpCAP , we suggest that PpFEH is more likely to be involved in mediating freezing tolerance, e.g., by regulating the cell osmotic potential through fructan degradation. Poa pratensis , a type species for the grass family ( Poaceae ), is an important cool season grass that accumulates fructans as a polysaccharide reserve. We studied fructan contents and expression of candidate fructan metabolism genes during cold acclimation in three varieties of P. pratensis adapted to different ...