title: The effect of overexpression of two Brassica CBF/DREB1-like transcription factors on photosynthetic capacity and freezing tolerance in Brassica napus.
abstract: The effects of overexpression of two Brassica CBF/DREB1-like transcription factors (BNCBF5 and 17) in Brassica napus cv. Westar were studied. In addition to developing constitutive freezing tolerance and constitutively accumulating COR gene mRNAs, BNCBF5- and 17-overexpressing plants also accumulate moderate transcript levels of genes involved in photosynthesis and chloroplast development as identified by microarray and Northern analyses. These include GLK1- and GLK2-like transcription factors involved in chloroplast photosynthetic development, chloroplast stroma cyclophilin ROC4 (AtCYP20-3), beta-amylase and triose-P/Pi translocator. In parallel with these changes, increases in photosynthetic efficiency and capacity, pigment pool sizes, increased capacities of the Calvin cycle enzymes, and enzymes of starch and sucrose biosynthesis, as well as glycolysis and oxaloacetate/malate exchange are seen, suggesting that BNCBF overexpression has partially mimicked cold-induced photosynthetic acclimation constitutively. Taken together, these results suggest that BNCBF/DREB1 overexpression in Brassica not only resulted in increased constitutive freezing tolerance but also partially regulated chloroplast development to increase photochemical efficiency and photosynthetic capacity.
authors: Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Central Experimental Farm, Ottawa, Ontario, Canada, K1A 0C6.
authors: Leonid V
authors: LV
authors: Savitch
authors: Ghislaine
authors: G
authors: Allard
authors: Motoaki
authors: M
authors: Seki
authors: Laurian S
authors: LS
authors: Robert
authors: Nicholas A
authors: NA
authors: Tinker
authors: Norman P A
authors: NP
authors: Huner
authors: Kazuo
authors: K
authors: Shinozaki
authors: Jas
authors: J
authors: Singh
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D001483:Base Sequence; D029688:Brassica napus / Q000235:genetics* / Q000502:physiology*; D017931:DNA Primers; D005615:Freezing; D020869:Gene Expression Profiling; D010788:Photosynthesis; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D014157:Transcription Factors