The effect of overexpression of two Brassica CBF/DREB1-like transcription factors on photosynthetic capacity and freezing tolerance in Brassica napus

• Published in: Plant and cell physiology Vol. 46; no. 9; pp. 1525 - 1539
• Main Authors: Savitch, L.V.(Agriculture and Agri-Food Canada, Ottawa), Allard, G, Seki, M, Robert, L.S, Tinker, N.A, Huner, N.P.A, Shinozaki, K, Singh, J
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01.09.2005; Oxford Publishing Limited (England)
• Subjects: 5-bisphosphate carboxylase/oxygenase; 6-bisphosphatase; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Adaptation, Physiological - genetics; ADP-glucose pyrophosphorylase; AGPase; ANATOMIA DE LA PLANTA; ANATOMIE VEGETALE; Base Sequence; Brassica; BRASSICA NAPUS; Brassica napus - genetics; Brassica napus - physiology; CALVIN CYCLE; CBF/DREB1; CICLO DE CALVIN; Cold acclimation; cold regulated; CONGELACION; CONGELATION; COR; CYCLE DE CALVIN; DNA Primers; electron transport; ENZYME ACTIVITY; epoxidation state; EPS; EST; ETR; EXPRESION GENICA; expressed sequence tag; EXPRESSION DES GENES; FACTEUR DE TRANSCRIPTION; FACTORES DE TRANSCRIPCION; FBP; FOTOSINTESIS; FREEZING; Freezing tolerance; fructose 1; GENE EXPRESSION; Gene Expression Profiling; GLK; Golden 2-like transcription factor; IMMUNOBLOTTING; LHC; light-harvesting complex; malate dehydrogenase; MDH; methylviologen; PFD; photon flux density; PHOTOSYNTHESE; PHOTOSYNTHESIS; PLANT ANATOMY; reactive oxygen species; reverse transcription–PCR; ribulose 1; RNA, Messenger - genetics; ROS; RT–PCR; Rubisco; SLW; specific leaf weight; SPS; sucrose-phosphate synthase; TOLERANCE; TOLERANCIA; TRANSCRIPTION FACTORS; Transcription Factors - genetics
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pci165

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/DREBI overexpression in Brassica not only resulted in increased constitutive freezing tolerance but also partially regulated chloroplast development to increase photochemical efficiency and photosynthetic capacity.