Five winter oilseed rape cultivars (Benefit, Californium, Cortes, Ladoga, Navajo) were subjected to 30 days of cold treatment (4 °C) to examine the effect of cold on acquired frost tolerance (FT), dehydrin (DHN) content, and photosynthesis-related parameters. The main aim of this study was to determine whether there are relationships between FT (expressed as LT50 values) and the other parameters measured in the cultivars. While the cultivar Benefit accumulated two types of DHNs (D45 and D35), the other cultivars accumulated three additional DHNs (D97, D47, and D37). The similar-sized DHNs (D45 and D47) were the most abundant; the others exhibited significantly lower accumulations. The highest correlations were detected between LT50 and DHN accumulation (r=-0.815), intrinsic water use efficiency (WUEi; r=-0.643), net photosynthetic rate (r=-0.628), stomatal conductance (r=0.511), and intracellular/intercellular CO2 concentration (r=0.505). Those cultivars that exhibited higher Pn rate in cold (and further a significant increase in WUEi) had higher levels of DHNs and also higher FT. No significant correlation was observed between LT50 and E, PRI, or NDVI. Overall, we have shown the selected physiological parameters to be able to distinguish different FT cultivars of winter oilseed rape.

• Klíčová slova
• ABA, AP, BEN, CA, CAL, COR, COR/LEA, Ci, Cold acclimation, D47, D45, D37 and D35 stand for dehydrin accumulation according to their different molecular masses from protein gel blot analysis (∼97, ∼47, ∼45, ∼37 and ∼35 kD), D97, DHN, Dehydrin, E, FT, Frost tolerance, GS, LAD, LT(50), NAV, NBT/BCIP, NDVI, PCA, PRI, Photosynthesis, Pn, SDS–PAGE, WUE, WUEi, Winter oilseed rape, abscisic acid, alkaline phosphatase, cold acclimation or cold acclimated, cold regulated/late embryogenesis abundant, cultivar Benefit, cultivar Californium, cultivar Cortes, cultivar Ladoga, cultivar Navajo, cultivars, cvs, dehydrin, frost tolerance, internal leaf CO(2) concentration, intrinsic water use efficiency (Pn/GS), lethal temperature for 50% of plants, net photosynthetic rate, nitro-blue tetrazolium/5-bromo-4-chloro-3′-indolyphosphate, normalized difference vegetation index, photochemical reflectance index, principal component analysis, sodium dodecyl sulphate polyacrylamide gel electrophoresis, stomatal conductance, transpiration, water use efficiency (Pn/E),
• MeSH
• aklimatizace MeSH
• analýza hlavních komponent MeSH
• analýza rozptylu MeSH
• Brassica napus fyziologie   MeSH
• fotosyntéza fyziologie   MeSH
• fyziologická adaptace * MeSH
• roční období * MeSH
• rostlinné proteiny metabolismus   MeSH
• voda fyziologie   MeSH
• zmrazování * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dehydrin proteins, plant MeSH Prohlížeč
• rostlinné proteiny MeSH
• voda MeSH

The dynamic behaviour of seeds in soil seed banks depends on their ability to act as sophisticated environmental sensors to adjust their sensitivity thresholds for germination by dormancy mechanisms. Here we show that prolonged incubation of sugar beet fruits at low temperature (chilling at 5°C, generally known to release seed dormancy of many species) can induce secondary nondeep physiological dormancy of an apparently nondormant crop species. The physiological and biophysical mechanisms underpinning this cold-induced secondary dormancy include the chilling-induced accumulation of abscisic acid in the seeds, a reduction in the embryo growth potential and a block in weakening of the endosperm covering the embryonic root. Transcriptome analysis revealed distinct gene expression patterns in the different temperature regimes and upon secondary dormancy induction and maintenance. The chilling caused reduced expression of cell wall remodelling protein genes required for embryo cell elongation growth and endosperm weakening, as well as increased expression of seed maturation genes, such as for late embryogenesis abundant proteins. A model integrating the hormonal signalling and master regulator expression with the temperature-control of seed dormancy and maturation programmes is proposed. The revealed mechanisms of the cold-induced secondary dormancy are important for climate-smart agriculture and food security.

• Klíčová slova
• coat dormancy, cold-induced dormancy, embryo growth potential, endosperm weakening, germination temperature, secondary dormancy, seed transcriptomes, sugar beet,
• MeSH
• Beta vulgaris * genetika   MeSH
• klíčení fyziologie   MeSH
• kyselina abscisová metabolismus   MeSH
• semena rostlinná fyziologie   MeSH
• vegetační klid genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina abscisová MeSH