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- Kurepin, Leonid V., et al.
(författare)
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Role of CBFs as Integrators of Chloroplast Redox, Phytochrome and Plant Hormone Signaling during Cold Acclimation
- 2013
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 14:6, s. 12729-12763
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Forskningsöversikt (refereegranskat)abstract
- Cold acclimation of winter cereals and other winter hardy species is a prerequisite to increase subsequent freezing tolerance. Low temperatures upregulate the expression of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) which in turn induce the expression of COLD-REGULATED (COR) genes. We summarize evidence which indicates that the integration of these interactions is responsible for the dwarf phenotype and enhanced photosynthetic performance associated with cold-acclimated and CBF-overexpressing plants. Plants overexpressing CBFs but grown at warm temperatures mimic the cold-tolerant, dwarf, compact phenotype; increased photosynthetic performance; and biomass accumulation typically associated with cold-acclimated plants. In this review, we propose a model whereby the cold acclimation signal is perceived by plants through an integration of low temperature and changes in light intensity, as well as changes in light quality. Such integration leads to the activation of the CBF-regulon and subsequent upregulation of COR gene and GA 2-oxidase (GA2ox) expression which results in a dwarf phenotype coupled with increased freezing tolerance and enhanced photosynthetic performance. We conclude that, due to their photoautotrophic nature, plants do not rely on a single low temperature sensor, but integrate changes in light intensity, light quality, and membrane viscosity in order to establish the cold-acclimated state. CBFs appear to act as master regulators of these interconnecting sensing/signaling pathways.
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| 2. |
- Kurepin, Leonid V., et al.
(författare)
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Contrasting acclimation abilities of two dominant boreal conifers to elevated CO2 and temperature
- 2018
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Ingår i: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 41:6, s. 1331-1345
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Tidskriftsartikel (refereegranskat)abstract
- High latitude forests will experience large changes in temperature and CO2 concentrations this century. We evaluated the effects of future climate conditions on 2 dominant boreal tree species, Pinus sylvestris L. and Picea abies (L.) H. Karst, exposing seedlings to 3 seasons of ambient (430 ppm) or elevated CO2 (750 ppm) and ambient temperatures, a + 4 degrees C warming or a + 8 degrees C warming. Pinus sylvestris responded positively to warming: seedlings developed a larger canopy, maintained high net CO2 assimilation rates (Anet), and acclimated dark respiration (Rdark). In contrast, carbon fluxes in Picea abies were negatively impacted by warming: maximum rates of Anet decreased, electron transport was redirected to alternative electron acceptors, and thermal acclimation of Rdark was weak. Elevated CO2 tended to exacerbate these effects in warm-grown Picea abies, and by the end of the experiment Picea abies from the +8 degrees C, high CO2 treatment produced fewer buds than they had 3 years earlier. Treatments had little effect on leaf and wood anatomy. Our results highlight that species within the same plant functional type may show opposite responses to warming and imply that Picea abies may be particularly vulnerable to warming due to low plasticity in photosynthetic and respiratory metabolism.
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| 4. |
- Kurepin, Leonid V., et al.
(författare)
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Stress-related hormones and glycinebetaine interplay in protection of photosynthesis under abiotic stress conditions
- 2015
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Ingår i: Photosynthesis Research. - : Springer Science and Business Media LLC. - 0166-8595 .- 1573-5079. ; 126:2-3, s. 221-235
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Forskningsöversikt (refereegranskat)abstract
- Plants subjected to abiotic stresses such as extreme high and low temperatures, drought or salinity, often exhibit decreased vegetative growth and reduced reproductive capabilities. This is often associated with decreased photosynthesis via an increase in photoinhibition, and accompanied by rapid changes in endogenous levels of stress-related hormones such as abscisic acid (ABA), salicylic acid (SA) and ethylene. However, certain plant species and/or genotypes exhibit greater tolerance to abiotic stress because they are capable of accumulating endogenous levels of the zwitterionic osmolyte-glycinebetaine (GB). The accumulation of GB via natural production, exogenous application or genetic engineering, enhances plant osmoregulation and thus increases abiotic stress tolerance. The final steps of GB biosynthesis occur in chloroplasts where GB has been shown to play a key role in increasing the protection of soluble stromal and lumenal enzymes, lipids and proteins, of the photosynthetic apparatus. In addition, we suggest that the stress-induced GB biosynthesis pathway may well serve as an additional or alternative biochemical sink, one which consumes excess photosynthesis-generated electrons, thus protecting photosynthetic apparatus from overreduction. Glycinebetaine biosynthesis in chloroplasts is up-regulated by increases in endogenous ABA or SA levels. In this review, we propose and discuss a model describing the close interaction and synergistic physiological effects of GB and ABA in the process of cold acclimation of higher plants.
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