Dobrá Jana, Černý Martin, Štorchová Helena, Dobrev Petre, Skalák Jan, Jedelský Petr L, Lukšanová Hana, Gaudinová Alena, Pešek Bedřich, Malbeck Jiří, Vanek Tomas, Brzobohatý Břetislav, Vanková Radomíra
Institute of Experimental Botany AS CR, Rozvojová 263, CZ-16502 Prague 6, Czech Republic.
Laboratory of Plant Molecular Biology, Institute of Biophysics AS CR, v.v.i. and CEITEC-Central European Institute of Technology, Mendel University in Brno, CZ-61300 Brno, Czech Republic.
Plant Sci. 2015 Feb;231:52-61. doi: 10.1016/j.plantsci.2014.11.005. Epub 2014 Nov 25.
Targeting of the heat stress (HS, 40°C) to shoots, roots or whole plants substantially affects Arabidopsis physiological responses. Effective stress targeting was proved by determination of the expression of HS markers, HsfA2 and HSA32, which were quickly stimulated in the targeted organ(s), but remained low in non-stressed tissues for at least 2h. When shoots or whole plants were subjected to HS, a transient decrease in abscisic acid, accompanied by a small increase in active cytokinin levels, was observed in leaves, consistent with stimulation of transpiration, the main cooling mechanism in leaves. HS application targeted to part of plant resulted in a rapid stimulation of expression of components of cytokinin signaling pathway (especially of receptor genes) in the non-exposed tissues, which indicated fast inter-organ communication. Under all HS treatments, shoot apices responded by transient elevation of active cytokinin contents and stimulation of transcription of genes involved in photosynthesis and carbohydrate metabolism. Duration of this stimulation was negatively correlated with stress strength. The impact of targeted HS on the expression of 63 selected genes, including those coding regulatory 14-3-3 proteins, was compared. Stimulation of GRF9 (GRF14μ) in stressed organs after 2-6h may be associated with plant stress adaptation.
将热胁迫（HS，40°C）施加于地上部、根部或整株植物会显著影响拟南芥的生理反应。通过测定HS标记基因HsfA2和HSA32的表达，证明了有效的胁迫施加，这些基因在目标器官中迅速被激活，但在未受胁迫的组织中至少2小时内仍保持低水平。当地上部或整株植物受到热胁迫时，叶片中脱落酸短暂下降，同时活性细胞分裂素水平略有升高，这与蒸腾作用的增强一致，蒸腾作用是叶片主要的降温机制。对植物部分部位施加热胁迫导致未暴露组织中细胞分裂素信号通路成分（尤其是受体基因）的表达迅速激活，这表明存在快速的器官间通讯。在所有热胁迫处理下，茎尖通过活性细胞分裂素含量的短暂升高以及参与光合作用和碳水化合物代谢的基因转录的激活做出反应。这种激活的持续时间与胁迫强度呈负相关。比较了靶向热胁迫对63个选定基因表达的影响，包括那些编码调节性14-3-3蛋白的基因。胁迫2-6小时后，受胁迫器官中GRF9（GRF14μ）的激活可能与植物胁迫适应有关。
