Department of Food Science, Aarhus University, Aarhus, Denmark.
National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, Nanjing, China.
Plant Physiol Biochem. 2020 Sep;154:353-359. doi: 10.1016/j.plaphy.2020.06.030. Epub 2020 Jun 20.
Our aim was to understand how moderately increased light intensities influenced the response of chickpea to high temperature. Three chickpea genotypes (Acc#3, Acc#7 and Acc#8) were treated at control (26 °C and 300 μmol m s photosynthetic photon flux density/PPFD), high temperature (38 °C and 300 μmol m s PPFD), increased light intensity (26 °C and 600 μmol m s PPFD) and combination of increased light and temperature (38 °C and 600 μmol m s PPFD). The net photosynthetic rate (P) of Acc#3 and Acc#8 significantly decreased at high temperature regardless of light intensity. The P of all three genotypes at increased light intensity was significantly higher than that at high temperature. The intracellular CO concentration (C), stomatal conductance (g) and transpiration rate (E) of Acc#3 and Acc#8 at increased light intensity with or without high temperature significantly decreased in comparison with control and individually high temperature treatment. The relative water content of Acc#3 at high temperature and the combination treatment decreased as compared with control. The relative water content of Acc#7 at control was higher than the other three treatments. The F/F (Maximum quantum efficiency of photosystem II) of leaves from the three genotypes at 38 °C were lower than at 26 °C regardless of light intensity. The high temperature decreased chlorophyll content in the lower bottom leaf of Acc#7 and Acc#8 than control. In conclusion, chickpeas showed a higher net photosynthetic rate at increased light intensity to withstand heat stress, which was genotype-dependent. Physiological responses of different chickpea genotypes to increased temperature and light intensity indicated that distinct responsive mechanism of photosynthesis. This study provides information on how chickpea respond to high temperature and increased light intensity, which will help us to improve chickpea to deal with future climate changes.
我们的目的是了解适度增加的光强如何影响鹰嘴豆对高温的反应。对三种鹰嘴豆基因型（Acc#3、Acc#7 和 Acc#8）分别在对照（26°C 和 300μmol·m-2·s-1 光合光子通量密度/PPFD）、高温（38°C 和 300μmol·m-2·s-1 PPFD）、增加光强（26°C 和 600μmol·m-2·s-1 PPFD）和增加光强与高温组合（38°C 和 600μmol·m-2·s-1 PPFD）下进行处理。无论光强如何，Acc#3 和 Acc#8 的净光合速率（P）在高温下均显著降低。在增加的光强下，所有三种基因型的 P 均显著高于高温下的 P。Acc#3 和 Acc#8 在增加的光强下，无论是否存在高温，其胞内 CO2 浓度（C）、气孔导度（g）和蒸腾速率（E）均显著低于对照和单独高温处理。Acc#3 在高温和组合处理下的相对水含量与对照相比有所下降。Acc#7 在对照下的相对水含量高于其他三种处理。无论光强如何，三种基因型叶片在 38°C 时的 F/F（光系统 II 的最大量子效率）均低于 26°C。高温降低了 Acc#7 和 Acc#8 下部叶片的叶绿素含量，低于对照。综上所述，鹰嘴豆在增加的光强下表现出更高的净光合速率以抵御热胁迫，这与基因型有关。不同鹰嘴豆基因型对增加的温度和光强的生理响应表明，光合作用有不同的响应机制。本研究提供了鹰嘴豆对高温和增加的光强的响应信息，这将有助于我们改善鹰嘴豆以应对未来的气候变化。
