Research Center for Environmental Bio-Science and Technology, State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 550081, Guiyang, P.R. China.
University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
BMC Plant Biol. 2022 May 26;22(1):264. doi: 10.1186/s12870-022-03646-1.
Karst habitats are uniquely characterized by high bicarbonate, high nitrate, and low ammonium, which are in-conducive to their growth and biodiversity. The occurrence of inorganic carbon and nitrogen in karst soil profoundly affects the carbon/nitrogen metabolism and adaptability of plants. However, there has been no final conclusion to the joint interactions of carbon and nitrogen metabolism in plants under karst habitats. In this study, we selected a karst-adaptable plant Orychophragmus violaceus (Ov), and a non-karst-adaptable plant Brassica napus (Bn) as experimental plants, and compared their joint effects of carbon and nitrogen metabolism under simulated karst habitats. It was found that the two species had different joint effects of carbon and nitrogen metabolisms. Bicarbonate and nitrate joint promoted photosynthetic activity and glucose metabolism, facilitating the carbon/nitrogen metabolism and growth of Ov, but their impacts on the carbon and nitrogen metabolism were insignificant in Bn. Bicarbonate and ammonium joint inhibited the photosynthesis and nitrogen metabolism, but promoted water use efficiency in Ov, leading to its enhance of growth reduction, ammonium toxicity alleviation, and drought resistance, while they inhibited the water use efficiency of Bn. In general, bicarbonate and nitrate/ammonium more significantly joint affected the carbon and nitrogen metabolism in Ov than Bn, which is vital for Ov to adapt to karst habitats.
喀斯特生境的特点是高碳酸氢盐、高硝酸盐和低氨，这不利于它们的生长和生物多样性。喀斯特土壤中无机碳和氮的存在深刻地影响了植物的碳/氮代谢和适应性。然而，关于喀斯特生境下植物碳氮代谢的联合作用，还没有最终结论。在这项研究中，我们选择了一种适应喀斯特环境的植物 Orychophragmus violaceus（Ov）和一种不适应喀斯特环境的植物 Brassica napus（Bn）作为实验植物，比较了它们在模拟喀斯特生境下碳氮代谢的联合作用。结果发现，这两个物种的碳氮代谢联合作用不同。碳酸氢盐和硝酸盐联合促进了光合作用和葡萄糖代谢，有利于 Ov 的碳/氮代谢和生长，但对 Bn 的碳氮代谢影响不大。碳酸氢盐和铵盐联合抑制了光合作用和氮代谢，但促进了 Ov 的水分利用效率，导致其生长减少、铵毒性缓解和抗旱性增强，而对 Bn 的水分利用效率则有抑制作用。总的来说，碳酸氢盐和硝酸盐/铵盐对 Ov 的碳氮代谢的联合影响比 Bn 更为显著，这对于 Ov 适应喀斯特生境至关重要。
