Brilhaus Dominik, Bräutigam Andrea, Mettler-Altmann Tabea, Winter Klaus, Weber Andreas P M
Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, D-40225 Düsseldorf, Germany (D.B., A.B., T.M.-A., A.P.M.W.); and Smithsonian Tropical Research Institute, Balboa, Ancón, Republic of Panama (K.W.).
Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, D-40225 Düsseldorf, Germany (D.B., A.B., T.M.-A., A.P.M.W.); and Smithsonian Tropical Research Institute, Balboa, Ancón, Republic of Panama (K.W.)
Plant Physiol. 2016 Jan;170(1):102-22. doi: 10.1104/pp.15.01076. Epub 2015 Nov 3.
Drought tolerance is a key factor for agriculture in the 21st century as it is a major determinant of plant survival in natural ecosystems as well as crop productivity. Plants have evolved a range of mechanisms to cope with drought, including a specialized type of photosynthesis termed Crassulacean acid metabolism (CAM). CAM is associated with stomatal closure during the day as atmospheric CO2 is assimilated primarily during the night, thus reducing transpirational water loss. The tropical herbaceous perennial species Talinum triangulare is capable of transitioning, in a facultative, reversible manner, from C3 photosynthesis to weakly expressed CAM in response to drought stress. The transcriptional regulation of this transition has been studied. Combining mRNA-Seq with targeted metabolite measurements, we found highly elevated levels of CAM-cycle enzyme transcripts and their metabolic products in T. triangulare leaves upon water deprivation. The carbohydrate metabolism is rewired to reduce the use of reserves for growth to support the CAM-cycle and the synthesis of compatible solutes. This large-scale expression dataset of drought-induced CAM demonstrates transcriptional regulation of the C3-CAM transition. We identified candidate transcription factors to mediate this photosynthetic plasticity, which may contribute in the future to the design of more drought-tolerant crops via engineered CAM.
耐旱性是21世纪农业的关键因素，因为它是自然生态系统中植物生存以及作物生产力的主要决定因素。植物已经进化出一系列应对干旱的机制，包括一种特殊类型的光合作用，称为景天酸代谢（CAM）。CAM与白天气孔关闭有关，因为大气中的二氧化碳主要在夜间被同化，从而减少蒸腾失水。热带多年生草本植物三角叶土人参能够以兼性、可逆的方式从C3光合作用转变为对干旱胁迫响应的弱表达CAM。已经对这种转变的转录调控进行了研究。结合mRNA测序和靶向代谢物测量，我们发现缺水时三角叶土人参叶片中CAM循环酶转录本及其代谢产物的水平大幅升高。碳水化合物代谢被重新调整，以减少用于生长的储备的使用，以支持CAM循环和相容性溶质的合成。这个干旱诱导的CAM的大规模表达数据集证明了C3-CAM转变的转录调控。我们鉴定了介导这种光合可塑性的候选转录因子，这可能在未来通过工程化CAM有助于设计更耐旱的作物。
