Vicente Rubén, Bolger Anthony M, Martínez-Carrasco Rafael, Pérez Pilar, Gutiérrez Elena, Usadel Björn, Morcuende Rosa
Institute of Natural Resources and Agrobiology of Salamanca (IRNASA), Consejo Superior de Investigaciones Científicas (CSIC), Salamanca, Spain.
Institute for Biology 1, RWTH Aachen University, Aachen, Germany.
Front Plant Sci. 2019 Dec 6;10:1605. doi: 10.3389/fpls.2019.01605. eCollection 2019.
Global warming is becoming a significant problem for food security, particularly in the Mediterranean basin. The use of molecular techniques to study gene-level responses to environmental changes in non-model organisms is increasing and may help to improve the mechanistic understanding of durum wheat response to elevated CO and high temperature. With this purpose, we performed transcriptome RNA sequencing (RNA-Seq) analyses combined with physiological and biochemical studies in the flag leaf of plants grown in field chambers at ear emergence. Enhanced photosynthesis by elevated CO was accompanied by an increase in biomass and starch and fructan content, and a decrease in N compounds, as chlorophyll, soluble proteins, and Rubisco content, in association with a decline of nitrate reductase and initial and total Rubisco activities. While high temperature led to a decline of chlorophyll, Rubisco activity, and protein content, the glucose content increased and starch decreased. Furthermore, elevated CO induced several genes involved in mitochondrial electron transport, a few genes for photosynthesis and fructan synthesis, and most of the genes involved in secondary metabolism and gibberellin and jasmonate metabolism, whereas those related to light harvesting, N assimilation, and other hormone pathways were repressed. High temperature repressed genes for C, energy, N, lipid, secondary, and hormone metabolisms. Under the combined increases in atmospheric CO and temperature, the transcript profile resembled that previously reported for high temperature, although elevated CO partly alleviated the downregulation of primary and secondary metabolism genes. The results suggest that there was a reprogramming of primary and secondary metabolism under the future climatic scenario, leading to coordinated regulation of C-N metabolism towards C-rich metabolites at elevated CO and a shift away from C-rich secondary metabolites at high temperature. Several candidate genes differentially expressed were identified, including protein kinases, receptor kinases, and transcription factors.
全球变暖正成为粮食安全的一个重大问题，在地中海盆地尤其如此。利用分子技术研究非模式生物对环境变化的基因水平反应的情况日益增多，这可能有助于增进对硬粒小麦对二氧化碳浓度升高和高温反应的机制理解。为此，我们在抽穗期在田间试验箱中种植的植物的旗叶上进行了转录组RNA测序（RNA-Seq）分析，并结合生理和生化研究。二氧化碳浓度升高增强光合作用的同时，生物量、淀粉和果聚糖含量增加，氮化合物（如叶绿素、可溶性蛋白质和核酮糖-1,5-二磷酸羧化酶含量）减少，同时硝酸还原酶以及初始和总核酮糖-1,5-二磷酸羧化酶活性下降。而高温导致叶绿素、核酮糖-1,5-二磷酸羧化酶活性和蛋白质含量下降，葡萄糖含量增加，淀粉含量减少。此外，二氧化碳浓度升高诱导了几个参与线粒体电子传递的基因、一些光合作用和果聚糖合成相关基因，以及大多数参与次生代谢、赤霉素和茉莉酸代谢的基因，而那些与光捕获、氮同化和其他激素途径相关的基因受到抑制。高温抑制了碳、能量、氮、脂质、次生和激素代谢相关基因。在大气二氧化碳浓度和温度共同升高的情况下，转录谱与之前报道的高温情况相似，尽管二氧化碳浓度升高部分缓解了初级和次级代谢基因的下调。结果表明，在未来气候情景下，初级和次级代谢发生了重新编程，导致在二氧化碳浓度升高时碳氮代谢协调调节向富含碳的代谢物转变，而在高温时则远离富含碳的次生代谢物。鉴定出了几个差异表达的候选基因，包括蛋白激酶、受体激酶和转录因子。
