Yu Jingjin, Li Ran, Fan Ningli, Yang Zhimin, Huang Bingru
College of Agro-grassland Science, Nanjing Agricultural UniversityNanjing, China.
Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New BrunswickNJ, United States.
Front Plant Sci. 2017 Sep 19;8:1506. doi: 10.3389/fpls.2017.01506. eCollection 2017.
Global climate changes involve elevated temperature and CO concentration, imposing significant impact on plant growth of various plant species. Elevated temperature exacerbates heat damages, but elevated CO has positive effects on promoting plant growth and heat tolerance. The objective of this study was to identify metabolic pathways affected by elevated CO conferring the improvement of heat tolerance in a C perennial grass species, bermudagrass ( Pers.). Plants were planted under either ambient CO concentration (400 μmol⋅mol) or elevated CO concentration (800 μmol⋅mol) and subjected to ambient temperature (30/25°C, day/night) or heat stress (45/40°C, day/night). Elevated CO concentration suppressed heat-induced damages and improved heat tolerance in bermudagrass. The enhanced heat tolerance under elevated CO was attributed to some important metabolic pathways during which proteins and metabolites were up-regulated, including light reaction (ATP synthase subunit and photosystem I reaction center subunit) and carbon fixation [(glyceraldehyde-3-phosphate dehydrogenase, GAPDH), fructose-bisphosphate aldolase, phosphoglycerate kinase, sedoheptulose-1,7-bisphosphatase and sugars) of photosynthesis, glycolysis (GAPDH, glucose, fructose, and galactose) and TCA cycle (pyruvic acid, malic acid and malate dehydrogenase) of respiration, amino acid metabolism (aspartic acid, methionine, threonine, isoleucine, lysine, valine, alanine, and isoleucine) as well as the GABA shunt (GABA, glutamic acid, alanine, proline and 5-oxoproline). The up-regulation of those metabolic processes by elevated CO could at least partially contribute to the improvement of heat tolerance in perennial grass species.
全球气候变化包括气温升高和二氧化碳浓度增加，对各种植物的生长产生重大影响。气温升高会加剧热害，但二氧化碳浓度升高对促进植物生长和耐热性有积极作用。本研究的目的是确定在一种C4多年生禾本科植物狗牙根（Cynodon dactylon (L.) Pers.）中，受二氧化碳浓度升高影响的代谢途径，这些途径有助于提高其耐热性。将植物种植在环境二氧化碳浓度（400 μmol⋅mol⁻¹）或升高的二氧化碳浓度（800 μmol⋅mol⁻¹）下，并置于环境温度（30/25°C，白天/夜晚）或热胁迫（45/40°C，白天/夜晚）条件下。升高的二氧化碳浓度抑制了狗牙根的热诱导损伤并提高了其耐热性。二氧化碳浓度升高时耐热性增强归因于一些重要的代谢途径，在此过程中蛋白质和代谢物被上调，包括光合作用的光反应（ATP合酶亚基和光系统I反应中心亚基）和碳固定[（甘油醛-3-磷酸脱氢酶，GAPDH）、果糖-1,6-二磷酸醛缩酶、磷酸甘油酸激酶、景天庚酮糖-1,7-二磷酸酶和糖类]、呼吸作用的糖酵解（GAPDH、葡萄糖、果糖和半乳糖）和三羧酸循环（丙酮酸、苹果酸和苹果酸脱氢酶）、氨基酸代谢（天冬氨酸、蛋氨酸、苏氨酸、异亮氨酸、赖氨酸、缬氨酸、丙氨酸和异亮氨酸）以及γ-氨基丁酸分流途径（γ-氨基丁酸、谷氨酸、丙氨酸、脯氨酸和5-氧代脯氨酸）。二氧化碳浓度升高对这些代谢过程的上调至少可以部分解释多年生禾本科植物耐热性的提高。
