Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agriculture Sciences, Beijing, China.
Horticulture and Product Physiology, Department of Plant Sciences, Wageningen University, Wageningen, the Netherlands.
Plant Cell Environ. 2020 Sep;43(9):2192-2206. doi: 10.1111/pce.13810. Epub 2020 Jun 28.
In nature, soil salinity and fluctuating light (FL) often occur concomitantly. However, it is unknown whether salt stress interacts with FL on leaf photosynthesis, architecture, biochemistry, pigmentation, mineral concentrations, as well as whole-plant biomass. To elucidate this, tomato (Solanum lycopersicum) seedlings were grown under constant light (C, 200 μmol m s ) or FL (5-650 μmol m s ), in combination with no (0 mM NaCl) or moderate (80 mM NaCl) salinity, for 14 days, at identical photoperiods and daily light integrals. FL and salt stress had separate effects on leaf anatomy, biochemistry and photosynthetic capacity: FL reduced leaf thickness as well as nitrogen, chlorophyll and carotenoid contents per unit leaf area, but rarely affected steady-state and dynamic photosynthetic properties along with abundance of key proteins in the electron transport chain. Salt stress, meanwhile, mainly disorganized chloroplast grana stacking, reduced stomatal density, size and aperture as well as photosynthetic capacity. Plant biomass was affected interactively by light regime and salt stress: FL reduced biomass in salt stressed plants by 17%, but it did not affect biomass of non-stressed plants. Our results stress the importance of considering FL when inferring effects of salt-stress on photosynthesis and productivity under fluctuating light intensities.
在自然界中，土壤盐度和波动的光照（FL）通常同时发生。然而，目前尚不清楚盐胁迫是否会与 FL 相互作用，影响叶片光合作用、结构、生物化学、色素、矿物质浓度以及整株植物的生物量。为了阐明这一点，我们将番茄（Solanum lycopersicum）幼苗在恒定光照（C，200 μmol m s ）或 FL（5-650 μmol m s ）下生长 14 天，同时施加无（0 mM NaCl）或中度（80 mM NaCl）盐度，光照周期和每日光积分相同。FL 和盐胁迫对叶片解剖结构、生物化学和光合作用能力有单独的影响：FL 降低了叶片厚度以及单位叶面积的氮、叶绿素和类胡萝卜素含量，但很少影响稳态和动态光合作用特性以及电子传递链中的关键蛋白丰度。另一方面，盐胁迫主要扰乱叶绿体基粒堆叠，降低了气孔密度、大小和开度，以及光合作用能力。光照制度和盐胁迫对植物生物量的影响具有交互作用：FL 使盐胁迫下的植物生物量减少了 17%，但对非胁迫植物的生物量没有影响。我们的研究结果强调了在波动光照强度下推断盐胁迫对光合作用和生产力影响时，考虑 FL 的重要性。
