College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China.
Laoshan Laboratory, 1 Wenhai Road, Qingdao, 266237, China.
BMC Plant Biol. 2024 Feb 28;24(1):143. doi: 10.1186/s12870-024-04762-w.
Solar radiation is primarily composed of ultraviolet radiation (UVR, 200 - 400 nm) and photosynthetically active radiation (PAR, 400 - 700 nm). Ultraviolet-B (UVB) radiation accounts for only a small proportion of sunlight, and it is the primary cause of plant photodamage. The use of chlorofluorocarbons (CFCs) as refrigerants caused serious ozone depletion in the 1980s, and this had led to an increase in UVB. Although CFC emissions have significantly decreased in recent years, UVB radiation still remains at a high intensity. UVB radiation increase is an important factor that influences plant physiological processes. Ulva prolifera, a type of macroalga found in the intertidal zone, is intermittently exposed to UVB. Alternative oxidase (AOX) plays an important role in plants under stresses. This research examines the changes in AOX activity and the relationships among AOX, photosynthesis, and reactive oxygen species (ROS) homeostasis in U. prolifera under changes in UVB and photosynthetically active radiation (PAR).
UVB was the main component of solar radiation impacting the typical intertidal green macroalgae U. prolifera. AOX was found to be important during the process of photosynthesis optimization of U. prolifera due to a synergistic effect with non-photochemical quenching (NPQ) under UVB radiation. AOX and glycolate oxidase (GO) worked together to achieve NADPH homeostasis to achieve photosynthesis optimization under changes in PAR + UVB. The synergism of AOX with superoxide dismutase (SOD) and catalase (CAT) was important during the process of ROS homeostasis under PAR + UVB.
AOX plays an important role in the process of photosynthesis optimization and ROS homeostasis in U. prolifera under UVB radiation. This study provides further insights into the response of intertidal macroalgae to solar light changes.
太阳辐射主要由紫外线辐射（UVR，200-400nm）和光合有效辐射（PAR，400-700nm）组成。紫外线-B（UVB）辐射仅占阳光的一小部分，是植物光损伤的主要原因。20 世纪 80 年代，氯氟碳化合物（CFCs）作为制冷剂的使用导致了严重的臭氧消耗，这导致了 UVB 的增加。尽管近年来 CFC 的排放量显著减少，但 UVB 辐射仍保持在高强度水平。UVB 辐射增加是影响植物生理过程的一个重要因素。石莼，一种潮间带的大型藻类，间歇性地暴露在 UVB 下。交替氧化酶（AOX）在植物应对压力时起着重要作用。本研究考察了 UVB 和光合有效辐射（PAR）变化下 U. prolifera 中 AOX 活性的变化以及 AOX、光合作用和活性氧（ROS）稳态之间的关系。
UVB 是影响典型潮间带绿藻 U. prolifera 的太阳辐射的主要成分。由于在 UVB 辐射下与非光化学猝灭（NPQ）的协同作用，发现 AOX 在 U. prolifera 的光合作用优化过程中很重要。AOX 和甘醇酸氧化酶（GO）共同作用，以实现 NADPH 稳态，以在 PAR+UVB 变化下实现光合作用优化。在 PAR+UVB 下 ROS 稳态过程中，AOX 与超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的协同作用很重要。
AOX 在 UVB 辐射下 U. prolifera 的光合作用优化和 ROS 稳态过程中起着重要作用。本研究为潮间带大型藻类对太阳光照变化的响应提供了进一步的见解。
