Light occupies a central position in regulating development of plants. Either little or excess of light could be harmful for plants. Since bryophytes are shade loving organisms, they must adapt to function in fluctuating light regimes. Therefore, the aim of this study was to investigate acclimatory responses of Riccia discolor thalli grown under full sunlight, and were compared with shade grown thalli (control). Length, width, and fresh mass of thallus were significantly lower (by 27, 41 and 37%, respectively) but endogenous nitric oxide content (by 81%) and nitric oxide synthase like activity (by 58%) were higher in full sunlight grown thalli than shade grown thalli. Number of rhizoids was greater in shade but length and width of rhizoids were higher (by 36 and 25%, respectively) in full sunlight grown thalli. The content of carotenoids was higher (by 34%) in full sunlight grown thalli. In full sunlight grown thalli, chloroplasts exhibited avoidance movement but in shade grown thalli they exhibited accumulation movement. Photosynthetic yields were higher in shade grown thalli. Among energy fluxes, ABS/RC did not vary but DI₀/RC was higher (by 12%) in full sunlight grown thalli. Reactive oxygen species and damage were greater in full sunlight grown thalli despite enhanced levels of antioxidants i.e. superoxide dismutase (by 66%) and catalase (by 34%). Overall results suggest that full sunlight acclimation in Riccia discolor thalli occurred at various levels in which endogenous NO plays a positive role.

光线在调节植物发育中占据中心位置。很少或过多的光可能对植物有害。由于苔藓植物是喜欢遮阳的生物，因此它们必须适应波动的光照状态下的功能。因此，本研究的目的是研究变色丽卡氏菌的适应性反应。沙丘在充分的阳光下生长，并与阴暗的沙丘（对照）进行比较。在日光充足的条件下，th的长度，宽度和新鲜质量显着降低（分别降低了27％，41％和37％），但是内源性一氧化氮含量（降低了81％）和一氧化氮合酶样活性（提高了58％）塔利比树荫下生长的塔利。在充满阳光的沙丘中，阴影下的类根茎数量较多，但类根茎的长度和宽度较高（分别增加36％和25％）。在日光充足的thalli中，类胡萝卜素的含量较高（增加了34％）。在充满阳光的沙丘中，叶绿体表现出回避运动，而在荫凉的沙丘中，它们表现出积聚运动。遮荫生长的塔利的光合产量较高。在能量通量中，ABS / RC没有变化，但DI ₀在日光充足的塔利里，/ RC较高（提高了12％）。尽管抗氧化剂水平提高的活性氧物种和损害者更大全光照生长的菌体，即超氧化物歧化酶（由66％）和过氧化氢（34％）。总体结果表明，在变色里卡虫中，阳光完全适应了不同水平，其中内源性NO发挥了积极作用。