caa a22 4500 60548080X CHVBK 20210128100417.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s11099-015-0130-5 doi (NATIONALLICENCE)springer-10.1007/s11099-015-0130-5 Effect of high light intensity on photoinhibition, oxyradicals and artemisinin content in Artemisia annua L [Elektronische Daten] [M. Poulson, T. Thai] Artemisia annua L. produces a compound called artemisinin that is a potent anti-malarial compound. However concentration of artemisinin within the plant is typically low (less than 0.8% of dry mass) and currently supply of the drug by the plant does not meet world demand. This investigation was carried out to determine whether high intensity light treatment would increase production of artemisinin in leaves of A. annua. Photoinhibition (14%) was induced in leaves of A. annua when they were subjected to 6 h of high-intensity light [2,000 μmol(photon) m-2 s−1]. Maximum photochemical efficiency of PSII showed a recovery of up to 95% within 24 h of light induced inhibition. During the light treatment, photochemical efficiency of PSII in leaves of the high-intensity light-treated plants was 38% lower than for those from leaves of plants subjected to a low-intensity-light treatment of 100 μmol(photon) m-2 s−1. Nonphotochemical quenching of excess excitation energy was 2.7 times higher for leaves treated with high-intensity light than for those irradiated with low-intensity light. Elevation in oxidative stress in irradiated leaves increased presence of reactive oxygen species (ROS) including singlet oxygen, superoxide anions, and hydrogen peroxide. Importantly, the concentration of artemisinin in leaves was two-fold higher for leaves treated with high-intensity light, as compared to those treated with low-intensity light. These results indicate that A. annua responds to high irradiance through nonphotochemical dissipation of light energy yet is subject to photoinhibitory loss of photosynthetic capacity. It can be concluded that A. annua is capable of rapid recovery from photoinhibition caused by high light intensity. High light intensity also induced oxidative stress characterized by increased concentration of ROS which enhanced the content of artemisinin. Such a light treatment may be useful for the purpose of increasing artemisinin content in A. annua prior to harvest. The Institute of Experimental Botany, 2015 chlorophyll fluorescence nationallicence environmental stress nationallicence irradiation nationallicence ACT : artemisinin-based combination therapy nationallicence APX : ascorbate peroxidase nationallicence FM : fresh mass nationallicence Fm : maximal fluorescence yield of the dark-adapted state nationallicence Fm′ : maximal fluorescence yield of the light-adapted state nationallicence Fs : steady-state fluorescence yield nationallicence Fv : variable fluorescence nationallicence Fv/Fm : maximal quantum yield of PSII photochemistry nationallicence HPLC : high pressure liquid chromatography nationallicence NPQ : nonphotochemical quenching of PSII nationallicence ROS : reactive oxygen species nationallicence qP : photochemical quenching coefficient nationallicence SD : standard deviation nationallicence UV-B : ultraviolet-B nationallicence UV-C : ultraviolet-C nationallicence ΦPSII : quantum efficiency of PSII nationallicence WHO : World Health Organization nationallicence Poulson M. Department of Biological Sciences, Central Washington University, 98926-7530, Ellensburg, WA, USA aut Thai T. Department of Biological Sciences, Central Washington University, 98926-7530, Ellensburg, WA, USA aut Photosynthetica The Institute of Experimental Biology of the Czech Academy of Sciences 53/3(2015-09-01), 403-409 0300-3604 53:3<403 2015 53 11099 https://doi.org/10.1007/s11099-015-0130-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11099-015-0130-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Poulson M. Department of Biological Sciences, Central Washington University, 98926-7530, Ellensburg, WA, USA aut NATIONALLICENCE 700 1- Thai T. Department of Biological Sciences, Central Washington University, 98926-7530, Ellensburg, WA, USA aut NATIONALLICENCE 773 0- Photosynthetica The Institute of Experimental Biology of the Czech Academy of Sciences 53/3(2015-09-01), 403-409 0300-3604 53:3<403 2015 53 11099