The photoinhibition of photosystem II in vivo by analysis of diverse components -initial rate, steady state rate and lag phase-of photosynthetic O_2 evolution curves on greening wheat seedlings after illumination by excess white light (320 W/m^2) was investigated. A sharp reduction in the initial and steady state rates and a simultaneous intense rise in the lag phase of O_2 evolution were observed under the illumination of seedlings by excess light on the lag phase of chlorophyll a biosynthesis (less than 6 h of seedling greening) in comparison with the illumination of seedlings by excess light at the stage of substantial pigment synthesis ( > 6 h of seedling greening). It is assumed that photosystem II proteins not completely integrated in thylakoid membranes as chlorophyll-protein complexes of reaction centres at the early stage of wheat seedling greening were more susceptible to excess light.
Wheat seedlings, O_2 evolution, photoinhibition, photosystem II
MAHMUDOV, ZAMAN MAHMUD; ABDULLAYEV, KHANLAR DAYYAN; and GASANOV, RALPHREED AHAD (2005) "Photoinhibition of Photosystem II In Vivo During Greening of the Wheat Seedlings," Turkish Journal of Botany: Vol. 29: No. 2, Article 2. Available at: https://journals.tubitak.gov.tr/botany/vol29/iss2/2