Ajaya K Biswal, Gopal K Pattanayak, Kamal Ruhil, Deepika Kandoi, Sushree S Mohanty, Sadhu Leelavati, Vanga S Reddy, Govindjee Govindjee, Baishnab C Tripathy
UNLABELLED: Chlorophyll b is synthesized from chlorophyllide a , catalyzed by chlorophyllide a oxygenase ( CAO ). To examine whether reduced chlorophyll b content regulates chlorophyll (Chl) synthesis and photosynthesis, we raised CAO transgenic tobacco plants with antisense CAO expression, which had lower chlorophyll b content and, thus, higher Chl a / b ratio. Further, these plants had (i) lower chlorophyll b and total Chl content, whether they were grown under low or high light; (ii) decreased steady-state levels of chlorophyll biosynthetic intermediates, due, perhaps, to a feedback-controlled reduction in enzyme expressions/activities; (iii) reduced electron transport rates in their intact leaves, and reduced Photosystem (PS) I, PS II and whole chain electron transport activities in their isolated thylakoids; (iv) decreased carbon assimilation in plants grown under low or high light...
January 2024: Physiology and Molecular Biology of Plants: An International Journal of Functional Plant Biology