EN
The chlorinal-1 (ch1-1) mutant of Arabidopsis thaliana lacks the light-harvesting complexes in photosystem II (LHCII) due to deficiency of ability to synthesize chlorophyll (Chl) b. To investigate if a lack of LHCII affects plant growth and water loss, the Chl content, Chl fluorescence, glutathione (GSH) content, plant growth, water loss and stomatal aperture were measured using wild-type (WT) and ch1-1 mutant plants. The leaves of ch1-1 mutants accumulated significantly lower Chl content, Chl fluorescence and GSH content than WT plants. Plant growth and the leaf area of ch1-1 plants were also lower when compared to WT plants. The ch1-1 plant showed delayed flowering and higher a number of rosette leaves compared to the WT plants. The treatment of N-acetylcysteine increased Chl content and Chl fluorescence in leaves of both plants. Stomatal aperture was significantly lower in guard cells of the ch1-1 mutant than that of WT plants. Dark treatment increased stomatal closure which was corrected followed by the light treatment. Abscisic acid (ABA)-induced stomatal aperture was significantly lower in ch1-1 mutant than WT plants. Water loss through stomatal opening in ch1-1 plants was significantly lower than WT plants regardless of ABA treatment. This study suggests that a lack of LHCII might control plant growth and water loss in ch1-1 mutant of Arabidopsis thaliana.