Abstract
Light-harvesting complexes (LHCs) control light-dependent energy transfer in photosystem II(PSII). In order to find out if defective LHCs affect plant growth, light-related parameters were compared between a chlorinal-1 mutant (ch1-1; defective LHCs) and wild-type (WT) plants of Arabidopsis thaliana. The aim of this study was to assess the effects of LHCs on light-related parameters on the growth of Arabidopsis plants. A JUNIORPAM fluorometer was used to measure the parameters such as coefficients of photochemical fluorescence quenching (qp and ql); parameters of non-photochemical quenching (qn and NPQ), the yield of non-regulated energy dissipation of PSII [Y(NO)], the value of the efficient quantum yield of PSII {Y(II)}, and yield of regulated energy dissipation of PSII {Y(NPQ)}. The ch1-1 mutant showed similar coefficient of photochemical quenching to the WT plants. On the other hand, a non-photochemical quenching, an efficient quantum yield of PSII, and yield of regulated energy dissipation of PSII significantly declined in ch1-1 mutant compared with the WT plants. The ch1-1 mutant plants exhibited the value of decreased growth and smaller size of leaf compared with that of WT plants. The percentage of the area, length and width of the leaf of the mutant declined when compared with that of WT plants. These results suggest that defective LHCs regulated growth through affecting light-related parameters of the ch1-1 mutant of Arabidopsis thaliana plants.