Analysis of chlorophyll fluorescence parameters in leaves of strigolactone mutants of Arabidopsis thaliana
摘要
Strigolactones are a class of carotenoid-derived compounds and play as novel signaling molecules to regulate various processes of growth and development in plant. For understanding the roles of strigolactone and its signaling protein in plant photosynthesis, we measured the contents of photosynthetic pigments and chlorophyll fluorescence parameters in the leaves of strigolactone biosynthesis mutant max1, strigolactone insensitive mutants max2 and wild type of Arabidopsis thaliana, and the results showed that features of photosynthetic fluorescence are obvious differences in max1 and max2 mutants. The contents of chlorophyll and values of photochemical-related parameters weren't significantly decreased in max1 mutant, but ratio of content of chlorophyll a to chlorophyll b was reduced and the value of minimal fluorescence (Fo) and Y (NO) were increased than WT plant. Furthermore, rapid light-response curve of PSⅡ chlorophyll fluorescence parameters showed that the value of electron transport rate through PSⅡ (ETR), Y (Ⅱ) and QNP in max1 mutant is lower than WT under intensive light. However, in max2 mutant, the contents of chlorophyll and values of photochemical-related parameters including maximum quantum efficiency of PSⅡ photochemistry (Fv/Fm), actual photochemical rate of PSⅡ[Y (Ⅱ)]and photochemical dissipation (qP) are significantly lower than WT (P < 0.05), while the values of photoprotection-related parameters, such as nonphotochemical quenching (QNP) and non-photochemical dissipation (qP), are significantly higher than WT (P < 0.05). These results demonstrated that strigolactone are possibly involved in modulating photosynthesis adaptability in response to environmental cues, and MAX2 protein has specific roles in plant photosystem and photosynthesis that different with strigolactone, which possibly participates in regulation of structure of photosystem of plant.