Phosphorylation State of the Light-Harvesting Chlorophyll-Protein Complex of Photosystem II and Chlorophyll Fluorescence Characteristics in Monstera deliciosa Liebm. And Glycine max (L.) Merrill in Response to Light

Abstract

Upon a transition from darkness to (low) light, leaves of the rainforest plant Monstera deliciosa which had developed in deep shade exhibited a decline in PS II chlorophyll fluorescence (F_O and F_M) and a net increase in PS I fluorescence (F_O and F_M) indicative of a state transition. Upon this transition, LHC-II became phosphorylated. Phosphorylation of LHC-II was maintained upon exposure of M. deliciosa leaves to photon flux densities (PFDs) representing an excess of light, independent of whether the excess of light was created by exposing the leaves to high PFDs in air (where photosynthesis and photorespiration can proceed) or by exposing them to intermediate PFDs in 2% O₂ without CO₂ (where photosynthesis and photorespiration are prevented). This was in contrast to the response of soybean leaves, in which LHC-II became dephosphorylated under both of these conditions representing an excess of light. These different response patterns may be associated with a heterogeneity of LHC-II populations and/or differences in the expression of energy dissipation in the chlorophyll pigment bed between the two types of leaves.