Roles of Light-Harvesting Complex Stress-Related Proteins in the Stress Responses of <i>Chlamydomonas</i>

Abstract

Light is very important for photosynthesis in plants. However, excess light can result in photodamage to the photosynthetic apparatus. Via nonphotochemical quenching (NPQ), the oxidative stress caused by excess light energy can be counteracted by photoprotective mechanisms that evolve photosynthetic/oxygenic organisms. Energy-dependent quenching (qE), as the major NPQ component, relies on the accumulation of specific proteins that are termed light-harvesting complex stress-related (LHCSR) proteins in microalgae and mosses. LHCSRs have been reported to participate in adaptation to diverse environmental stresses, including excess light. In this review, we discuss the identification of LHCSRs in <i>Chlamydomonas</i> and the basic biochemical properties and functions of LHCSRs in acclimation to environmental stresses such as excess light and salt stress. We further review the potential interactive factors and upstream regulators of LHCSRs in <i>Chlamydomonas</i>, aiming to explore the underlying mechanism of <i>LHCSRs </i>in adaptation to multiple environmental stresses. We also discuss the evolution of LHCSRs in green algae and mosses and tentatively speculate about their participation in the adaptation to environmental change of the Earth. Work on <i>Chlamydomonas</i> LHCSR could provide clues to analyze the roles of LHCSR in both green algae and mosses. Thus, we offer an overview of current knowledge on the characteristics and functions of <i>Chlamydomonas</i> LHCSRs, which could shed new light on their detailed studies in both green algae and moss in the future.