Recovery from Low Temperature Photoinhibition Is Not Governed by Changes in the Level of Zeaxanthin in Rice (Oryza sativa L.) Leaves

• Published in: Journal of plant physiology 1999-12, Vol.155 (6), p.755-761
• Main Authors: Xu, Chang Cheng, Lee, Hyo Peon, Lee, Choon-Hwan
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Chilling; Economic plant physiology; Fluorescence quenching; Fundamental and applied biological sciences. Psychology; Metabolism; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; Oryza sativa; Photoinhibition of photosynthesis; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; Xanthophyll cycle; Zeaxanthin epoxidation
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/S0176-1617(99)80093-5

The possible involvement of zeaxanthin (Z) in the recovery of photochemical efficiency of photosystem II (PSII) from chilling-induced photoinhibition in rice (Oryza sativa L. cv. Dongjin-byeo) leaves was investigated. During recovery at 20°C after chilling in moderate light, the increase in PSII efficiency was biphasic. The first phase of recovery was mainly due to the relaxation of the trans-thylakoid proton gradient. The following second phase was insensitive to nigericin and accompanied by a decrease in the level of Z. However, incubation with salicylaldoxime, an inhibitor of epoxidase, blocked Z epoxidation without any effect on PSII recovery. During recovery at 10°Q the amount of Z continued to decline after the PSII efficiency had reached a constant level corresponding to the first phase of recovery at 20°C. When leaves were allowed to recover at a photosynthetic photon flux higher than 30 εmol. m−2 · s−1, both the decrease in the content of Z and the increase in PSII efficiency were slowed down. However, dithiothreitol eliminated the retarding effect of light on the rate of Z decrease while exerting little effect on PSII recovery. In high light-chilled leaves, pretreatment with lincomycin blocked both the increase in PSII efficiency and the decrease in the level of Z during recovery in the light, but lincomycin only marginally affected the Z epoxidation during recovery in the dark. It is concluded that the recovery of PSII efficiency from low temperature photoinhibition is not mainly controlled by changes in the level of Z in rice leaves. The possible indirect links between Z epoxidation and PSII recovery from photoinhibition are discussed.