1996/03/01 by Z. Tuba, Hartmut K. Lichtenthaler, Zs. Csintalan +2 · 4 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Environmental Science · #Photosynthetic Processes and Mechanisms #Plant Water Relations and Carbon Dynamics #Plant responses to elevated CO2
paper · doi:10.1111/j.1399-3054.1996.tb00448.x
openalex publication_date 1996/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
During a slow desiccation in photosynthetically fully active leaves of the poikilochlorophyllous desiccation‐tolerant (PDT) monocotyledon Xerophyta scabrida (Pax) Th. Dur. et Schinz (Velloziaceae), thylakoid activity, CO 2 assimilation and respiration decline and chlorophylls and carotenoids are successively broken down. The initially slow rate of leaf water loss is related to the large reduction in leaf area which is reflected in the decrease of specific leaf area. Chlorophylls are broken down faster than carotenoids. The ratio of the variable chlorophyll fluorescence, an indicator of photosynthetic activity (Rfd690‐values), shows that the functionality of thylakoids and chlorophylls is successively lost during desiccation. The decline in net CO 2 assimilation in desiccating leaves is largely caused by stomatal closure. The complete cessation of CO 2 assimilation, however, is due to the breakdown of chlorophylls and thylakoids. Respiration continued during desiccation and remained active far below ‐3.2 MPa leaf water potential. The differences during desiccation of the photosynthetic apparatus between poikilochlorophyllous and homoiochlorophyllous desiccation‐tolerant plants are discussed.