J Integr Plant Biol. ›› 1990, Vol. 32 ›› Issue (10): -.

• Research Articles •    

The Identification of Photosynthetic Subpathways of Some C4 and CAM Plants

Lin Zhi-fang,Sun Gu-chou, Li Shuang-shun, Lin Gui-zhu and Guo Jun-yan   

Abstract: The photosynthetic subpathways of five C4 plants and one CAM plant were distinguished according to their chemical, physiological and cytological characteristics. Based on C4 acid decarboxylation enzymes, four C4 plants of Setaria glauca, Sporobolus indicus, Zoysia tenuifolia and Leptochloa chinensis all exhibited the functional high activities of PEP carboxykinase and aspartate aminotransferase as seen in the known PEP-CK subtype. The δ13C value of –12.43% in leaves of L. chinensis was also consistent with that range among PEP-CK subtype. So, these species were classified into PEP-CK subtype. However, their chloroplasts in bundle sheath cells were evenly distributed, not as that displayed centrifugally or centripetally in three typical subtypes. The even arrangement of chloroplasts in bundle sheath cells was likely to be an evolutional intermediate from centripetal (NAD ME type) to centrifugal types (NADP-ME and most PEP-CK types). The high activities of NAD-malic enzyme and aspartate aminotransferase, accompanied with the centripetally located chloroplasts, 0.057 of quantum yield and tile δ13C value of –15.3% in leaves of C4 dicot Euphobia hirta indicated characteristics of NAD-ME subtype. Moreover, CAM plant Aloe vera clearly fell into PEP-CK sybtype because of its high activity of PEP-CK both in whole leaf and green tissue.

Key words: Photosynthetic subpathway, PEP carboxykinase, C4 plants, CAM plant

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2022 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q