An assessment of the capacity for phosphoenolpyruvate carboxykinase to contribute to C-4 photosynthesis

作者：Koteyeva Nuria K; Voznesenskaya Elena V; Edwards Gerald E^*

来源：Plant Science, 2015, 235: 70-80.

DOI：10.1016/j.plantsci.2015.03.004

• C-4 grasses
• C-4 eudicots
• C-4 photosynthesis
• NADP-ME type
• NAD-ME type
• PEPCK type

Three C-4 acid decarboxylases, phosphoenolpyruvate carboxykinase (PEPCK), NADP-malic enzyme (NADP-ME), and NAD-malic enzyme (NAD-ME) were recruited from C-3 plants to support C-4 photosynthesis. In Poaceae, there are established lineages having PEPCK type species, and some NADP-ME lineages in which PEPCK contributes to C-4. Besides family Poaceae, recently PEPCK has been reported to function in C-4 photosynthesis in eudicot species including Cleome gynandra (Cleomaceae), Trianthema portulacastrum and Zaleya pentandra (Aizoaceae). We evaluated PEPCK by enzyme assay and western blots in representatives of Poaceae, Aizoaceae, Cleomaceae, and Chenopodiaceae compared to that in the PEPCK type C-4 grass Spartina anglica. Eragrostis nutans was identified as the first NAD-ME type C-4 grass having substantial amounts of PEPCK. In the eudicots, including C gynandra, Cleome angustifolia, T. portulacastrum, pentandra, and nine C-4 members of family Chenopodiaceae (which has the most C-4 species and diversity in forms among eudicot families), amounts of PEPCK were generally very low (barely detectable up to 4% of that in S. anglica). Based on these results, C-4 species can be classified biochemically according to the dominant decarboxylase recruited for C-4 function; and, Poaceae remains the only family in which PEPCK is known to have a significant role in C-4 photosynthesis. Published by Elsevier Ireland Ltd.

• 出版日期2015-6