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C 4 photosynthesis and transition of Kranz anatomy in cotyledons and leaves of Tetraena simplex.
- Source :
-
American journal of botany [Am J Bot] 2018 May; Vol. 105 (5), pp. 822-835. Date of Electronic Publication: 2018 May 23. - Publication Year :
- 2018
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Abstract
- Premise of the Study: Tetraena simplex is an independently evolved C <subscript>4</subscript> species in the Zygophylloideae (Zygophyllaceae) and a characteristic forb of saline flats in hot and sandy desert habitats. During early ontogeny, the species had a morphological shift from planar cotyledons (dorsiventral symmetry) to terete, succulent leaves (radial symmetry). We tested whether this shift had a corresponding change in internal Kranz anatomy and tissue patterning.<br />Methods: For a comprehensive characterization of C <subscript>4</subscript> photosynthesis across early ontogeny in T. simplex, structural and ultrastructural anatomical properties and localization patterns, activities, and immunoblotting of key C <subscript>4</subscript> photosynthetic enzymes were compared in mesophyll and bundle sheath tissues in cotyledons and leaves.<br />Key Results: Cotyledons and leaves possessed different types of Kranz anatomy (atriplicoid type and a "Tetraena" variant of the kochioid type, respectively), reflecting the change in leaf morphology. In bundle sheath cells, key differences in ultrastructural features included increased organelle numbers and chloroplast thylakoid stacking. C <subscript>4</subscript> enzymes had strict tissue-specific localization patterns within bundle sheath and mesophyll cells in both cotyledons and leaves. The decarboxylase NAD-ME maintained the highest activity, increasing from cotyledons to leaves. This classified T. simplex as fully C <subscript>4</subscript> across ontogeny and a strictly NAD-ME biochemical subtype.<br />Conclusions: Tetraena simplex cotyledons and leaves showed differences in Kranz type, with associated progression in ultrastructural features, and differing activities/expression levels of C <subscript>4</subscript> enzymes. Furthermore, leaves characterized a new "Tetraena" variation of the kochioid Kranz anatomy.<br /> (© 2018 Botanical Society of America.)
- Subjects :
- Carbon metabolism
Cotyledon anatomy & histology
Cotyledon enzymology
Cotyledon metabolism
Cotyledon ultrastructure
Plant Leaves anatomy & histology
Plant Leaves enzymology
Plant Leaves metabolism
Plant Leaves ultrastructure
Zygophyllaceae enzymology
Zygophyllaceae ultrastructure
Carbon chemistry
Carbon Cycle
Photosynthesis
Zygophyllaceae anatomy & histology
Zygophyllaceae metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1537-2197
- Volume :
- 105
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- American journal of botany
- Publication Type :
- Academic Journal
- Accession number :
- 29791720
- Full Text :
- https://doi.org/10.1002/ajb2.1087