Back to Search
Start Over
Why is C4 photosynthesis so rare in trees?
- Source :
- Journal of Experimental Botany
- Publication Year :
- 2020
- Publisher :
- Oxford University Press, 2020.
-
Abstract
- We review possible physiological, anatomical, and evolutionary limitations that may explain the rarity of C4 photosynthesis in trees and discuss how the C4 trees in Euphorbia are exceptions to this.<br />Since C4 photosynthesis was first discovered >50 years ago, researchers have sought to understand how this complex trait evolved from the ancestral C3 photosynthetic machinery on >60 occasions. Despite its repeated emergence across the plant kingdom, C4 photosynthesis is notably rare in trees, with true C4 trees only existing in Euphorbia. Here we consider aspects of the C4 trait that could limit but not preclude the evolution of a C4 tree, including reduced quantum yield, increased energetic demand, reduced adaptive plasticity, evolutionary constraints, and a new theory that the passive symplastic phloem loading mechanism observed in trees, combined with difficulties in maintaining sugar and water transport over a long pathlength, could make C4 photosynthesis largely incompatible with the tree lifeform. We conclude that the transition to a tree habit within C4 lineages as well as the emergence of C4 photosynthesis within pre-existing trees would both face a series of challenges that together explain the global rarity of C4 photosynthesis in trees. The C4 trees in Euphorbia are therefore exceptional in how they have circumvented every potential barrier to the rare C4 tree lifeform.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Expert View
food.ingredient
C4 photosynthesis
Chamaesyce
Physiology
symplastic
Plant Science
Biology
phloem loading
Photosynthesis
01 natural sciences
Carbon Cycle
03 medical and health sciences
food
Euphorbia
Phloem loading
Water transport
Ecology
AcademicSubjects/SCI01210
Euphorbiaceae
trees
Plants
Biological Evolution
030104 developmental biology
Phenotype
disjunct veins
Trait
Habit (biology)
Tree (set theory)
quantum yield
010606 plant biology & botany
Subjects
Details
- Language :
- English
- ISSN :
- 14602431 and 00220957
- Volume :
- 71
- Issue :
- 16
- Database :
- OpenAIRE
- Journal :
- Journal of Experimental Botany
- Accession number :
- edsair.doi.dedup.....04ede79830e5f2e1cc0efd9cdaa8544d