Leaf anatomy of c(3)-c(4) species as related to evolution of c(4) photosynthesis
1Department of Agronomy, University of Georgia, Athens, Georgia 30602.
Abstract:
This study was undertaken to examine the degree of Kranz anatomy development in the species intermediate to C(3) and C(4) types (C(3)-C(4)) in Panicum, Neurachne, Flaveria, and Moricandia. In each genus, C(3) and/or C(4) species were used for comparison. Leaf transections from each species were examined by light and transmission electron microscopy. The percentages of leaf photosynthetic cell profiles partitioned to bundle sheaths were higher in C(4) than in C(3) species, while C(3)-C(4) species tended to be in between. However, percentages for C(3)-C(4) species in Moricandia and some C(3)-C(4)Flaveria species were not greater than C(3). When expressed on a cell profile area basis, C(3)-C(4) species partitioned more photosynthetic tissue to bundle sheaths than C(3) species in Moricandia, but not in Flaveria. Neurachne minor S. T. Blake (C(3)-C(4)) partitioned a very small portion of cell profile area to the inner bundle sheaths (5%) compared to Neurachne munroi F. Muell (C(4)) (21%). The percentage of organelles partitioned to bundle sheaths was much greater in C(3)-C(4) than in C(3) species. The average C(3) percentages for mitochondria plus peroxisomes were 19, 8, and 19.5% for Neurachne, Flaveria, and Moricandia, respectively, compared to 41, 29, and 46.5% for the C(3)-C(4) species. The CO(2) compensation concentration was negatively related to the partitioning of tissue to bundle sheaths and to the percentage of organelles in bundle sheaths. It is concluded that all of the C(3)-C(4) species examined have developed some degree of Kranz anatomy and that this altered anatomy is involved in their reduced apparent photorespiration.
More Related Videos
11:49Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature
Published on: April 5, 2013
10:14Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area
Published on: October 25, 2024
Related Concept Videos
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
The Anatomy of Chloroplasts
Structure of Chloroplasts
A...
Anatomy of Chloroplasts
Light Acquisition
Basic Plant Anatomy: Roots, Stems, and Leaves
Introduction to Plant Diversity
