Physiological and morphological acclimation to height in cupressoid leaves of 100-year-old Chamaecyparis obtusa
| Autor: | Wakana Azuma, H. Roaki Ishii, Ayumi Shiraki, Keiko Kuroda |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
Water transport biology Physiology Acclimatization Altitude Water stress fungi Xylem food and beverages Plant Science Photosynthesis biology.organism_classification 010603 evolutionary biology 01 natural sciences Hydraulic conductance Trees Plant Leaves Horticulture Chamaecyparis Interception 010606 plant biology & botany |
| Zdroj: | Tree Physiology. 37(10):1327 |
| ISSN: | 0829-318X |
| Popis: | Cupressoid (scale-like) leaves are morphologically and functionally intermediate between stems and leaves. While past studies on height acclimation of cupressoid leaves have focused on acclimation to the vertical light gradient, the relationship between morphology and hydraulic function remains unexplored. Here, we compared physiological and morphological characteristics between treetop and lower-crown leaves of 100-year-old Chamaecyparis obtusa Endl. trees (~27 m tall) to investigate whether height-acclimation compensates for hydraulic constraints. We found that physiological acclimation of leaves was determined by light, which drove the vertical gradient of evaporative demand, while leaf morphology and anatomy were determined by height. Compared with lower-crown leaves, treetop leaves were physiologically acclimated to water stress. Leaf hydraulic conductance was not affected by height, and this contributed to higher photosynthetic rates of treetop leaves. Treetop leaves had higher leaf area density and greater leaf mass per area, which increase light interception but could also decrease hydraulic efficiency. We inferred that transfusion tissue flanking the leaf vein, which was more developed in the treetop leaves, contributes to water-stress acclimation and maintenance of leaf hydraulic conductance by facilitating osmotic adjustment of leaf water potential and efficient water transport from xylem to mesophyll. Our findings may represent anatomical adaptation that compensates for hydraulic constraints on physiological function with increasing height. |
| Databáze: | OpenAIRE |
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