Journal
JOURNAL OF EXPERIMENTAL BOTANY
Volume 63, Issue 18, Pages 6481-6491Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jxb/ers303
Keywords
Cavitation; hydraulic conductivity; phenotypic plasticity; vessels; wood density; xylem embolism
Categories
Funding
- Alberta Ingenuity New Faculty Award
- Canada Research Chair Program
- Canada Foundation for Innovation
Ask authors/readers for more resources
Variation in xylem structure and function has been extensively studied across different species with a wide taxonomic, geographical, and ecological coverage. In contrast, our understanding of how xylem of a single species can adjust to different growing condition remains limited. Here phenotypic and developmental plasticity in xylem traits of hybrid poplar (Populus trichocarpadeltoides) was studied. Clonally propagated saplings were grown under experimental drought, nitrogen fertilization, and shade for > 30 d. Xylem hydraulic and anatomical traits were subsequently examined in stem segments taken from two different vertical positions along the plant's main axis. The experimental treatments affected growth and development and induced changes in xylem phenotype. Across all treatments, the amount of leaf area supported by stem segments (A(L)) scaled linearly with stem native hydraulic conductivity (K-native), suggesting that the area of assimilating leaves is constrained by the xylem transport capacity. In turn, K-native was mainly driven by the size of xylem cross-sectional area (A(X)). Moreover, the structural and functional properties of xylem varied significantly. Vulnerability to cavitation, measured as the xylem pressure inducing 50% loss of conductivity (P50), ranged from 1.71MPa to 0.15MPa in saplings subjected to drought and nitrogen fertilization, respectively. Across all treatments and stem segment positions, P50 was tightly correlated with wood density. In contrast, no relationship between P50 and xylem-specific conductivity (K-S) was observed. The results of this study enhance our knowledge of plant hydraulic acclimation and provide insights into common trade-offs that exist in xylem structure and function.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available