Genotypic variation in Metaxylem Vessel Element Length and Perforation Plate Height in maize
Authors
Christopher F. Strock, Cody L. DePew, Jagdeep S. Sidhu, Tianyu Xu, Jonathan P. Lynch
Source
Crop Science, 30 April 2026
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Open Access from Crop Science
Abstract
Core Ideas
- Metaxylem vessel element length (MVEL) varies substantially in maize genotypes.
- MVEL is correlated with reduced xylem perforation plate height, increased total vessel length, and increased axial hydraulic conductance.
- MVEL is positively correlated with root elongation, root depth, and deep water extraction in mesocosms.
- Under drought stress in the field, MVEL is associated with reduced leaf roll, reduced leaf temperature, greater transpiration, greater photosynthesis, and greater grain yield.
- MVEL is part of a pleiotropic ‘stretch phenotype’ that affects adaptation to water deficit.
Abstract
We tested the hypothesis that metaxylem phenotypes influence drought adaptation in maize (Zea mays L.) through in silico modeling and empirical studies under water deficit in controlled environments and in the field. Substantial genotypic variation for metaxylem vessel element length (MVEL) was observed. Longer MVEL was correlated with reduced xylem perforation plate height, greater vessel length, and greater axial hydraulic conductance in silico, which was supported by in situ measurements of root segments. GWAS revealed two different significant SNPs associated with MVEL and perforation plate height. Longer MVEL was correlated with greater root elongation, root depth, and deep water utilization in mesocosms. Under drought stress in the field, MVEL was associated with leaf roll, leaf temperature, transpiration, photosynthesis, and grain yield. We conclude that variation for MVEL in maize affects axial hydraulic conductance and is part of a pleiotropic syndrome we term the 'stretch phenotype' with greater root elongation and deeper rooting that improves adaptation to water deficit stress.
