loading page

Coordination of stomata and vein patterns with leaf width underpins water use efficiency in a C4 crop
  • +5
  • Ling Pan,
  • Barbara George-Jaeggli,
  • Andrew Borrell,
  • David Jordan,
  • Fiona Koller,
  • Yazen Al-Salman,
  • Oula Ghannoum,
  • Francisco Cano
Ling Pan
Western Sydney University Hawkesbury Institute for the Environment

Corresponding Author:[email protected]

Author Profile
Barbara George-Jaeggli
The University of Queensland
Author Profile
Andrew Borrell
The University of Queensland
Author Profile
David Jordan
The University of Queensland
Author Profile
Fiona Koller
Western Sydney University Hawkesbury Institute for the Environment
Author Profile
Yazen Al-Salman
Western Sydney University Hawkesbury Institute for the Environment
Author Profile
Oula Ghannoum
Western Sydney University Hawkesbury Institute for the Environment
Author Profile
Francisco Cano
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria
Author Profile

Abstract

Despite its importance for crop productivity in drought-affected environments, the underlying mechanisms of variation in intrinsic water use efficiency (iWUE) are not well understood, especially in C4 plants. Recently, Cano et al. (2019) discovered that leaf width (LW) correlated negatively with iWUE and positively with stomatal conductance for water vapour (gsw) across several C4 grasses. Here, we analysed these relationships within 48 field-grown genotypes that cover a broad range of variation in LW in Sorghum bicolor, a well-adapted C4 crop to xeric and hot conditions, by measuring and modelling leaf gas exchange and leaf energy balance three times a day, using anatomical traits as potential drivers for iWUE. LW correlated negatively with iWUE and stomatal density, but positively with gsw, interveinal distance of longitudinal veins (IVDL) and the percentage of stomatal aperture relative to maximum. Energy balance modelling showed that wider leaves opened the stomata more to generate a more negative leaf-to-air temperature difference especially at midday, when air temperatures exceeded 40ºC. These results highlight the important role that LW plays in shaping iWUE through modification of vein and stomatal traits and by regulating stomatal aperture. Therefore, LW could be used as a predictor for higher iWUE among sorghum genotypes.
28 Nov 2021Published in Plant, Cell & Environment. 10.1111/pce.14225