Affiliation:
1. Center for Agricultural Water Research in China China Agricultural University Beijing China
2. National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province Wuwei China
3. College of Plant Science and Technology Huazhong Agricultural University Wuhan China
4. Research Group in Plant Biology under Mediterranean Conditions Universitat de les Illes Balears Palma Spain
Abstract
AbstractThe plasticity of the xylem and its associated hydraulic properties play crucial roles in plant acclimation to environmental changes, with vessel diameter (Dv) being the most functionally prominent trait. While the effects of external environmental factors on xylem formation and Dv are not fully understood, the endogenous hormones indole‐3‐acetic acid (IAA) and abscisic acid (ABA) are known to play significant signalling roles under stress conditions. This study investigates how these hormones impact Dv under various environmental changes. Experiments were conducted in maize plants subjected to drought, soil salinity, and high CO2 concentration treatments. We found that drought and soil salinity significantly reduced Dv at the same stem internode, while an elevated CO2 concentration can mitigate this decrease in Dv. Remarkably, significant negative correlations were observed between Dv and the contents of IAA and ABA when considering the different treatments. Moreover, appropriate foliar application of either IAA or ABA on well‐watered and stressed plants led to a decrease in Dv, while the application of corresponding inhibitors resulted in an increase in Dv. This finding underscores the causal relationship between Dv and the levels of both IAA and ABA, offering a promising approach to manipulating xylem vessel size.
Funder
National Natural Science Foundation of China