A suberized exodermis is required for tomato drought tolerance

Area of Science:

• Plant Biology
• Molecular Biology
• Plant Physiology

Background:

• Plant roots develop apoplastic diffusion barriers, like suberin, crucial for regulating water, solute, and gas flow.
• Suberin deposition is typically associated with endodermal cell differentiation in plants.
• Tomato endodermis lacks suberin, but it is present in the exodermis, a cell type absent in Arabidopsis thaliana.

Purpose of the Study:

• To investigate the suberin regulatory network in tomato exodermis compared to Arabidopsis endodermis.
• To understand the genetic basis and functional significance of exodermal suberin in tomato.

Main Methods:

• Comparative analysis of suberin regulatory network components in tomato and Arabidopsis.
• Functional genetic analysis of key genes, including tomato MYB92 transcription factor and ASFT enzyme.
• Investigating the role of exodermal suberin in plant water-deficit response.

Main Results:

• The suberin regulatory network shares components between tomato exodermis and Arabidopsis endodermis.
• The network exhibits rewiring, leading to distinct spatial expression patterns and gene contributions.
• Exodermal suberin is vital for tomato's water-deficit response, functionally replacing the endodermal barrier.

Conclusions:

• The conserved suberin network is rewired in tomato to drive exodermal suberization.
• Exodermal suberin provides a functional equivalent to the endodermal barrier, crucial for water management.
• This highlights the plasticity of plant developmental networks in adapting to environmental cues.