Utrecht University: 700.000 Euro grant for Rashmi Sasidharan

The question of how plants cope with floods becomes more relevant by the day, as climate change has increased the incidence of floods. Most major crops are extremely vulnerable to wet soils. To prevent severe crop losses in the future, biologists are trying to unravel what mechanisms plants use defend themselves against negative effects of flooding.

Suffocating plants
With this grant, Sasidharan’s team aims to unravel how plants endure low-oxygen conditions that occur during flooding. One of the primary reasons why plants are vulnerable to flooding is because the water ‘suffocates’ the plant. When flooded, plants have reduced access to CO2 and oxygen, which reduces photosynthesis and respiration.

The survival of the root is linked to the so-called meristem, a tiny cluster of cells in the root tip.
Prone to flooding
The researchers focus on plant roots, as this part is the most prone to flooding and the first to encounter oxygen deficiency. The survival of the root is linked to the so-called meristem, a tiny cluster of cells in the root tip. Once the flood waters retreat, the renewal of root systems, and thus the whole plant, depends on the meristem survival.

Focus on plant hormones
The team will specifically focus on the plant hormone ethylene, which is an early flood detection cue. When gas exchange is reduced during flooding, ethylene levels in roots rise rapidly, before oxygen deficiency kicks in. Earlier studies by Sasidharan and colleagues showed that rising ethylene levels enhance root survival, but exactly how this protection works remained unclear.

Manipulate and model stress responses
Within the granted project, the team will generate tools to manipulate and model stress responses of specific root cell types. “This is exciting because we can now zoom deeper into the plant root, and investigate how individual cell layers communicate to protect the meristem during stressful conditions”, said Sasidharan.

Ultimately, our aim is to generate climate-resilient ‘waterproof’ plants

Rashmi Sasidharan
Dr. Sashmi Sasidharan
Plant Ecophysiology
Despite its enormous relevance, flooding stress is a relatively understudied phenomenon in plant research, said Sasidharan. “This project will further our core mission of a fundamental understanding of plant flood resilience mechanisms. Ultimately, our aim is to generate climate-resilient ‘waterproof’ plants. Understanding the molecular mechanisms underlying tolerance to flooded conditions is extremely essential towards realizing this goal.”