Divergent Effects of Successive Drought and Flooding on Photosynthesis in Wheat and Barley

Strategic Insights -

New research from the University of Manchester reveals that climate change is causing an increase in extreme weather events, leading to challenges in food security. The study, published in Frontiers in Plant Science, investigates the response of cereals to successive water stresses, which often occur in real-world scenarios. The researchers compared the physiological responses of wheat and barley cultivars to cycles of drought and flooding and found that these species show different responses to each other. The study highlights the importance of understanding how plants respond to multiple stresses to improve crop resilience.

Key Takeaways:

  • The study found that climate change is leading to an increase in extreme weather events, including droughts and floods, which undermine food security.
  • The researchers compared the physiological responses of wheat and barley cultivars to cycles of drought and flooding and found that these species show different responses to each other.
  • The study demonstrated that successive stresses result in different responses to single stresses, with wheat showing significant declines in CO2 assimilation capacity by 41% and 31% in response to drought or flooding, respectively.
  • Barley, on the other hand, retained its photosynthetic capacity under drought or flooding stress, with 41% reduced shoot growth in response to drought.
  • The study also found that non-stomatal factors were induced in wheat under successive stress, resulting in reduced Photosystem II efficiency (62% and 49%) and chlorophyll content (35% and 47%).
  • The research concluded that sensitivity to a stress is increased by the exposure to a previous stress, with F-D stress having the largest effect, highlighting barley as the more robust cereal crop under fluctuating water conditions.

Statistics:

  • 41% decline in CO2 assimilation capacity in wheat in response to drought stress
  • 31% decline in CO2 assimilation capacity in wheat in response to flooding stress
  • 35% reduction in Photosystem II efficiency in wheat under D-F stress
  • 47% reduction in chlorophyll content in wheat under F-D stress
  • 41% reduced shoot growth in barley in response to drought stress
  • 62% and 49% reduction in Photosystem II efficiency in wheat under D-F and F-D stress, respectively
  • 35% and 47% reduction in chlorophyll content in wheat under D-F and F-D stress, respectively

Sources:

  • Divergent effects of successive drought and flooding on photosynthesis in wheat and barley. Frontiers in Plant Science, 2025,16. (Frontiers in Plant Science - http://journal.frontiersin.org/journal/plant-science)
  • NewsRx. New Plant Science Study Findings Have Been Reported from University of Manchester (Divergent effects of successive drought and flooding on photosynthesis in wheat and barley). Science Letter. September 12, 2025; p 466.