Browsing by Subject "Guard cells"

Now showing 1 - 2 of 2

Guard cell‐specific metabolic responses to drought stress in maize
(2025) Lehr, Patrick Pascal; Erban, Alexander; Hartwig, Roman Paul; Wimmer, Monika Andrea; Kopka, Joachim; Zörb, Christian
Understanding crop responses to drought stress is crucial for securing future agricultural productivity. Guard cells regulate transpiration and thus the yield burden under drought conditions. Therefore, the influence of repeated drought stress on the guard cell metabolome of Zea mays L. was investigated to improve our understanding of crop resilience mechanisms. A controlled greenhouse experiment with physiological evaluation and a non‐targeted metabolomics approach was used to analyse unprimed and primed guard cells. Primed and unprimed maize plants showed similar overall physiological and metabolic responses to drought, with gas exchange and general metabolic patterns largely unaffected by priming. However, distinct priming effects emerged in specific metabolites. Metabolites of the alanine and aspartate pathway, as well as those of the glycine, serine and threonine pathway were less impacted by drought stress in guard cells than in mesophyll cells, suggesting the emphasis of plants to maintain stable guard cell metabolomes for functional integrity. In contrast, the increase in sugar concentrations in guard cells was similar to that in mesophyll cells, suggesting a pivotal role of sugars in guard cells during drought conditions. New insights into cell type‐specific metabolic responses to drought stress will contribute to a better understanding of stress memory in maize. Enhancing guard cell resilience could help optimise water use efficiency for sustainable agricultural production under climate change conditions.
Sulfate enhances metabolic acclimation under drought stress - a comparative study of grapevine and maize
(2025) Lehr, Patrick Pascal; Erban, Alexander; Kopka, Joachim; Zörb, Christian
The importance of sulfate fertilization in plant production has becoming increasingly relevant due to the decline in atmospheric sulfur inputs. Moreover, high-intensity cropping systems are increasingly facing drought scenarios. The role of stomata is crucial during drought stress and is linked to sulfate metabolism. This study investigates the impact of sulfate application on the drought response of grapevine and maize guard cells. Both plant species may serve as crop model for analysing underlying physiological processes in a low fertilizer demanding crop such as grapevine and a high fertilizer demanding crop such as maize. Increased sulfate concentration in leaves was triggered by drought in maize and grapevine, but in grapevine only when additional sulfate was applied. Additional sulfate application improved sulfur availability under drought conditions, which enhanced drought stress response in grapevine and maize. This was characterized by enhanced metabolic acclimation under drought conditions. The effect of sulfate on the drought stress response was markedly diminished in guard cells, indicating enhanced metabolic stability of guard cells against external influences. These results underscore the significance of adequate sulfate supply to crops for optimal drought stress response and suggest that sulfate fertilisation may serve as a potential option to enhance drought acclimation