Non-foliar stomatal function in Glycine max
Disciplines
Agriculture | Biology
Abstract (300 words maximum)
Understanding how non-foliar tissues contribute to plant gas exchange can reveal hidden opportunities for improving water-use efficiency in crops. This study investigated the presence and function of stomata on foliar and non-foliar tissue, specifically leaf and pods, of Glycine max (soybean). The purpose was to determine whether pod stomata are structurally present, physiologically-active, and if they influence overall water loss and photosynthetic capacity in comparison to leaf stomata. This would be achieved by comparing wild-type soybean plants with variant soybean EPF2 plants, in which the epidermal patterning factor 2 gene results in the over-production of stomata. Microscopy was used to characterize stomatal density and size on both the leaf (adaxial and abaxial) and pod surfaces in wild-type and EPF2 over-expressing soybeans. Stomatal conductance (gₛ), chlorophyll fluorescence (ΦPSII), and gas exchange were measured with LI-600 and LI-6400 systems under well-watered and droughted conditions. Our study demonstrated that pods contained fewer but larger stomata than leaves, with abaxial leaf surfaces possessing the highest amount of stomata, in comparison to adaxial leaf surfaces and pod surfaces. Pod stomata were functionally active, with conductance and CO₂ assimilation increasing with light intensity. Droughted tissues showed lower gₛ and higher temperatures, reflecting reduced cooling and photosynthetic efficiency. Pod gas exchange showed a negative assimilation rate, but positive stomatal conductance. Thus, pods were found to be respirating more than photosynthesizing, which could impact crop yield. Further studies of variants that produce less pods and examination of water conservation could provide more insight into crop yield potential.
Use of AI Disclaimer
no
Academic department under which the project should be listed
CSM – Molecular and Cellular Biology
Primary Investigator (PI) Name
Tracy Lawson
Non-foliar stomatal function in Glycine max
Understanding how non-foliar tissues contribute to plant gas exchange can reveal hidden opportunities for improving water-use efficiency in crops. This study investigated the presence and function of stomata on foliar and non-foliar tissue, specifically leaf and pods, of Glycine max (soybean). The purpose was to determine whether pod stomata are structurally present, physiologically-active, and if they influence overall water loss and photosynthetic capacity in comparison to leaf stomata. This would be achieved by comparing wild-type soybean plants with variant soybean EPF2 plants, in which the epidermal patterning factor 2 gene results in the over-production of stomata. Microscopy was used to characterize stomatal density and size on both the leaf (adaxial and abaxial) and pod surfaces in wild-type and EPF2 over-expressing soybeans. Stomatal conductance (gₛ), chlorophyll fluorescence (ΦPSII), and gas exchange were measured with LI-600 and LI-6400 systems under well-watered and droughted conditions. Our study demonstrated that pods contained fewer but larger stomata than leaves, with abaxial leaf surfaces possessing the highest amount of stomata, in comparison to adaxial leaf surfaces and pod surfaces. Pod stomata were functionally active, with conductance and CO₂ assimilation increasing with light intensity. Droughted tissues showed lower gₛ and higher temperatures, reflecting reduced cooling and photosynthetic efficiency. Pod gas exchange showed a negative assimilation rate, but positive stomatal conductance. Thus, pods were found to be respirating more than photosynthesizing, which could impact crop yield. Further studies of variants that produce less pods and examination of water conservation could provide more insight into crop yield potential.