Miranda Haus

  • Feb 20, 2018

Date & Location: February 20, 2018, at 12p; Room 168 Plant Biology Building

Subject: Regulation of stomatal patterning by CO2 across Arabidopsis tissues occurs during spacing divisions

Abstract: Stomata control water loss and carbon dioxide uptake by both altering pore aperture and developmental patterning. Stomatal patterning is regulated by environmental factors including atmospheric carbon dioxide (p[CO2]), which is increasing globally at an unprecedented pace. Interestingly, mature leaves are known to convey developmental cues to immature leaves in response to p[CO2], but the developmental mechanisms are unknown.

To characterize changes in stomatal patterning resulting from signals moving from mature to developing leaves, we constructed a dual-chamber growth system in which rosette and cauline leaves of Arabidopsis thaliana were subjected to differing p[CO2]. Young rosette tissue was found to adjust stomatal index (SI, the proportion of stomata to total cell number) in response to both the current environment and the environment experienced by mature rosette tissue, whereas cauline leaves appear to be insensitive to p[CO2] treatment. It is likely that cauline leaves and cotyledons deploy mechanisms for controlling stomatal development that are related to, but distinct from, that operating in rosette leaves. The effect of p[CO2] on stomatal development reappears in cotyledons of the next generation, however this effect does not occur in pre-germination stomatal lineage cells but in only after germination. Moreover, these data suggest that p[CO2] affects regulation of stomatal development specifically through the development of satellite stomata and not the core pathway. To our knowledge, this is the first report identifying developmental steps responsible for altered stomatal patterning to p[CO2].

Miranda Haus is a post-doc in the lab of Brad Day.