Abstract Detail

Ecophysiology

Huber, John A. [1], Stewart, J. Ryan [1].

Exploring the possibility of photosynthetic plasticity in Agave sensu lato.

Several succulent species exhibit the capability to shift from CAM to C₃ photosynthesis under changing environmental conditions. Such plasticity could enable plants native to harsh desert environments, such as agaves, to take advantage of seasonally abundant yet ephemeral water sources for growth and development. While this capacity was observed in Agave deserti, it has not been observed in any other species within Agave sensu lato. Furthermore, Agave utahensis showed no capacity for facultative CAM expression in a preliminary study. In order to determine the prevalence of CAM plasticity in species within Agave sensu lato, this study subjected seedlings and mature plants from multiple species within the clade to soil moisture levels ranging from dry to saturated conditions. These experiments found that young tissues primarily use the C₃ photosynthetic pathway, and transition to CAM as development progresses. It was also found that species within Agave sensu lato responded differently to moisture treatments, with some species exhibiting flexibility in CAM expression and others remaining obligate in the expression of CAM. The ability to shift from the relatively costly CAM pathway to C₃ photosynthesis may account for reports of high production rates in some Agave species, despite the perceived restrictions to growth rates imposed by their high water-use efficiency.

1 - Brigham Young University, Department of Plant and Wildlife Sciences, 4105 Life Sciences Building, Provo, UT, 84602, USA

Keywords:
Agave
Succulent
Photosynthesis
Water stress.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PEP009
Abstract ID:1083
Candidate for Awards:Physiological Section Best poster presentation,Physiological Section Physiological Section Li-COR Prize