Centre for Plant Success Webinar Series: Christopher Blackman and Kate Johnson

Christopher Blackman

Plant drought experiments: why, what, when, where and how?

Drought is a major environmental stress that negatively impacts plant growth and productivity in natural and agricultural systems. Given drought is increasing in intensity with human-induced global heating, there is an urgent need to better understand how plants respond to water-deficit and identify the traits and mechanisms associated with drought adaptation and survival in drought prone environments.

One way to address this need is to run a drought experiment. But How? In this talk, I describe some of the different field-based and experimental approaches researchers (myself included) use to study plant adaptation and plant responses to drought. These include examining trait variation along environmental gradients of moisture availability, long-term field monitoring, reciprocal transplant experiments and field trials, rain-exclusion, and glasshouse experiments. I highlight some of the benefits and challenges of these different approaches and emphasise the need to understand plant physiological processes when running drought related phenotype selection and genetic studies.

Kate Johnson

A trade-off between growth rate and xylem cavitation resistance in Callitris rhomboidea

The ideal plant water transport system is one that both is efficient, and resistant to drought-induced damage (xylem cavitation), however, species rarely possess both. This may be explained by trade-offs between traits, yet thus far, no proposed trade-off has offered a universal explanation for the lack of both highly drought-resistant and highly efficient water transport systems. In our recent paper, we found evidence for a new trade-off, between growth rate and resistance to xylem cavitation, in the canopies of a drought-resistant tree species (Callitris rhomboidea), presenting an alternative the ‘safety vs. efficiency’ hypothesis. I will discuss what we found, what it means and some possible mechanistic explanations for the trade-off. Understanding whether this trade-off exists within and between species will help us to uncover what drives and limits plant drought resistance more broadly.

This event is open to Centre Members only. If you are a Centre Member who would like to attend, please contact admin@plantsuccess.org for the Zoom invitation.