Current projects
Effects of whole ecosystem warming on cold hardiness and dormancy of woody perennials
At SPRUCE, located at the Marcell Experimental Forest, we are investigating how warming treatments affect the cold hardiness and dormancy of the woody perennials from a boreal forest. The experiment is located at the southern range of the boreal forest, and therefore any warming moves these plants away from current distribution. One of the most influencing factors limiting plant distribution is low temperature. Understanding how different plant species adapt to low temperatures and avoid damage is a challenge because it involves both dormancy and cold hardiness, and doing research outside during the winter! Perennial plants become dormant as a mechanism to survive low temperatures that could otherwise kill vegetative and reproductive tissues. Once dormancy in buds is established, plants must also become cold hardy to survive such temperatures. While cold hardiness maximum appears to be a species (and genotype/cultivar) characteristic (e.g., USDA Cold Hardiness Zone), getting to that maximum requires exposure to low, non-killing temperatures. Therefore, understanding the responses of trees and shrubs growing in an artificial, active heating system will give us the opportunity to find some responses in their adaptation mechanisms and how they will behave in warmer winters in the future.
Chilling effects on grapevine cold hardiness and dormancy are separate but intertwined
Plants overcome dormancy through prolonged exposure to low temperatures, conceptualized as “chill units”. The specific quantity of chill units that buds require to break dormancy is referred to as the “chill requirement” and is thought to be cultivar specific. However, the process by which buds monitor and accumulate chill units to break dormancy is unknown, which has impeded development of chill models that are effective for distinct growing regions. We are applying a novel dormancy assessment concept, known as deacclimation potential (Ψdeacc), that is based on deacclimation kinetics to assess low temperature contribution to chill and to identify opportunities to improve chill models or develop a new chill model.
Optimizing tissue culture protocols for Forsythia
Forsythias (Forsythia spp.) are woody perennial bushes that produce abundant floral buds that can be easily characterized for their dormancy status and cold hardiness. Similar to the way Arabidopsis has served as a model plant for genetic studies, we look to utilize forsythia to serve this role to study characteristics that are only present in woody perennials (while avoiding some difficulties presented by poplar). Tissue culture is a necessary step for transformation protocols, and is a popular method used to propagate identical copies of plants that are disease free for horticultural production. Tissue culture protocols are common and easier for herbaceous plants, but optimization of this technique is needed for this woody ornamental species, and a requirement for future genetic studies. We will formulate media recipes that target multiple plant anatomical components of forsythia, a popular shrub, to optimize micropropagation protocol. Following the development of an in-vitro system for forsythia, initiation of genetic transformation can begin.
Recent publications
Kovaleski AP. Woody species do not differ in dormancy progression: differences in time to budbreak due to forcing and cold hardiness. Proc. Natl. Acad. Sci. USA 119, e2112250119 (2022).
North M, Workmaster BA, Atucha A. Effects of chill unit accumulation and temperature on woody plant deacclimation kinetics. Physiologia Plantarum 174, e13717 (2022).
Kovaleski AP, Grossman JJ. Standardization of electrolyte leakage data and a novel liquid nitrogen control improve measurements of cold hardiness in woody tissue. Plant Methods 17, 53 (2021).
North M, Workmaster BA, Atucha A. Cold hardiness of cold climate interspecific hybrid grapevines grown in a cold climate region. Am. J. Enol. Vitic. 72, 318-327 (2021).
We strive to publish in open access journals such that it is accessible by everyone, but sometimes this can be cost prohibitive. If you need access to anything we have published, please don’t hesitate to send us an email.