To grow or to defend? - Deciphering defense-growth strategies in Scots pine and Norway spruce under local light conditions in Sweden.

Lignification indicates a pause in plant growth.

Generally, shade (low R:FR ratio) causes a decrease in lignin synthesis, which makes the plant more susceptible to diseases.

Instead, recently we detected enhanced lignin synthesis in Scots pine and Norway spruce in response to shade along with expression of higher number of defense-related genes in northern populations of both conifers as compared to those in the southern ones.

Considering that northern conifer populations are exposed to extended shade during their growth season, it is reasonable to wonder the effect of higher lignification on growth-defense trade-offs in the northern populations Our project aims to unravel the lignin pathway in conifers under shade by characterizing the metabolites involved, which remains unexplored in conifers.

We will decipher if the enhanced lignin synthesis coupled with the expression of defense-related genes is able to confer higher degree of disease resilience in the northern pine and spruce populations as compared to the southern ones when exposed to shade. This project will combine multiple technologies such as spectroscopy, microscopy,transcriptomics and metabolomics.

Results will contribute to improve designing of breeding programs of both the economically important conifers for Scandinavian forestry – selection and assisted migration of better surviving and healthier trees with higher resilience.