Avoidance or tolerance: late frost resilience mechanisms in grapevine

Abstract

Climate change has compressed grapevine phenology, advancing budbreak without a corresponding reduction in the probability or timing of late frosts. Consequently, late frost risk has increased in Trentino and is projected to rise across many European viticultural regions. This research aims to identify resilience mechanisms to mitigate such damage.

Sixteen interspecific hybrids (Vitis vinifera × Vitis spp.) and a V. vinifera Nosiola clone were analyzed over two seasons. We monitored: (i) phenology at budbreak, (ii) survival rates in controlled frost simulations, and (iii) the accumulation of primary metabolites and polyphenols. Additionally, a comparative RNA-Seq experiment and parallel metabolomic analysis were conducted on tolerant versus sensitive genotypes.

Two distinct strategies emerged: frost avoidance and frost survival. Avoidance genotypes reach sensitive phenological stages only after higher thermal accumulation, exhibiting plasticity and varying degrees of budbreak synchrony. Tolerance genotypes withstand freezing temperatures through specific anatomical traits, metabolic profiles, and transcriptomic regulation. These results were interpreted in the context of the genotypes’ pedigree.

The existence of these distinct mechanisms underscores the necessity of an integrated study approach. While budbreak dynamics are key targets for breeding programs, tolerance mechanisms can be exploited through agronomic innovations, such as UV-C radiation treatments.