Cold acclimation and deacclimation in wild blueberry: Direct and indirect influence of environmental factors and non-structural carbohydrates

Abstract Through the annual cycle of plant growth and dormancy, winter season leads to profound metabolic changes allowing plants undergo cold acclimation. In boreal environments, conditions are changing rapidly likely cause damage commercial wild lowbush blueberry. this study, we addressed level frost hardiness determined role environmental factors nonstructural carbohydrates (NSCs) on hardiness. From autumn spring, stem sections Vaccinium angustifolium myrtilloides were harvested each month in a blueberry field assess relative electrolyte leakage calculate temperature at which 50% cells lysed [LT50 ( °C)], used as index. Stems also collected soluble starch. Correlations, principal component analysis (PCA) structural equation modeling (SEM) determine how NSCs directly or indirectly influence Frost reached its lowest December January with LT50 dropping below -60 °C. Seasonality hardening was closely linked photoperiod temperature, generating clock-wise hysteretic loops that divide into acclimation, from September January, deacclimation, end May. Environmental such more important determining during either direct indirect effect through an starch degradation, increasing carbohydrate content. During carbohydrates, especially raffinose, further induced stronger regulation Direct biological raffinose defined deacclimation. However, negative concentration could increase vulnerability warming events.