Project description:In the family Fagaceae, fertilization is delayed by several weeks to more than one year after pollination, leading to one- or two-year fruiting species depending on whether fruiting occurs in the same or the next year of flowering. Although delayed fertilization was recorded over a century ago, underlying mechanisms remain to be explored. To uncover the key genes associated with delayed fertilization, we obtain and analyze the comparative molecular phenology data over two years in one-year (Quercus glauca) and two-year fruiting species (Lithocarpus edulis).
Project description:In the family Fagaceae, fertilization is delayed by several weeks to more than one year after pollination, leading to one- or two-year fruiting species depending on whether fruiting occurs in the same or the next year of flowering. Although delayed fertilization was recorded over a century ago, underlying mechanisms remain to be explored. To uncover the key genes associated with delayed fertilization, we obtain and analyze the comparative molecular phenology data over two years in one-year (Quercus glauca) and two-year fruiting species (Lithocarpus edulis).
Project description:Priming of plant defenses provides increased plant protection against herbivores and reduces the allocation costs of defense. Defense priming in woody plants remains obscure, in particular due to plant development traits such as the endogenous rhythmic growth displayed by oaks (Quercus robur). By using bioassays with oak microcuttings, and by combining transcriptomic and metabolomic analyses, we investigated how leaf herbivory by Lymantria dispar and root inoculation with the ectomycorrhizal fungus Piloderma croceum prime oak defenses. We further investigated how defense priming is modulated by rhythmic growth of the oaks. A first herbivory challenge in oak leaves primed newly grown leaves for an enhanced induction of jamonic acid (JA)-related direct defenses, or enhanced emission of volatiles, depending on the specific growth stage at which the plants where challenged. Root inoculation with Piloderma abolished the enhanced induction of JA-related defenses and volatile emission. Our results indicate that a first herbivore attack primes direct and indirect defenses of newly formed oak leaves, and that the specific display of defense priming is modulated by rhythmic growth. Our results further show that the priming memory in oaks can be transmitted to the next growth cycle even to the leaves of the new shoot unit.