Histology of resin vesicles and oleoresin terpene composition of conifer seeds

Abstract

The seed coats of several conifers contain terpene-filled resin vesicles, which may be involved in the protection of the dormant embryo and the seed storage tissue against herbivores or pathogens. We analyzed the terpenoid composition of seeds from four Abies species (Abies amabilis Douglas ex J. Forbes, Abies balsamea (L.) Mill., Abies grandis (Douglas ex D. Don) Lindl., and Abies lasiocarpa (Hook.) Nutt.), two Thuja species (Thuja plicata Donn ex D. Don and Thuja occidentalis L.), and three Tsuga species (Tsuga canadensis (L.) Carrière, Tsuga mertensiana (Bong.) Carrière, and Tsuga heterophylla (Raf.) Sarg.) and examined histological features of resin vesicles in seeds from one species from each genus. Resin vesicle morphology was generally similar among the species analyzed. The composition of the seed terpenes varied largely between species. The described seed terpene profiles of the nine species will serve as a foundation for future studies into the function of seed terpenes and resin vesicles in the seed coat.

Resin vesicles in conifer seeds: morphology and allelopathic effects

“…The variation within a species across its geographic range was not examined. This work complements the histological examination of these resin vesicle-containing conifer seeds recently described (Kshatriya et al 2018). The percentage of seed dry weight composed of resin vesicle constituents we measured (7-D r a f t 21%) was consistent with those found for these species by other methods (Kshatriya et al 2018), and with the 20% reported in the European silver fir (Abies alba Mill.)…”

“…Smirnoff 1972;Zavarin et al 1977). Kshatriya et al (2018) have recently identified and quantified the monoterpenes and diterpenoids found in these and the other resin vesicle-containing conifer seeds studied here. Additional studies are needed to establish whether these ketones confer this difference in inhibitory potency, and to quantify the inhibitory potency of each resin vesicle constituent.…”

“…Interestingly, when quantifying the composition of individual resin vesicles on seeds from the same and different cones, Čermák (1987) also found significant differences in the composition of the resin depending upon the location of the resin vesicle around the seed, and that these differences were consistent between seeds. Recently, a more comprehensive survey of the terpenoid contents of conifer resin vesicles was published (Kshatriya et al 2018). That study quantified the monoterpenoids and diterpenoids in the same species of conifers as were used in the present study.…”

Diterpene Resin Acids and Olefins in Calabrian Pine (Pinus nigra subsp. laricio (Poiret) Maire) Oleoresin: GC-MS Profiling of Major Diterpenoids in Different Plant Organs, Molecular Identification and Expression Analysis of Diterpene Synthase Genes

“…For instance, structurally related labdane-type diterpenoids, such as ferruginol and derivative compounds, act as defence metabolites in many Cupressaceae species [3,7,8]. On the other hand, diterpene resin acids (DRAs), together with mono-and sesqui-terpenes, are the main components of the oleoresin defence system in the Pinaceae species (e.g., conifers), and have been shown to provide an effective barrier against stem-boring weevils and associated pathogenic fungi [9][10][11][12].…”

Seed predation and dispersal by small mammals in a landscape of fear: effects of personality, predation risk and land‐use change

“…One seed species, white pine Pinus strobus , represented a highly preferred seed for Peromyscus maniculatus and the other, balsam fir Abies balsamea , represented a seed of low preference (Abbott 1962, Duchesne et al 2000, Boone and Mortelliti 2019) (Supporting information). With a relatively low handling time, white pine delivers approximately 0.102 kcal/seed, while balsam fir has only 0.046 kcal/seed (Boone and Mortelliti 2019) and unpalatable secondary compounds (resins and terpenes) (Lobo and Millar 2011, Kshatriya et al 2018). White pine is slightly larger than balsam fir, by approximately 0.01 g (Boone and Mortelliti 2019) (Supporting information).…”