Loss of flower bud vigour in the Mediterranean shrub, Cistus albidus L. at advanced developmental stages

Abstract

To better understand aging in perennials, age-related changes in the physiology of leaves and flower buds of the Mediterranean shrub, Cistus albidus L. were evaluated. Two groups of different ages (5 and 10 years old), both at advanced developmental stages but of similar size, were compared. Total plant biomass, biomass produced per apical meristem and levels of cytokinins, abscisic acid and jasmonic acid in leaves and flower buds, as well as flower production, were measured. No differences in plant size, vegetative growth rates and levels of phytohormones in leaves were observed between 5- and 10-year-old plants. However, they showed significant differences in flower bud development; the older plants having reduced vigour, with 29.6% of flowers reaching anthesis compared to 52.5% in the younger plants. Furthermore, endogenous concentrations of zeatin and abscisic acid in flower buds at stage I (start of flower organ formation) were 61% and 41%, respectively, smaller in 10- than in 5-year-old plants. At stage II (with all flower organs formed), zeatin and abscisic acid concentrations decreased by ca. 90% and 80%, respectively, but differences between age groups were still evident (60% and 29% for zeatin and abscisic acid, respectively). Jasmonic acid levels in flower buds decreased by 80% from stage I to II, but did not differ between age groups. Despite reductions in flower bud vigour, total number of flowers per individual was not significantly different between age groups, so that an age-related loss in reproductive vigour at the organ level did not lead to a decrease in flower production at the whole plant level.

Genus Cistus: a model for exploring labdane-type diterpenes' biosynthesis and a natural source of high value products with biological, aromatic, and pharmacological properties

“…The main vitamin E compound in C. albidus seeds was α-tocopherol, whose content was higher in mature plants than the younger ones (Müller et al, 2014). Similarly, seeds of mature plants had higher concentrations of both salicylic acid and jasmonic acid, which was not the case in flowers and leaves, where no concentration differences were observed between the age groups (Oñate and Munné-Bosch, 2010). The adaptability of the species to drought involved an increase in abscisic (ABA) and ascorbic acid (AA) levels, as well as leaf H 2 O 2 concentrations, localized mainly in mesophyll cell walls, xylem vessels, and differentiating sclerenchyma cells (Jubany-Marí et al, 2009).…”

“…The production of phytohormones and vitamins were studied in C. albidus seeds (Müller et al, 2014), leaves, and flowers (Oñate and Munné-Bosch, 2010), in relation to plant maturity. The main vitamin E compound in C. albidus seeds was α-tocopherol, whose content was higher in mature plants than the younger ones (Müller et al, 2014).…”

Environmental predictors of shrubby cinquefoil (Dasiphora fruticosa) habitat and quality as host for Maine’s endangered Clayton’s copper butterfly (Lycaena dorcas claytoni)

“…Juvenile shrubs typically do not flower or produce seeds (Bond 2000), and bloom vigor may decrease in older shrubs (Oñate and Munné-Bosch 2010), potentially limiting resources for nectaring butterflies. Dasiphora fruticosa regenerates clonally as well as through recruitment of seedlings (Elkington and Woodell 1963;Lent and Reier 1999).…”

“…As perennials age, resource allocation shifts from growth and leaf expansion to reproduction (Bond 2000). Plant age may affect bloom production and vigor (Oñate and Munné-Bosch 2010) and nectar quality and availability (Búrquez and Corbet 1998). Age-dependent nectar quality and quantity potentially can affect butterfly population persistence particularly for those reliant on few or isolated host plant species.…”

Age and sex-related changes in cytokinins, auxins and abscisic acid in a centenarian relict herbaceous perennial

“…Similarly, it is still not clear that the reproductive capacity of plants decreases with age. While some studies have shown that the reproductive potential of perennial plants decreases with age (Herrera and Jovani 2010), others indicate that flower production increases with leaf area and specific climatic conditions, irrespective of plant age (Ehlers and Olesen 2004;Oñate and Munné-Bosch 2010).…”