Tagged: seedling



Drying out defenses: drought reduces tree defense system

Drought stress is becoming increasingly common with climate change, with negative impacts on tree growth and survival. The mechanisms of drought mortality in trees are often attributed to carbon starvation or hydraulic failure, however disease and herbivory could also cause mortality under drought. For this to happen, tree defense systems against pathogens and herbivores would have to be weakened under drought – but are they? Recently, in Tree Physiology, Sarah MacAllister and colleagues look at metabolic changes in Scots pine leaves during drought stress to determine whether plant defenses are weakened. They use an untargeted metabolomics approach – essentially measuring...

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A conceptual diagram of the processes studied

Integration between developmental pathways during reserve mobilization in palm seeds

Palm seeds are interesting models for studying seed reserve mobilization at the tissue level due to the abundance and complexity of reserves stored in their living endosperm cells and the development of a highly specialized haustorium. Dias et al. studied structural and physiological aspects of the initial phases of reserve mobilization in seeds of a neotropical palm, Butia capitata, and sought to characterize the interactions between the different developmental pathways of the haustorium and endosperm. The authors performed morphological and histochemical evaluations of the haustorium, the endosperm adjacent to the embryo, and the peripheral endosperm of dry, imbibed, dormant seeds...

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Seeds and seedlings of A. aculeata, indicating (on the left) the development phases of the saxophone stem

Saxophone stem ontogenesis and functions in Acrocomia aculeata

The underground system known as the saxophone stem produced by seedlings of certain palm species exhibits unique growth patterns and distinctive morphologies. Nascimento e Souza et al. performed morpho-anatomical evaluations of seedlings during the development of the saxophone stem in Acrocomia aculeata, a neotropical oleaginous palm. They found the development of the saxophone stem is distinct from other underground systems previously described, and involves three processes: growth and curvature of the cotyledonary petiole, expansion and curvature of the hypocotyl, and expansion of the plumule internodes. The saxophone stem structure represents an important adaptation to dry environments by promoting the burial...

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