Trichomes related to an unusual method of water retention and protection of the stem apex in an arid zone perennial species

Reproductive stem apex of Lychnophora diamantinana (photo credit: Lusa et al.).
Reproductive stem apex of Lychnophora diamantinana (photo credit: Lusa et al.).

The adaptation strategies of plants to harsh environments are among the most interesting subjects in plant biology. Several studies have investigated the role played by trichomes in protecting plant organs in these conditions. In a new study published in AoB PLANTS, Lusa et al. report an unusual way of protecting the stem apex of Lychnophora diamantinana. This species is endemic to the Brazilian campos rupestres (rocky fields), a region characterised by intense solar radiation and water deficits. The authors found that the terminal cell of its non-glandular trichomes undergoes partial degradation of the cell wall, producing a highly hydrated, hyaline material that protects the stem apex against desiccation. The secretion of glandular trichomes may also repel herbivore and pathogen attack.