Leaf epicuticular wax content changes under different rainfall regimes, and its removal affects the leaf chlorophyll content and gas exchanges of Aspidosperma pyrifolium in a seasonally dry tropical forest

• DOI: 10.1016/j.sajb.2017.03.033
• Publication Date: 2017-06-21T13:20:02Z
• Authors: C.D. Medeiros; H.M. Falcão; J. Almeida-Cortez; D.Y.A.C. Santos; A.F.M. Oliveira; M.G. Santos
• Keywords: Epicuticular wax; Stomatal Conductance; Cuticle (hair)

Leaf epicuticular waxes are the interface between leaves and atmosphere, acting in reduction of water loss. Therefore, we believe this part cuticle influences species ecophysiological responses under different rainfall conditions. In study, investigated how leaf wax (EW) Aspidosperma pyrifolium contributes to desiccation reduction, its impacts on gas exchanges. We selected a site preserved tropical seasonally dry forest, analysed both intact (control) that had EW removed mechanically (without - WW). All measurements were made May, for two consecutive years, with low (2013) high (2014) precipitation. The results show strongly maintenance photosynthetic rates leaves, which able keep their stomata open longer periods, use efficiency. WW treatment always presented lower A, gs WUE rates, even wet year, however, most physiological losses observed year. plants degraded chlorophyll invested phenols as strategy prevent photo damage caused by stomatal conductance reduction. Chemically, major constituents A. triterpene alcohols. Despite higher content chemical composition was not associated protection against loss, since triterpenoids suggest defence mechanism herbivory. concluded that: (i) is important exchanges metabolism pyrifolium, (ii) effects removal more intense years.