Advances for plant functional ecology: the importance of the phyllosphere and the concept of holobiont

Plant functional ecology is based on the use of functional traits as descriptors of organisms' responses to variations in conditions and resources. Traditionally, plants have been the most studied group, which has allowed great advances in this topic. However, the functional approach has neglected the fact that organisms such as fungi, bacteria and lichens occurring on leaves directly affect the performance of macro-organisms. In this sense, the concept of holobiont - the integrated phenotype of the plant traits, and their endo- and epiphytic organisms, is fundamental to understanding the ability of macro-organisms to cope with environmental filters. Integrating the plant response traits phyllosphere traits will improve one of the loose foundations of functional ecology due to the merge of functional ecology, plant physiology and microbiology.