RT Journal Article SR Electronic T1 The Lanata trichome mutation increases stomatal conductance and reduces leaf temperature in tomato JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.02.11.943761 DO 10.1101/2020.02.11.943761 A1 Karla Gasparini A1 Ana Carolina R. Souto A1 Mateus F. da Silva A1 Lucas C. Costa A1 Cássia Regina Fernandes Figueiredo A1 Samuel C. V. Martins A1 Lázaro E. P. Peres A1 Agustin Zsögön YR 2020 UL http://biorxiv.org/content/early/2020/02/12/2020.02.11.943761.abstract AB Background and aims Trichomes are epidermal structures with an enormous variety of ecological functions and economic applications. Glandular trichomes produce a rich repertoire of secondary metabolites, whereas non-glandular trichomes create a physical barrier against biotic and abiotic stressors. Intense research is underway to understand trichome development and function and enable breeding of more resilient crops. However, little is known on how enhanced trichome density would impinge on leaf photosynthesis, gas exchange and energy balance.Methods Previous work has compared multiple species differing in trichome density, instead here we analyzed monogenic trichome mutants in a single tomato genetic background (cv. Micro-Tom). We determined growth parameters, leaf spectral properties, gas exchange and leaf temperature in the hairs absent (h), Lanata (Ln) and Woolly (Wo) trichome mutants.Key results Shoot dry mass, leaf area, leaf spectral properties and cuticular conductance were not affected by the mutations. However, the Ln mutant showed increased carbon assimilation (A) possibly associated with higher stomatal conductance (gs), since there were no differences in stomatal density or stomatal index between genotypes. Leaf temperature was furthermore reduced in Ln in the early hours of the afternoon.Conclusions We show that a single monogenic mutation can increase glandular trichome density, a desirable trait for crop breeding, whilst concomitantly improving leaf gas exchange and reducing leaf temperature.HIGHLIGHT A monogenic mutation in tomato increases trichome density and optimizes gas exchange and leaf temperature