Induction of adaxial stomata in Vitis

 Photo credit: PNAS

Epidermal leaf peels show Vitis leaves are hypostomatal, having no stomata on the adaxial side (A), but gall formation generates stomata in increasing density at closer proximity to the gall (out of picture Lower Right; B). Abaxial tissue without or adjacent to galls have similar stomata patterning (Table 1).

Leaf-galling Phylloxera on grapes reprograms host metabolism and morphology

by Nabity P. D., Haus M. J., Berenbaum M. R., DeLucia E. H. (2013)

in PNAS – vol. 110 no. 41, 16663–16668

Epidermal leaf peels show Vitis leaves are hypostomatal, having no stomata on the adaxial side (A) – http://www.pnas.org/content/110/41/16663/F1.medium.gif

Significance

Some herbivorous insects induce galls, abnormal structures, in their host plants, benefiting the gall-forming parasite by providing nutritive tissue. The gall-forming insect Phylloxera induces stomata, openings through which plants regulate water and CO₂, on the upper surface of grape leaves where they typically do not occur. Carbon uptake and transpiration by induced stomata facilitate nutrient acquisition by gall tissue and phylloxera. Moreover, gall formation reprograms the host-leaf transcriptome to increase transcripts associated with sucrose mobilization and glycolysis and decrease defense-related transcripts. Thus, stomata induction by phylloxera reconfigures leaves to increase carbon gain, to partially offset negative impacts of gall formation.