Differential induction of trichomes by three herbivores of black mustard

Abstract

Specificity of plant induction responses may be important to the interactions between mustards and insect herbivores. This study compared the effects of the cabbage white butterfly, Pieris rapae (L.), cabbage looper, Trichoplusia ni (Hubner), and the mustard flea beetle, Phyllotreta cruciferae (Goeze) on induction of leaf trichome density, sinigrin concentration, and nitrogen concentration in black mustard, Brassica nigra (L.) Koch. Plants were damaged for 12 h at the four-leaf stage, with effort made to standardize the damage applied. Induction responses were measured on the fifth, seventh, ninth, and 11th leaves counted from the cotyledons. Seventh leaves of plants damaged by P. rapae had 76% more trichomes per unit area than controls, whereas equivalent leaves of plants damaged by the other two herbivores exhibited no response. Ninth leaves of plants damaged by T. ni had 113% more trichomes per unit area than controls, whereas equivalent leaves of plants damaged by the other two herbivores exhibited no response. Trichome densities of fifth and 11th leaves did not respond to treatments. Leaf sinigrin and nitrogen concentrations were not affected by the damage treatments. Differential plant trichome response to P. rapae and T. ni may have been due to differences in location of feeding during the damage treatment. Other cues, such as salivary components, may also have differed between the two herbivores. This study is one of the first to document differential effects of two herbivores from the same guild on induction of morphological resistance.

Induced Resistance in Mycorrhizal Tomato is correlated to Concentration of Jasmonic Acid

“…This observation is in accordance with the observation of Copetta et al and Kapoor et al, [12,27] . Trichomes are important structural barrier component of resistance and glandular trichomes are sites for accumulation of secondary metabolites [48] . Increase in foliar tissue density indicates induction of systemic resistance in mycorrhizal plants.…”

Jasmonic acid control of GLABRA3 links inducible defense and trichome patterning inArabidopsis

“…Wound-induced trichome formation has been reported in many plant species from diverse phylogenetic clades (Myers and Bazely, 1991;Agrawal, 1999;Traw and Dawson, 2002;Boughton et al, 2005;Holeski, 2007). It is known that the Myb-bHLH-WD40 complex is an evolutionarily conserved regulator of trichome development in Brassicaceae and Malvaceae, both of which belong to the Eurosid II clade of angiosperms (APG, 2003;Wang et al, 2004;Humphries et al, 2005;Gruber et al, 2006).…”

Root growth ofNicotiana attenuatais decreased immediately after simulated leaf herbivore attack

“…3,4,5 Acclimation occurs both on the biochemical and morphological level, e.g., by increasing defence compounds, 6 by synthesizing defence related proteins, by emitting volatiles to attract predators and parasites of herbivores 7 and by altering plant morphology via increased formation of trichomes, thorns or scleromorphy. 8,9 Many studies demonstrated resource based trade-offs between growth and defence on a large time scale (e.g. refs.…”