Potassium deficiency induces the biosynthesis of oxylipins and glucosinolates in Arabidopsis thaliana.

BACKGROUND

Mineral fertilization and pest control are essential and costly requirements for modern crop production. The two measures go hand in hand because plant mineral status affects plant susceptibility to pests and vice versa. Nutrient deficiency triggers specific responses in plants that optimize nutrient acquisition and reprogram metabolism. K-deficient plants illustrate these strategies by inducing high-affinity K-uptake and adjusting primary metabolism. Whether and how K deficient plants also alter their secondary metabolism for nutrient management and defense is not known.

RESULTS

Here we show that K-deficient plants contain higher levels of the phytohormone jasmonic acid (JA), hydroxy-12-oxo-octadecadienoic acids (HODs) and 12-oxo-phytodienoic acid (OPDA) than K-sufficient plants. Up-regulation of the 13-LOX pathway in response to low K was evident in increased transcript levels of several biosynthetic enzymes. Indole and aliphatic glucosinolates accumulated in response to K-deficiency in a manner that was respectively dependent or independent on signaling through Coronatine-Insensitive 1 (COI1). Transcript and glucosinolate profiles of K-deficient plants resembled those of herbivore attacked plants.

CONCLUSIONS

Based on our results we propose that under K-deficiency plants produce oxylipins and glucosinolates to enhance their defense potential against herbivorous insects and create reversible storage for excess S and N.