New perspectives into jasmonate roles in maize

Abstract

It is well-known from the model dicotyledonous plants, Arabidopsis and tomato, that jasmonates (JAs) act as defense hormones in planta due to their potent ability to mediate defensive responses against insect/pathogen attacks or harsh environmental conditions. JA is also required for various developmental processes such as male fertility, seed maturation, root extension, and leaf senescence. In our recently published Plant Cell paper, the multiple roles of JA in the monocotyledonous agro-economically important model plant, maize, were investigated by comprehensive analysis of JA-deficient double mutant disrupted in the two oxophytodienoate reductase genes, OPR7 and OPR8. These two genes are the closest orthologs of the Arabidopsis JA-producing OPR3 and are the only maize OPRs required for JA biosynthesis. With this mutant, we previously showed that JA is essential for both male and female reproductive development, and required for the regulation of brace root pigmentation, leaf senescence, and defense against oomycete Pythium aristosporum, and beet armyworm (Spodoptera exigua). In this addendum, we expanded the investigation into the function of JA in elongation of sheaths, leaves, and roots, and its involvement in photomorphogenesis of seedlings.

Keywords:

• maize
• jasmonate biosynthesis
• tasselseeds
• Pythium

Disclosure of Potential Conflicts of Interest

No potential conflicts of interest were disclosed.

Acknowledgments

We wish to express our appreciation to Dr. Scott Finlayson for his help with these experiments.

Funding

This work was supported by National Science Foundation grant IOS-0925561 to M.K.