Family Business: Multiple Members of Major Phytohormone Classes Orchestrate Plant Stress Responses

Abstract

Low-molecular-weight compounds such as jasmonic, abscisic and salicylic acids are commonly thought to be regulators of plant stress responses. However, it is becoming clear that these molecules, often referred to as phytohormones, are only a part of bigger groups of compounds with biological activity. We propose that the concept of "hormone families" may help to better understand plant physiological responses by taking into account not only the alleged main regulators, but also their precursors, conjugates and catabolites. Novel approaches to profile potentially active compounds in plants are discussed.

Induced resistance in maize is based on organ‐specific defence responses

“…Plant hormones and numerous other compounds with biological activity are of utmost importance for the control of targeted reactions of plants during stress situations (Erb and Glauser, ). The pattern of hormonal adaptations during leaf and root infections of maize with C. graminicola is in accordance with the transcriptome data: infected roots reacted faster than leaves and exhibited significant changes in SA, JA and ABA levels compared to control plants.…”

Expression of a bacterial feedback‐insensitive 3‐deoxy‐d‐arabino‐heptulosonate 7‐phosphate synthase of the shikimate pathway in Arabidopsis elucidates potential metabolic bottlenecks between primary and secondary metabolism

“…Salicylate can be synthesized from chorismate, cinnamate or benzoate (Chen et al. , 2009) and its conjugates include several glucosylated forms, such as salicyloyl glucose ester and salicyloyl glucoside (Erb & Glauser, 2010). Altered production of Phe‐derived secondary metabolites has also been observed previously on expression of a bacterial bifunctional PheA gene (Tzin et al.…”

Induced Immunity Against Belowground Insect Herbivores- Activation of Defenses in the Absence of a Jasmonate Burst

“…Furthermore, the capacity of roots to synthesize specific signals following herbivory may be different from the leaves: The JA precursor linolenic acid, for example, is much less abundant in the roots than in the leaves. Instead, roots contain higher concentrations of linoleic acid (Li et al 2003), the precursor of dihydro-JA, one of many other jasmonates with biological activity (Blechert et al 1995;Erb and Glauser 2010). It is tempting to speculate that other jasmonates than JA-Ile may be important for defense signaling in the roots.…”