Plant communication mediated by volatile organic compounds (VOCs)

Vocabulary flashcards covering key terms, VOCs, enzymes, and concepts from the notes on plant communication via volatile organic compounds.

VOC (volatile organic compound)

A volatile chemical emitted by plants to warn or communicate; can be a single molecule or a blend; facilitates within‑plant signaling and plant‑to‑plant communication, and can also attract natural enemies or pollinators.

GLV (green leaf volatile)

A major group of VOCs derived from C18 fatty acids (lipids) via the lipoxygenase (LOX) pathway; includes C6 aldehydes, alcohols, and esters released when plants are damaged.

MeJA (methyl jasmonate)

A volatile oxylipin derived from jasmonic acid; acts as an interplant signal that can induce defense gene expression and production of defensive proteins such as proteinase inhibitors.

JA (jasmonic acid)

A plant hormone in the oxylipin pathway that coordinates defense responses; part of the signaling cascade triggered by VOCs and wounding.

MeSA (methyl salicylate)

A mobile volatile signal that can induce systemic acquired resistance (SAR) in both emitter and receiver plants.

Ethylene

A gaseous plant hormone that modulates defense responses, can amplify VOC emissions and defense gene expression, and interacts with other signaling pathways (e.g., JA, GLVs).

cis-Jasmone

A jasmonate-related metabolite with a distinct mode of action from JA; induces defense responses, secondary metabolite synthesis, and can attract natural enemies; reduces pest infestation.

DMNT (dimethyl nonatriene)

A homoterpene GLV (one of the wound-induced volatiles) released upon herbivory that helps modulate defense gene expression (e.g., LOX, FPS, PR genes).

TMTT (trimethyltridecaatriene)

A homoterpene GLV produced in response to herbivory; part of the VOC blend that signals defenses and can affect gene expression.

(E)-β-ocimene

A monoterpene emitted by damaged plants; part of VOC blends that can modulate defense signaling and gene expression in receiver plants.

(Z)-3-hexenal

A C6 GLV aldehyde produced during wounding; a component of wound-induced blends influencing defense responses and secondary metabolism.

(E)-2-hexenal

A GLV aldehyde involved in wound-induced signaling and defense gene regulation within VOC blends.

(Z)-3-hexen-1-ol

A GLV alcohol produced after damage; can lead to emission of (Z)-3-hexenyl acetate and MeSA and induce defense-related genes (e.g., LOX, PAL).

(Z)-3-hexen-1-yl acetate

An ester GLV produced from (Z)-3-hexen-1-ol; contributes to the wound VOC blend and signaling for defense responses.

(E)-β-farnesene

A sesquiterpene VOC often emitted after damage; part of defense signaling blends and can affect insect behavior and plant defenses.

LOX (lipoxygenase)

A key enzyme in the oxylipin pathway that generates GLVs and contributes to jasmonate biosynthesis; central to VOC production after damage.

PAL (phenylalanine ammonia-lyase)

A key enzyme in the phenylpropanoid pathway; its activity is associated with defense metabolite production and is upregulated by VOC signaling.

DXS (1-deoxy-D-xylulose 5-phosphate synthase)

An enzyme in the MEP pathway for isoprenoid/terpenoid biosynthesis; provides precursors for terpenoid VOCs in defense signaling.

CPPase (chrysanthemyl diphosphate synthase)

An enzyme involved in pyrethrin biosynthesis (in Chrysanthemum cinerariaefolium); required for the production of insecticidal pyrethrins.

AOS (allene oxide synthase)

An enzyme in the oxylipin pathway that leads to jasmonate and related signals; important for JA/MeJA production in VOC-mediated signaling.

Plant-Plant communication

Communication between plants via VOCs emitted by damaged plants that primes or activates defenses in nearby undamaged plants; influenced by blend composition and concentration, distance, and environmental conditions.

Within-Plant communication

Signaling within the same plant, often via nonvolatile signals, that coordinates defense responses (e.g., increased pyrethrin biosynthesis in distant leaves after wounding).

Priming (VOC-induced priming)

A phenomenon where prior exposure to VOC signals prepares receiver plants to respond more vigorously to future attacks, sometimes without obvious metabolite or gene expression changes.

Eavesdropping (interspecific VOC signaling)

Plants can respond to VOCs emitted by other species, enabling cross-species defense signaling and potentially driving coevolution between plants and herbivores.

Pyrethrin biosynthesis (in Chrysanthemum cinerariaefolium)

Synthesis of pyrethrins, insecticidal metabolites; wound-induced VOC blends (five components) can upregulate pyrethrin production; requires all components and proper concentrations for effect.

Sagebrush MeJA signaling

Methyl jasmonate emitted by sagebrush (Artemisia tridentata) was an early example showing interplant signaling that increases defense (e.g., proteinase inhibitors) in intact plants.