Jasmonoyl-l-Isoleucine Coordinates Metabolic Networks Required for Anthesis and Floral Attractant Emission in Wild Tobacco (Nicotiana attenuata)

摘要

Jasmonic acid and its derivatives (jasmonates []) play central roles in floral development and maturation. The binding of jasmonoyl-l-isoleucine () to the F-box of CORONATINE INSENSITIVE1 (COI1) is required for many -dependent physiological responses, but its role in anthesis and pollinator attraction traits remains largely unexplored. Here, we used the wild tobacco Nicotiana attenuata, which develops sympetalous flowers with complex pollination biology, to examine the coordinating function of homeostasis in the distinct metabolic processes that underlie flower maturation, opening, and advertisement to pollinators. From combined transcriptomic, targeted metabolic, and allometric analyses of transgenic N. attenuata plants for which signaling deficiencies were complemented with methyl jasmonate, , and its functional homolog, coronatine (), we demonstrate that (1) /-based signaling regulates corolla limb opening and a -negative feedback loop; (2) production of floral volatiles (night emissions of benzylacetone) and nectar requires / perception through COI1; and (3) limb expansion involves -induced changes in limb fresh mass and carbohydrate metabolism. These findings demonstrate a master regulatory function of the /COI1 duet for the main function of a sympetalous corolla, that of advertising for and rewarding pollinator services. Flower opening, by contrast, requires signaling-dependent changes in primary metabolism, which are not compromised in the COI1-silenced RNA interference line used in this study.