The plasma membrane ABC transporter Sl-ABCB5 mediates acylsugar secretion from tomato trichomes to confer insect resistance.
Lyu T, Han L, Jin J, Wang J, Zhou H
Summary
7.8/10Researchers identified a specific protein (Sl-ABCB5) that transports defensive chemicals in tomato plants' protective hairs, enabling them to resist insect pests. This discovery could enable breeding or engineering tomato varieties with enhanced natural pest resistance.
Key Findings
The ABC transporter Sl-ABCB5 mediates acylsugar secretion in tomato trichomes; CRISPR-Cas9 knockout mutants showed dramatically reduced acylsugar content and increased susceptibility to western flower thrips
In vitro transport assays using membrane vesicles and protoplasts confirmed Sl-ABCB5's ability to actively transport acylsugars across the plasma membrane
ABCB5 function is conserved across Solanaceae species (cultivated tomato, wild tomato, and black nightshade), indicating a general transport mechanism applicable to multiple crops
Original Abstract
Acylsugars are structurally diverse specialized metabolites secreted by glandular trichomes of Solanaceae plants and play a crucial role in defense against herbivores and pathogens. However, the mechanism of acylsugar secretion remains unclear. This study identifies and characterizes the plasma membrane ABC transporter Sl-ABCB5 as a key component in cultivated tomato (Solanum lycopersicum) trichome secretory cell acylsugar transport. Employing CRISPR-Cas9 generated Sl-ABCB5 knockout mutants, we observed a dramatic reduction in trichome acylsugar content, accompanied by increased susceptibility to western flower thrips (Frankliniella occidentalis). In vitro transport assays using both membrane vesicles and protoplasts confirmed the ability of Sl-ABCB5 to transport acylsugars. Furthermore, virus-induced gene silencing and CRISPR-mediated knockout of ABCB5 orthologs in wild tomato (S. pennellii) and black nightshade (S. nigrum) demonstrated functional conservation across Solanaceae species. These findings document a conserved acylsugar transport mechanism and establish ABCB5 as a target for engineering enhanced insect resistance in Solanaceae crops.
Species Mentioned
The tomato is a plant whose fruit is an edible berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originated from western South America, and may have been domesticated there, in Mexico, or in Central America. Th...
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