Abstract
The spr2 mutation in tomato (Solanum lycopersicum), which disrupts function of FATTY ACID DESATURASE 7 (FAD7), confers resistance to the potato aphid (Macrosiphum euphorbiae) and modifies the plant’s C6 volatile profiles. To investigate whether C6 volatiles play a role in resistance, HYDROPEROXIDE LYASE (HPL), which encodes a critical enzyme in C6 volatile synthesis, was silenced in wild-type tomato plants and spr2 mutants. Silencing HPL in wild-type tomato increased potato aphid host preference and reproduction on 5-week old plants but had no influence on 3-week old plants. The spr2 mutation, in contrast, conferred strong aphid resistance at both 3 and 5 weeks, and silencing HPL in spr2 did not compromise this aphid resistance. Moreover, a mutation in the FAD7 gene in Arabidopsis thaliana also conferred resistance to the green peach aphid (Myzus persicae) in a genetic background that carries a null mutation in HPL. These results indicate that HPL contributes to certain forms of aphid resistance in tomato, but that the effects of FAD7 on aphids in tomato and Arabidopsis are distinct from and independent of HPL.
Highlights
FATTY ACID DESATURASE 7 (FAD7) is an ω-3 fatty acid desaturase (FAD) that is widely similar in sequence throughout the plant kingdom, and that desaturates 16- and 18-carbon fatty acids with two double bonds (C16:2 and C18:2) to generate fatty acids with three double bonds (C16:3 and C18:3) [1,2]
We developed a tomato line that is deficient in both FAD7 function and HYDROPEROXIDE LYASE (HPL) expression in order to determine if loss of function of HPL would compromise aphid resistance associated with spr2
A transgenic line in which expression of HPL was targeted for silencing by RNA interference (RNAi) [21] was utilized for this study
Summary
FATTY ACID DESATURASE 7 (FAD7) is an ω-3 fatty acid desaturase (FAD) that is widely similar in sequence throughout the plant kingdom, and that desaturates 16- and 18-carbon fatty acids with two double bonds (C16:2 and C18:2) to generate fatty acids with three double bonds (C16:3 and C18:3) [1,2]. The suppressor of prosystemin-mediated responses (spr2) mutant in tomato, which has a null mutation in FAD7, has enhanced resistance to potato aphids (Macrosiphum euphorbiae) compared to wild-type plants [10]. Population growth of the green peach aphid (Myzus persicae) is significantly lower on Arabidopsis thaliana mutants with null mutations in FAD7 than on wild-type controls [10]. These results indicate that the FAD7 enzyme or its products negatively regulate aphid resistance in more than one plant family
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
