White fringetree is a host for the invasive emerald ash borer (EAB) but is of lower quality than the related and highly susceptible black ash. Field observations suggest that host trees grown in full sun are more resistant to EAB than those in shade, however the impact of light limitation on chemical defenses has not been assessed. We quantified constitutive and jasmonate-induced phloem defenses and growth patterns of white fringetree and black ash under differential light conditions and related them to EAB larval performance. White fringetree had significantly lower constitutive and induced activities of peroxidase, polyphenol oxidase, β-glucosidase, chitinase and lignin content, but significantly higher gallic acid equivalent soluble phenolic, soluble sugar, and oleuropein concentrations compared to black ash. Multivariate analyses based on tissue chemical attributes displayed clear separation of species and induced defense responses. Further, EAB performed significantly worse on white fringetree than black ash, consistent with previous studies. Light limitation did not impact measured defenses or EAB larval performance, but it did decrease current year growth and increase photosynthetic efficiency. Overall our results suggest that phenolic profiles, metabolite abundance, and growth traits are important in mediating white fringetree resistance to EAB, and that short-term light limitation does not influence phloem chemistry or larval success.

白条纹树是侵入性祖母绿灰bore（EAB）的宿主，但质量比相关的高度易感黑灰低。野外观察表明，在全日照下生长的寄主树比在阴凉处的寄主树更耐EAB，但是尚未评估光限制对化学防御的影响。我们在不同的光照条件下，对白条纹树和黑灰的本构和茉莉酸诱导的韧皮部防御和生长模式进行了量化，并将它们与EAB幼虫的性能相关。白色柳树的过氧化物酶，多酚氧化酶，β的本构和诱导活性明显降低-葡糖苷酶，几丁质酶和木质素的含量，但是与黑灰相比，没食子酸当量的可溶性酚，可溶性糖和橄榄苦苷的浓度明显更高。基于组织化学属性的多变量分析显示了物种的明确分离和诱导的防御反应。此外，与以前的研究一致，EAB在白色条纹树上的表现比黑灰明显差。光照限制不会影响测得的防御能力或EAB幼虫的性能，但确实会降低当年的增长并提高光合效率。总体而言，我们的结果表明，酚类谱，代谢物丰度和生长性状在介导白条纹树对EAB的抗性中很重要，并且短期光限制不会影响韧皮部化学或幼虫的成功。