Sprecher
Beschreibung
Leaf mining is a specialized feeding strategy in which insect larvae inhabit and feed on the internal tissues of leaves. This strategy not only improves feeding efficiency but also provides natural protection against environmental stressors. For host plants, leaf mining can lead to increased water and nutrient loss and reduced photosynthetic efficiency. In response to these threats, plants have evolved chemical defense strategies to resist herbivory. Fossil leaves with leaf-mining damage provide critical insights into ancient plant-insect interactions; however, the impact of leaf mining on fossil leaf chemistry remains largely unexplored. In this study, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) was used to analyze the chemical composition of ginkgophyte leaves with leaf mining damage from the Upper Triassic Xujiahe Formation in the Sichuan Basin, Southwest China. Due to the scarcity of insect damage on the leaves of Ginkgo biloba, the leaves of the common ivy (Hedera nepalensis) were selected as a modern reference. Modern results show that mined leaf portions exhibit significant chemical differences from unmined portions, containing higher relative contents of carboxylic acids and polysaccharides, indicating that leaf miners manipulate plant physiology while inducing localized host defenses. In the fossil ginkgophyte leaves, both mined and unmined portions display similar chemical defense-related characteristics, suggesting that leaf mining induced a systemic defense response in this Triassic ginkgophyte. This study provides direct evidence for chemical defense in a Triassic ginkgophyte plant against leaf miners and demonstrates the feasibility of using chemical analysis to unravel plant defense mechanisms in deep time.