Host plant leaf water

Flanagan L. B., Marshall J. D., and Ehleringer J. R. (1993) Photosynthetic gas-exchange and the stable-isotope composition of leaf water—comparison of a xylem-tapping mistletoe and its host. Plant Cell Environ. 16(6), 623-631. 

Host plant suitability involves various plant characteristics and insect herbivore adaptations as well as modification of both the plant and the insect by abiotic and biotic factors in their commimity. The post-ingestive growth performance of Lepidoptera (and perhaps most other leaf-chewing insects as well) is determined to a large extent by plant chemical quality (i.e., nutrients and allelo-chemics) and can be indexed by leaf water-nitrogen composition. 

In all susceptible varieties but not in resistant cultivars, powdery mildew infection resulted in a significant increase in the amounts of wax present on leaf surfaces (Table 1). This is likely to reflect the response of host plants to the development of water stress following infection but the relationship has not been specifically investigated in the present study. Preliminary evidence for an increase in hydrocarbons in leaves of durum wheat during the development of water stress was obtained in this laboratory by Kameli (1990). Bengston et ah previously reported increases in alkanes, fatty acids and hexacosanol in oat plants subjected to water stress. 

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