image: Tobacco hornworm (Manducta sexta) feeding on the cultivated tomato Solanum lycopersicum. view more
Credit: Image courtesy of Gregg A. Howe.
Researchers report that plant defenses to herbivory in tomato plants can impede the plants' resilience to elevated temperatures. The stresses placed upon plants by a warming climate can be compounded by biotic factors, such as elevated herbivorous insect activity. Gregg A. Howe and colleagues induced leaf wounds in tomato plants, simulating insect herbivory, at control temperatures of 28 °C during the day and 18 °C at night and at elevated temperatures of 38 °C during the day and 28 °C at night to investigate the interplay between the two stresses. Resistance to insect herbivory is promoted by the hormone jasmonate, and the results suggested that the heat-shock protein HSP90 enhanced jasmonate responses. Plant response to heat stress, however, involves regulating the size of stomatal openings on leaves, which can influence water loss as well as evaporative cooling. Plants kept at elevated temperature exhibited stomatal closure after leaf wounding dependent on the jasmonate receptor COI1. The stomatal closure increased leaf temperature and inhibited growth. The effect was reversed in plants that either lacked the COI1 receptor or in which HSP90 had been inhibited. According to the authors, increased insect activity in a warming climate can harm plants' ability to adapt to a warm climate and may exacerbate crop losses.
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Article #19-13885: "Insect herbivory antagonizes leaf cooling responses to elevated temperature in tomato," by Nathan E. Havko et al.
MEDIA CONTACT: Gregg A. Howe, Michigan State University, East Lansing, MI; tel: 517-355-5159; e-mail: <howeg@msu.edu>
Journal
Proceedings of the National Academy of Sciences