Wounding and cold stress increase resin and rubber production of Parthenium argentatum cultivar G711

Authors: PLACIDO, DANTE - Former ARS Employee; McMahan, Colleen; Lee, Charles

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2022
Publication Date: 12/30/2022
Citation: Placido, D., McMahan, C.M., Lee, C.C. 2022. Wounding and cold stress increase resin and rubber production of Parthenium argentatum cultivar G711. Industrial Crops and Products. 193. Article 116174. https://doi.org/10.1016/j.indcrop.2022.116174.
DOI: https://doi.org/10.1016/j.indcrop.2022.116174

Interpretive Summary: Natural rubber (NR) is a critical component of many essential consumer products, such as automotive tires. Almost all NR used in the US is imported and is collected from tropical Hevea brasiliensis trees. Guayule (Parthenium argentatum) is a very promising alternative source for NR. Guayule is a shrub that grows in the semi-arid Chihuahuan desert of the SW United States. A better understanding of the environmental factors that affect rubber yields in guayule will provide important information for breeders and growers. In this study, we tested the effects of two stresses (wounding and cold growth treatment) upon the plants. We found that plants subjected simultaneously to both wounding and cold growth had the greatest increases in rubber and resin yields. Furthermore, we observed intriguing patterns in the plant phytohormone responses that suggest additional treatments to investigate in future studies.

Technical Abstract: The world’s supply of natural rubber is primarily extracted from tropical Hevea brasiliensis trees and is an essential component of many industrial goods. Guayule (Parthenium argentatum) is a very promising alternative source for natural rubber. Abiotic stresses (cold, drought) can increase rubber production in guayule. Here, we investigated the impact of wounding and cold on guayule plants under controlled (growth chamber) environments. Physical characteristics of the plant were measured as well as the levels of rubber, resin, and a wide range of phytohormones. There were significant changes in plant architecture, rubber and resin production, and in phytohormone levels when the plants were subjected to wounding and/or cold treatment. The highest rubber and resin production was found for cold + wounding stressed plants, where stem jasmonic acid concentration was at the lowest level. Results suggest that jasmonic acid and salicylic acid respond to abiotic stress antagonistically in guayule, and further, play a significant role in stress-induced rubber biosynthesis.