Pulsating drought and insect herbivory cause differential effects on Soybean (Glycine max) genotypes that vary in canopy wilting speed.

Authors: AYALA, JESSICA - University Of Arkansas; GAUTAM, MANISH - University Of Arkansas; PIESSEL, ADRIANA - University Of Arkansas; George, Justin; KARIYAT, RUPESH - University Of Arkansas

Submitted to: Plant-Environment Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2025
Publication Date: 1/30/2025
Citation: Ayala, J., Gautam, M., Piessel, A., George, J., Kariyat, R. 2025. Pulsating drought and insect herbivory cause differential effects on Soybean (Glycine max) genotypes that vary in canopy wilting speed.. Plant-Environment Interactions. https://doi.org/10.1002/pei3.70028.
DOI: https://doi.org/10.1002/pei3.70028

Interpretive Summary: Soybean (Glycine max (L.) Merr) is one of the most important crops in the world due to its importance as food and feed. One of the major limiting factors for soybean production is drought- which can cause up to 80% reduction in yield. Therefore, growers and plant breeders are turning to soybean accessions that demonstrate better water use efficiency (WUE). However, drought is not the only stress that soybeans encounter in the field. Soybean looper (Chrysodeixis includens, SBL) and fall armyworm (Spodoptera frugiperda, FAW), are two herbivores that can significantly reduce soybean yield by feeding on foliar and floral organs. Using soybean accessions that differ in their wilting speed, we examined the relationship between physiological traits associated with WUE and insect resistance traits, and how they affect both herbivore and host plant growth and development. Results showed that both fast and slow wilting soybean genotypes displayed strong overcompensation in terms of growth and development, but slow wilting soybean genotypes produced higher quality pods and seeds. FAW fed at a significantly higher rate than SBL despite being less specialized to feed on soybean plants, regardless of treatment effects. While fast wilting plants produced more pods than slow wilting plants irrespective of treatments slow wilting plants produced heavier pods with larger and heavier seeds. This study showed that in spite of fast wilting soybean plants overcompensating in pod production and growth traits, slow wilting soybean plants may still be better fit through seed functions.

Technical Abstract: As a result of climate change, global temperatures are increasing, and water scarcity is on the rise. Soybean (Glycine max (L.) Merr) is one of the most important crops in the world due to its importance as food and feed. One of the major limiting factors for soybean production is drought- which can cause up to 80% reduction in yield. Therefore, growers and plant breeders are turning to soybean accessions that demonstrate better water use efficiency (WUE). However, drought is not the only stress that soybeans encounter in the field. Soybean looper (Chrysodeixis includens, SBL) and fall armyworm (Spodoptera frugiperda, FAW), and are two herbivores that can significantly reduce soybean yield by feeding on foliar and floral organs. Using soybean accessions that differ in their wilting speed, we examined the relationship between physiological traits associated with WUE and insect resistance traits, and how they affect both herbivore and host plant growth and development. Results showed that both fast and slow wilting soybean genotypes displayed strong overcompensation in terms of growth and development, but slow wilting soybean genotypes produced higher quality pods and seeds. Regardless of treatment effects, FAW fed at a significantly higher rate than SBL despite being less specialized to feed on soybean plants. While fast wilting plants produced more pods than slow wilting plants regardless of treatment, slow wilting plants produced heavier pods with larger and heavier seeds. Collectively, we show that in spite of fast wilting soybean plants overcompensating in pod production and growth traits, slow wilting soybean plants may still be better fit through seed functions.