Continuous exposure of low-toxic gossypol cotton to pests and diseases under semi-field conditions shows no difference from non-edited cotton
摘要
Gossypol is a significant metabolite in cotton, serving as a crucial component of plant defense. However, seed cake containing gossypol has toxic effects when used as animal feed. The CRISPR-Cas system has been used to mutate genes involved in synthesis of toxic gossypol, and seeds were found to have no toxic effects on animals. However, the long-term impact of reduced toxic gossypol levels in cotton plants on insect infestation is unknown.
ResultsWe exposed toxic gossypol-edited and non-edited cotton plants to a natural infestation of insect pests, with no pesticides used to control. The data were recorded for three years, i.e., 2023−2025. Pest abundance varied with no consistent increase in infestation in edited and non-edited cotton lines. Jassid densities were equivalent in 2023 (1.62 and 1.62 mean counts), while it increased in 2025 with a slight increase in non-edited lines, i.e., 3.12 and 5.25 mean counts. Whitefly populations remained low during 2023 and 2024 (≤ 0.50 individuals per plant), with a slight rise in 2025 (2.00 edited and 2.75 non-edited). Mealybug incidence was negligible in 2023–2024, with a uniform increase in 2025 of 2.25 in both lines. These findings indicated no enhanced pest susceptibility in the edited genotype. We did not find any significant differences in pest infestation of mealybug (P = 0.647) and whitefly (P = 1.000) in edited and non-edited lines.
ConclusionEdited and non-edited lines of cotton sustained equal pest pressure, without increased susceptibility in the edited lines that specific toxic gossypol was eliminated from the cotton seed. These findings validate the defensive traits of cotton plants and support the application of such traits in future gene-edited field crops for food and forage crop lines as previously reported in the USA according to the guidelines of the Food and Drug Administration.