Impacts of LED light intensity on the transient expression of GUS gene in soybean (Glycine max) with half-seed transformation method

Soybean (Glycine max) is a crop with major economic and food value worldwide.
Soybean plants are constantly improved using biotechnology techniques for better agronomic traits. Agrobacterium-mediated transformation is commonly used to deliver desired genes to the meristem of the half seeds.
However, the efficiency of the gene delivery is low, hindering plant improvement of soybean.
Light promotes meristem growth and is also involved in signaling pathways in plants, especially relating to stem cell activities.
The goal of the present study is to investigate the impact of light intensity during co-culture (transformation) on soybean transformation efficiency.
In general, half-seed explants undergo a co-culture phase with Agrobacterium for five days under light prior to transgenic shoot regeneration.
Transient expression is an effective approach to study transformation product in a short period.
The hypothesis of the present study is that increasing light intensity during co-culture could increase the transient expression percentage of GUS gene.
In this experiment, various light intensities of white LEDs (50, 100, 150, 190 µmol m^‑2 s^‑1) and fluorescent light (100 µmol m^‑2 s^‑1) were implemented on half-seeds during co-culture for five days.
The meristem area of half-seed explants was examined for GUS transient expression by GUS histochemical assay.
The meristem area with distinct blue circles was considered as transient event.
Results indicated that the percentage of GUS transient expression was low under high light intensity during co-culture.
The light intensity of 50 and 100 µmol m^‑2 s^‑1 yielded the highest transient expression percentage, while fluorescent light treatment delivered 10% less of transient expression than white LED at 100 µmol m^‑2 s^‑1. Furthermore, this research outcome justifies investigations of the effects of various light intensities during co-culture on the stable transformation efficiency for different genes of interest.

International Symposium on New Technologies for Sustainable Greenhouse Systems: GreenSys2023

X. Shi, B. Li, R. Hernández

Agrobacterium-mediated, co-cultivation, gene delivery, white LED, fluorescent light

https://doi.org/10.17660/ActaHortic.2025.1426.21