Fitness and Ecological Risk of Hybrid Progenies of Wild and Herbicide-Tolerant Soybeans With EPSPS Gene

Abstract

Exogenous genes of transgenic crops are usually transferred to their wild-type relatives through pollen-mediated gene flow, which may change the ecological fitness and ability to invade wild populations, resulting in the weeding of wild plants and other unpredictable environmental impacts. In this study, the F1 generation of herbicide-resistant soybeans and wild soybeans was obtained by artificial pollination, F2 generation seeds were obtained by self-crossing, and the fitness of the parents and their F1 and F2 generations were tested. The foreign protein EPSPS was expressed normally in the hybrid between transgenic and wild soybeans; however, the protein expression was significantly lower than that in transgenic soybeans. The fitness of the F1 hybrid between transgenic and wild soybeans was significantly lower than that of its parent. Compared with those of the wild soybeans, the F2 generation soybeans improved in some fitness indices, while the emergence rate, pollen germination rate, and number of full seeds per pod, pods per plant, and full seeds per plant did not significantly differ. The aboveground biomass and 100-seed weight of the F2 generation were higher than those of wild soybeans. Fitness among the F2-negative plants, homozygous, and heterozygous positive plants did not significantly vary. Improved fitness and presence of foreign genes in the F2 soybean were not significantly correlated. As the F2 generation of transgenic and wild soybeans had no fitness cost and the flowering stage were overlapped, the foreign gene might still spread in the wild soybean population.

In Situ Proteomic Analysis of Herbicide-Resistant Soybean and Hybrid Seeds via Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging

“…With wild soybean as the progenitor, many cultivated soybean varieties have been developed for adaptation via breeding to increase crop yield and seed quality through improved adaptability in different environments . Due to the long-term artificial selection and domestication, the seed of cultivated soybean has distinct seed protein composition and characteristics compared to the wild soybean . According to the results of the PCA, the protein composition of F 2 seeds showed intermediate characteristics of the parent soybeans, which is in line with soybean inheritance.…”

“…Exogenous-gene-containing F 2 (F 2 ) seeds were detected and selected for this study. The edge of the soybean seed was used for foreign protein detection as per the method described by Liu et al…”

“…From 2019 to 2021, three events, including DBN9004 ( epsps and pat gene), were respectively granted GMO safety certificates in China. Thus, herbicide-resistant soybeans are the most likely to be grown commercially on a large scale in China . During transgenic soybean cultivation, exogenous genes can pose some environmental risks such as the resistance development of target-organisms and gene flow to wild relatives and other cultivated varieties via pollen. , The United States, Brazil, and Argentina, where GM soybeans are grown on a large scale, do not have natural wild soybean populations, as opposed to China, where many grow very close to soybean fields .…”

“…Thus, herbicide-resistant soybeans are the most likely to be grown commercially on a large scale in China . During transgenic soybean cultivation, exogenous genes can pose some environmental risks such as the resistance development of target-organisms and gene flow to wild relatives and other cultivated varieties via pollen. , The United States, Brazil, and Argentina, where GM soybeans are grown on a large scale, do not have natural wild soybean populations, as opposed to China, where many grow very close to soybean fields . Wild soybean has good environmental adaptability as well as salt, drought, and nitrogen stress tolerance, making it essential for the study of soybean evolution. , As cultivated soybean is a domesticated and improved version (Glycine soja, 2 n = 40, GC), the two provide a basis for studying genes under natural versus farmland conditions .…”

“…Gene flow risk assessment focuses on the frequency of transgene escape to related wild species, with only a few studies on the changes in fitness and long-term ecological effects on affected wild species. , Fitness is reflected by vegetative and reproductive growth indicators that determine the viability of hybrids . Currently, studies on the fitness of hybrids between transgenic and wild soybeans have focused on vegetative growth and reproduction indicators, such as above-ground indicators and pod numbers . However, these studies cannot comprehensively assess changes in plant traits.…”