Communities of endophytic microorganisms in different developmental stages from a local variety as well as transgenic and conventional isogenic hybrids of maize

Abstract

The diversity of endophytic microorganisms may change due to the genotype of the host plant and its phenological stage. In this study we evaluated the effect of phenological stage, transgenes and genetic composition of maize on endophytic bacterial and fungal communities. The maize populations were composed of a local variety named Rosado (RS) and three isogenic hybrids. One isogenic hybrid was not genetically modified (NGM). Another hybrid (Hx) contained the transgenes cry1F and pat (T1507 event), which provide resistance to insects of the order Lepidoptera and tolerance to the glufosinate-ammonium herbicide, respectively. The third hybrid (Hxrr) contained the transgene cp4 epsps (NK603 event) combined with the transgenes cry1F and pat (T1507 event), which allow tolerance to the Roundup Ready herbicide, besides the characteristics of Hx. Evaluation of the foliar tissue was done through PCR-DGGE analysis, with specific primers for bacteria and fungi within four phenological stages of maize. The endophytic bacteria were only clustered by phenological stages; the structure of the fungal community was clustered by maize genotypes in each phenological stage. The fungal community from the local variety RS was different from the three hybrids (NGM, Hx and Hxrr) within the four evaluated stages. In the reproductive stage, the fungal community from the two transgenic hybrids (Hx and Hxrr) were separated, and the Hxrr was different from NGM, in the two field experiments. This research study showed that the genetic composition of the maize populations, especially the presence of transgenes, is the determining factor for the changes detected in the endophytic fungal community of maize leaves.

Risk assessment of genetically engineered plants that can persist and propagate in the environment

“…transgenesis and genome editing), and experience shows that interactions with the environment known from conventional plant breeding cannot simply be extrapolated to GE plants. For example, da Silva et al [82] and Wallace et al [83] show differences in the associated microbiomes of transgenic plants are not only influenced by the environment but to some extent also impacted by plant genetics. Therefore, ERA of GE organisms should include potential (intended and unintended) changes of these signalling pathways since they can substantially disturb or even disrupt the functions of the ecosystems.…”

Endophytic Communities of Transgenic Poplar Were Determined by the Environment and Niche Rather Than by Transgenic Events

“…In addition, host genotypes might influence the microbiome that engages in symbiosis with plants. Silva et al (2014, 2016) found that the decisive factor of changes in the endogenous bacterial, fungal, and archaeal communities of maize was the genotype of the maize plants. Meanwhile, other studies showed that endophytic bacteria from maize, rice, and potato were more susceptible to the different stages of plant development and pathogen exposure (Rasche et al, 2006; Janpen et al, 2009; Inceoğlu et al, 2010; Rangjaroen et al, 2014).…”

Limits of Knowledge and Tipping Points in the Risk Assessment of Gene Drive Organisms

“…To some extent, life forms can only be assessed in combination with their environment: for example, the well-established concept of the 'holobiont' (see for example Richardson 2017) shows that multicellular organisms such as plants, insects or mammals can hardly be separated from their associated microbiome. The organism and its associated microbiome interact very closely: it is known that the microbiome can extensively impact the biological characteristics and health status of humans, plants and animals (see for example Lynch and Pedersen 2016;da Silva et al 2016).…”