Arbuscular Mycorrhizal Fungal Association in Genetically Modified Drought‐Tolerant Corn

Abstract

The commercial use of genetically modified (GM) plants has significantly increased worldwide. The interactions between GM plants and arbuscular mycorrhizal (AM) fungi are of considerable importance given the agricultural and ecological role of AM and the lack of knowledge regarding potential effects of drought-tolerant GM corn ( L.) on AM fungal symbiosis. This work studied AM fungal colonization in five corn lines growing under two different irrigation regimes (30 and 100% of soil field capacity [SFC]). Four of the lines were GM corn, and two of these were drought tolerant. The experiment was conducted for 60 d in a growth chamber under constant irrigation, after which mycorrhization, corn biomass, and days to plant senescence (DTS) were evaluated. Arbuscular mycorrhizal fungal species of the order were predominant in the soil inocula. At the end of the experiment, all plants showed AM colonization. Mycorrhization was higher at 30% SFC than at 100% SFC. Within the same corn line, the AM fungi produced more vesicles in plant roots under drought stress. Among treatments, DTS varied significantly, and drought-tolerant GM corn lines survived longer than the wild-type corn when maintained at 100% SFC. Corn biomass did not vary among treatments, and no correlations were found between DTS or biomass and mycorrhization. We conclude that overexpression of the gene in corn plants under the experimental conditions of this study did not affect AM fungal infectivity and improved the tolerance of the corn to drought stress.

Crop Rotation and Straw Application Impact Microbial Communities in Italian and Philippine Soils and the Rhizosphere of Zea mays

“…Among the fungi enriched in the Italian MM soil were Leotiomycetes and Glomeromycetes . Members of Leotiomycetes are known as maize endophytes ( Wang et al, 2006 ) and Glomeromycetes are well-known as arbuscular mycorrhizal symbionts of maize, including the enriched genus Entrophospora ( Na Bhadalung et al, 2005 ; Colombo et al, 2017 ). Actually, the genus Entrophospora was enriched in the MM bulk soil rather than in the rhizosphere (Supplementary Table 6B).…”

HD-ZIP Gene Family: Potential Roles in Improving Plant Growth and Regulating Stress-Responsive Mechanisms in Plants

“…The sunflower (Helianthus annuus) Hah-4 gene was overexpressed in the maize plants to elucidate its role in mitigating the drought stress. The study revealed the crucial role of Hah-4 gene in increasing the resistance of maize plants against drought stress without hindering the agronomic traits and colonization of root Arbuscular mycorrhizal fungi activity [61]. The accumulation of ABA in the leaf is significant and plays a key role in maintaining normal plant growth under drought stress [62].…”

Effects of Drought-Tolerant Ea-DREB2B Transgenic Sugarcane on Bacterial Communities in Soil

“…Hamonts et al (2018) demonstrated that sugarcaneassociated bacterial assemblage is primarily determined by plant compartment, followed by other factors such as the growing region and sugarcane variety. Indeed, plant genotype is responsible for some of the variations observed in root microbiomes, suggesting an active role of the host in the establishment of the communities (Colombo et al, 2017). Additionally, we also found a stronger correlation between the relative metrics of bacterial diversity and environmental factors in TG compared with those in WT, especially for the TC and TN contents ( Figures 1C,D, 2B), suggesting that the changes in the soil environment of the root microbiome influence the bacterial community diversity.…”