Field Supervisory Test of DREB-Transgenic Populus: Salt Tolerance, Long-Term Gene Stability and Horizontal Gene Transfer

Abstract

Improving saline resistance may be useful for reducing environmental susceptibility and improving yields in poplar plantations. However, the instability of genetically engineered traits and gene transfer reduce their usefulness and commercial value. To investigate whether the foreign gene is still present in the genome of receptor plants after seven years (i.e., long-term foreign gene stability and gene transfer), we randomly analyzed ten field-grown transgenic hybrid Populus ((Populus tomentosa × Populus bolleana) × P. tomentosa) carrying the DREB1 gene from Atriplex hortensis. The results of PCR and tissue culture experiments showed that AhDREB1 was present in the transgenic trees and was still expressed. However, the transcriptional expression level had decreased compared with that four years earlier. The PCR results also indicated no foreign gene in the genomic DNA of microorganisms in the soil near the transgenic poplars, indicating that no OPEN ACCESSForests 2014, 5 1107 significant gene transfer had occurred from the transgenic poplars to the microorganisms at seven years after planting.

Reproductive modification in forest plantations: impacts on biodiversity and society

“…In some cases, the improvements can be substantial, such as elevating productivity in the field by c . 20% in poplar (Klocko et al ., ; Lu et al ., ; Ault et al ., ). However, the movement of seeds and pollen from GE plantations to feral and wild populations (hereafter termed ‘gene flow’) has been highly contentious in its regulatory treatment, public acceptance and possible impacts on markets.…”

“…A large body of field research has shown that GE methods appear capable of delivering improvements to plantation productivity, wood processing, pest resistance or chemical products (FAO, 2010;H€ aggman et al, 2013; Table 1). In some cases, the improvements can be substantial, such as elevating productivity in the field by c. 20% in poplar (Klocko et al, 2014;Lu et al, 2014;Ault et al, 2016). However, the movement of seeds and pollen from GE plantations to feral and wild populations (hereafter termed 'gene flow') has been highly contentious in its regulatory treatment, public acceptance and possible impacts on markets.…”

An Assessment of the Environmental Impacts of Transgenic Triploid Populus tomentosa in Field Condition

“…The field trial started in 2005 and the field conditions were presented previously [15]. The experimental field was located in Dongying, Shan Dong Province, China (36 • 56 N, 118 • 17 E), and the annual average temperature, rainfall, amount of sunshine, and evaporation were 12.3 • C, 597 mm, 2590.1 h, and 2032 mm, respectively.…”

“…Because tree species are commonly perennial and have longer lifespans, longer biodegradation, greater potential for long-distance dispersal of pollen and seeds, and greater size than crops and other annual plants, the potential impact of transgenic trees on the environment may be more substantial and continuous [13]. To date, many biosafety studies and field supervisory tests for genetically modified plants have been conducted [1,14,15].…”

“…The expression of this transgene improves the salt tolerance of receptor trees significantly by regulating multiple salinity and alkali stress resistance-related genes. Such trees have been cultivated in the field since 2005 [15]. Based on the experience and knowledge obtained from a previous trial, we assessed the effects on soil microorganisms, pollen fertility, persistence of DNA in decomposing leaves, and allelopathic activity.…”