Genetic Engineering, Efficacy and Environmental Biosafety of Transgenic Pea (Pisum sativum L.)

• Author / Creator

  Kahlon, Jagroop G

• Canada is the world’s largest producer and exporter of field peas (Pisum sativum L.). Plant productivity can be greatly reduced by biotic and abiotic stresses, including fungal diseases and drought. Biotechnological tools are available for enhancing tolerance against these stresses. We developed a putative drought tolerant transgenic pea AC EARLY STAR coexpressing PR10a from potato (Solanum tuberosum L.) and transcription factor DREB2A from rice (Oryza sativa L.) using a dicistronic vector through Agrobacterium mediated gene transformation. Gene expression analysis using RT-PCR was conducted on the PCR positive transgenic plants (with a transformation efficiency of 3.65%). A preliminary drought bioassay under laboratory conditions showed enhanced drought tolerance of the developed transgenic lines compared to non-transgenic lines. T3 generation has been obtained and imported to Canada. In addition, antifungal genes were previously transformed in pea in Germany and tested for their field efficacy in Canada. Transgenic lines with four antifungal genes (1-3 β-1,3 glucanase, endochitinase, polygalacturonase inhibiting proteins and stilbene), were tested for their efficacy against Fusarium root rot and Mycosphaerella blight in two different confined trials over three years (2013 to 2015) and in comparison with two parental German lines and three Canadian lines. , in Edmonton, AB. In both field trials conducted in Alberta over three years, no consistent differences in pattern of superior emergence, higher fresh weight or yield benefit, lower disease ratings between of transgenic lines in presence of pathogen inoculum were as observed when compared to the parental and Canadian lines in the presence of pathogen inoculum. No indication of an advantage of stacked genes over single genes was observed. Most transgenic lines had lower relative gene expression in roots than leaves, suggesting the role of promoters chosen or silencing of genes. Due to concerns about unintended consequences on non-target organisms including beneficial soil associates, pea transformed with four antifungal were tested in confined field trials in 2013, these transgenic to determine the impact of disease tolerant pea or gene products on colonization by non-lines target did not show differences in root colonization by arbuscular mycorrhizae fungius, (AMF) and nodulation by Rhizobium. Transgene insertion, as single gene or stacked genes, did not alter root colonization by AMF or root nodulation by Rhizobium inoculation in the field. We found no effects of transgenes on the plant growth performance were noted, although having a dual inoculant with both AMF and Rhizobium yielded higher shoot-to-root ratio in all the lines tested. Field trials are crucial in testing agronomic and ecological relevance of engineered traits of interest from laboratory studies.

• Subjects / Keywords

  • Risk assessement
  • Mycosphaerella blight
  • Transgenic
  • Arbuscular mycorrhizae
  • Fusarium root rot
  • Pisum sativum L
  • Rhizobium
  • Genetically modified

• Graduation date

  Spring 2018

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3X92205B

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.