Page 120 - PC2019 Program & Proceedings

PLANT CANADA 2019

S25. Production of recombinant subunit vaccine candidates against Bovine Respiratory Disease
pathogen Mannheimia haemolytica as an alternative to antimicrobials
Kaldis, A.; M. Uddin; T. Alexander; R. Menassa
Government of Canada

Bovine Respiratory Disease (BRD), or Shipping Fever, is a multifactorial disease which results in high
economic loss for the North American beef industry. The goal of this project is to produce an oral
vaccine in plants to protect cattle against infection with Mannheimia haemolytica, the predominant
bacterial agent causing BRD, through mucosal immunity. Antigens were chosen and engineered to
consist of important epitopes and immunogenic sites of proteins from M. haemolytica. Gene constructs
were created with an N-terminal Cholera Toxin B element, as a mucosal adjuvant, fused to a modified
virulence factor and a candidate antigen from M. haemolytica. These constructs were transiently
expressed in Nicotiana benthamiana and targeted to various subcellular compartments to determine where
the recombinant protein most abundantly accumulated and how structurally similar it was to the native
protein components. These chimeric antigen fusions were also stably transformed into the Nicotiana
tabacum chloroplast genome and analyzed. The immunogenicity of these candidate antigens is being
tested in mice.

Angelo Kaldis (Angelo.Kaldis@canada.ca)

S26. Controlling the accumulation of secondary metabolites by plants using antisense
oligonucleotides
1
*2
1
Oberemok, V.* ; K. Laikova ; I. Novikov ; N. Galchinsky ; R. Useinov
1
1
1 V.I. Vernadsky Crimean Federal University
2 Research Institute of Agriculture of Crimea
The unmodified antisense oligonucleotides used for the first time in 2008 as contact DNA insecticides
show great promise in the development of additional post-genomic approaches to problems in agriculture.
The use of DNA oligonucleotides, some of which will act as insecticides against target insects, and others
that will manage and improve the targeted biological parameters of cultivated plants, is a promising
direction of research.

Successful management of the synthesis of secondary metabolites by plants was demonstrated in
peppermint (Mentha piperita) using an unmodified antisense DNA fragment of oligoMEP-11 (5'-
ACACTCTTTTG-3'), which is complementary to the mRNA of the menthon reductase that catalyzes the
formation of menthol from menthon. Peppermint leaves were treated with DNA oligonucleotides at a
2
concentration of 50 pmol/cm . Analysis of the composition of the essential oil was carried out 4 days after
the treatment. The menthol content of the oligoMEP-11 group was 2.03 times less than content measured
in the control group (13.12 ± 1.64% versus 6.47 ± 1.04%, respectively; p<0.05). The decrease in menthol
content was accompanied by a significant increase in menthon content compared with control (61.2 ±
1.31% versus 53.5 ± 1.74%, respectively; p<0.05). The oligoYM-11 control fragment (5'-
CGTACGTACGT-3') did not affect the accumulation of menthol or menthon.

The described approach can find its widest application in agriculture for growing essential oil and
medicinal crops.

Volodymyr Oberemok (genepcr@mail.ru)

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