Development of transgenic tobacco lines with pyramided insect resistant genes

Abstract

Insect pests are among the major constraints rendering drastic decreases in crop yield. The expression of stacked insecticidal genes in crops can lead to resistance durability and can delay the development of resistance in target insect pests. The present study was designed to introduce an insect resistance trait in locally cultivated Turkish tobacco cultivars (Basma and Nail) with pyramided insecticidal genes. Agrobacterium strain LBA4404 harboring plasmid pKGH4 with cry1Ac and cry2A genes under the control of 35S promoter was used to infect leaf discs of both cultivars; plasmid also contained uidA within the T-DNA region for earlier screening of putative transformants. The overall transformation efficiency was calculated as 30.7% and 18.8% in Basma and Nail, respectively. PCR results confirmed the integration of cry1Ac, cry2A, uidA, and nptII genes in 40 plants of Basma and 16 plants of Nail. ELISA results showed variation in expression of cry1Ac protein among transgenic plants varying from 0.017 to 0.607 µg/g of fresh tissue. Bioassay results with potato tuber moth (Phthorimea operculella Zeller) showed significant mortality of the targeted pest on primary transformants. Furthermore, T1 transgenic progeny exhibited the inheritance of T-DNA in Mendelian as well as non-Mendelian fashion. The results revealed that lines can serve as a source of germplasm in tobacco breeding programs.

An effective pest management approach in potato to combat insect pests and herbicide

“…According to them, a unique digestive proteolytic system is found in growing stages of CPB which became more active during greater instars. As activity of cry1Ac toxin is already been reported against lepidopterans (Selale et al 2017;Bakhsh et al 2018); therefore, higher mortality rates of PTM were recorded in our studies which are in agreement with earlier reports by Veale et al (2012), Estrada et al (2007) and Davidson et al (2004).…”

“…35S-P3 transgenic plant showed more than eightfold expressions as compared to others; overall expression levels were different among transgenic plants that can be attributed to different transformation events in different transgenic plants. The nucleotide sequence of the gene or the insertion point of the gene in the DNA of the transgenic variety, transgene copy number, and other related factors (Rao 2005;Bakhsh et al 2018). Furthermore, it also led to varied cry protein expression among transgenic plants.…”

Development of Efficient, Reproducible and Stable Agrobacterium-Mediated Genetic Transformation of Five Potato Cultivars

“…The scientific literature reports the use of Agrobacterium -mediated genetic transformation system for the introduction of gene(s) encoding traits of economic importance in crop plants ( 17 , 18 ). Agrobacterium tumefaciens strain LB4404 has been found more infective and efficient than other strains for transformation especially in dicots ( 19 ).…”

“…Some of the cultivars are more amenable to transformation than others. Various factors, such as the type of vector and Agrobacterium strain, explant type, and varietal genetic background can affect the efficiency of Agrobacterium -mediated transformation in crops ( 9 , 12 , 18 , 19 , 24 ). The putative transgenic plants (210 in total number) of different cultivars were acclimatized to the greenhouse and confirmed by PCR assays.…”