Allium Sativum Leaf Agglutinin (ASAL) Endowed Enhanced Resistance Against Myzus Persicae under Both Constitutive and Phloem Specific Promoters

Globally, aphid, Myzus persicae is an economically significant, polyphagous crop pest that feeds on more than 400 plant species and transmits more than 100 plant viruses. Aphid infestation is mostly managed by insecticides that cause heavy environmental contamination and insect resistance. Cloning of plant derived insecticidal genes to develop transgenic plants under suitable promoter is a promising technology. In the present study, ASAL (MN820725) was isolated from native garlic and cloned in plant transformation vector, pGA482 through Agrobacterium mediated tobacco transformation. PCR of genomic DNA of transgenic tobacco plants using gene specific primers confirmed the presence of asal gene of 546 bp. To detect the integration of gene Southern blot analysis was conducted that revealed stable integration of asal gene while, gene expression was analyzed through qRT-PCR that showed variable expression of asal gene in transgenic tobacco plants. Efficacy of asal gene was evaluated through aphid bioassay. Aphid bioassay revealed that transgenic tobacco lines LS-17, LS-20, LR-1, and LR-7 exhibited 100% aphid mortality and significantly reduced the aphid population. These findings suggested the potential of ASAL against aphids that can be further used against other notorious sap sucking pests.

No Evidence of Unexpected Transgenic Insertions in T1190 – A Transgenic Apple Used in Rapid Cycle Breeding – Following Whole Genome Sequencing

Rapid cycle breeding uses transgenic early flowering plants as crossbreed parents to facilitate the shortening of breeding programs for perennial crops with long-lasting juvenility. Rapid cycle breeding in apple was established using the transgenic genotype T1190 expressing the BpMADS4 gene of silver birch. In this study, the genomes of T1190 and its non-transgenic wild-type PinS (F1-offspring of ‘Pinova’ and ‘Idared’) were sequenced by Illumina short-read sequencing in two separate experiments resulting in a mean sequencing depth of 182× for T1190 and 167× for PinS. The sequencing revealed 8,450 reads, which contain sequences of ≥20 bp identical to the plant transformation vector. These reads were assembled into 125 contigs, which were examined to see whether they contained transgenic insertions or if they are not using a five-step procedure. The sequence of one contig represents the known T-DNA insertion on chromosome 4 of T1190. The sequences of the remaining contigs were either equally present in T1190 and PinS, their part with sequence identity to the vector was equally present in apple reference genomes, or they seem to result from endophytic contaminations rather than from additional transgenic insertions. Therefore, we conclude that the transgenic apple plant T1190 contains only one transgenic insertion, located on chromosome 4, and shows no further partial insertions of the transformation vector.Accession Numbers: JQ974028.1.

Standardisation of an Agroinfiltration Protocol for Eggplant Fruits and Proving its Usefulness by Over-expressing the SmHQT Gene

Eggplant is a fruit vegetable of family Solanaceae, and eggplant fruits are of different shape and sizes that render them as an ideal system for metabolic engineering. Here, we have developed an agroinfiltration protocol for the transient expression of a gene in the eggplant fruit using GUS bearing; pCAMBIA1304 vector. Thereafter, to prove the effectiveness of the developed protocol, we have used the eggplant hydroxycinnamoyl CoA-quinate transferase (SmHQT), which is the central enzyme studied to increase the chlorogenic acid content, in a gene construct with the specific promoter in a plant transformation vector (pBIN19). Also, in our cassette, we also co-expressed the P19 protein of Tomato bushy stunt virus (native promoter) to overexpress the protein. Overall, using the protocol, the chlorogenic content was increased by more than two folds in the transgenic tissues.

Gene Stacking for Fungal Resistance in Plant Transformation Vector

ABSTRACT: Fungal diseases like early blight, late blight, fusarium wilt cause 30-40 per cent loss in fruit production. Form past decade many transgenic plants had been developed using genes encoding chitinases and glucanases with the objective of imparting fungal disease resistance. Since the genes encoding chitinase and glucanase act synergistically. The study was performed to construct plant transformation vector pRAGS carrying both ech42 and bgn under single T-DNA region. Initially, HindIII site at 5' end of earlier cloned bgn (T. harzianum) was removed using primers during reamplification of the gene. The amplicons were cloned into pTZ57R/T containing T overhangs at Eco321 site and transferred to E. coli DH5a and further to plant transformation vector pBI121 which was named as pRA121. In order to clone another gene (ech42) into pRA121, expression cassette from iHP vector was transferred to pRA121 and named as pRAG121. Further in order to gain XhoI site for cloning ech42 gene into pRAG121, ech42 (pSUM1) was cloned into pYES2/CT, named as pSAG1, ech42 from pSAG1 cloned with KpnI and XhoI in pRAG121 and named as pRAGS121. The vector constructed in the present study can be used to transform important crop plants to have enhanced resistance to fungal diseases.

Transformation of Antisense Chalcone Synthase (CHS) Gene into Lotus (Nelumbo Nucifera Gaertn.) by Particle Bombardment

Chalcone synthase (CHS) is a key enzyme in the flavonoid biosynthesis pathway. CHS genes were cloned from genomic DNA and cDNA from the petals of 'Buntharik' white lotus and 'Sattabangkacha' pink lotus by the PCR technique using a specific primer of the CHS gene designed from the GenBank database. Semi-quantitative RT-PCR analysis revealed that the highest CHS gene expression was found in the early budding stage of the pink lotus and was reduced in later stages. Shoot tips from embryos of Buntharik and Rachinee lotus were used to induce shoot clusters by cultivation on a MS medium supplemented with 40 µM NAA and 0.5 µM TDZ for 8 weeks and a MS medium supplemented with 50 µM BA for 8 weeks. An antisense CHS gene (450 bp) from the cDNA of Buntharik lotus was used to construct a plant transformation vector; pCAMBIA1302CHSA. The vector construct was transformed into Buntharik and Rachinee shoot clusters by particle bombardment. After transformant selection and regeneration, two transformants of Buntharik shoot clusters showed GFP green spots and existence of the GFP gene and hptII gene in the genomic DNA amplified by the PCR technique. In the Rachinee transformants, 3 of 5 showed the GFP green spots and the GFP and hptII genes were identified in amplification by PCR. After CHS gene expression analyses by semi-quantitative RT-PCR, two transformed Rachinee shoot clusters had a reduction in CHS gene expression.

A Human Anti-Pseudomonas aeruginosa Serotype O6ad Immunoglobulin G1 Expressed in Transgenic Tobacco Is Capable of Recruiting Immune System Effector Function In Vitro

ABSTRACT The production of a recombinant human IgG1 in transgenic tobacco was examined to determine whether a plant-derived antibody could recruit immune system effector function against a bacterial pathogen. A plant transformation vector was engineered to contain genes for a human kappa light chain and a human gamma-1 heavy chain with VH and VL sequences from a previously identified human IgG2 monoclonal antibody (MAb) that specifically binds to and opsonizes Pseudomonas aeruginosa serotype O6ad. Unique NcoI and NotI restriction sites were incorporated to flank these variable sequences, resulting in a plant transformation vector that could be engineered for expression of any other human IgG1 antibody, requiring only the substitution of other VH and VL antigen-binding coding sequences. The plant-produced IgG1 was determined to have high-mannose glycan content and to be capable of mediating opsonophagocytosis of P. aeruginosa serotype O6ad in vitro using human complement and human polymorphonuclear leukocytes. Thus, MAbs produced in plants from this vector could provide human IgG1 MAbs for targeting other pathogens that require the recruitment of immune system effector functions.