Expression of Phytase gene in transgenic maize with seed-specific promoter 27-kDa γ Zein and constitutive promoter CaMV 35S

Phytase enzymes are applied to animal feed to help animals absorb more nutrients. The use of feed raw materials containing phytase enzymes is expected to reduce the cost of animal feed production. Efforts to increase the phytase content in maize were carried out by improving genetics, in the way of assembling transgenic plants containing high phytase content. The 27-kDa γ Zein promoter is a specific promoter that expresses genes in caryopsis, and promoter CaMV 35S is a constitutive promoter that controls gene expression in all tissues and generally does not depend on the growth phase. Transgenic maize was transformed using Agrobacterium tumefacien infection method on maize B104. The reverse transcriptase polymerase chain reaction (RT-PCR) approach was used to examine the expression of phytase genes in leaves, roots, and caryopsis was done 10, 20, and 30 days after pollination (DAP). The phytase enzyme activity test was also carried out by using the colorimetric phosphomolybdate analysis method to see the phytase enzyme activity in unit µg-1. The results showed that the phytase gene in transgenic plants with the 27-kDa γ Zein promoter was highly expressed in maize caryopsis, but in line Z6.10 was also expressed in leaves, while in the CaMV 35S promoter the phytase gene was only expressed on the leaves. Phytase enzyme activity showed that transgenic maize was higher than non-transgenic maize.

Novel Plantibodies Show Promise to Protect Citrus from Greening Disease

Candidatus Liberibacter asiaticus (CLas), the bacteria responsible for citrus greening disease [huanglongbing (HLB)], has become a worldwide threat to citrus (Citrus sp.) production. HLB has proven difficult to study and treat because of the complex interactions between CLas, the citrus host, and insect vectors. We have selected for single chain fragment variable (scFv) antibodies from a specialized bacteriophage library for binding activity against CLas proteins InvA and TolC. Portions of each protein were chosen as antigens based on predicted binding availability and theorized necessary functions in pathogenicity. Binding affinity for individual scFv-expressing clones was confirmed by phage enzyme-linked immunosorbent assay (ELISA). The scFv sequences were stably transformed under the control of a tandem Cauliflower mosaic virus 35S (CaMV 2x35S) promoter by Agrobacterium tumefacien–mediated transformation into ‘Carrizo’ citrange (Citrus sinensis × Poncirus trifoliate), a citrus rootstock cultivar. Replicated plants of single transformations were inoculated by infestation with CLas positive asian citrus psyllid (Diaphorina citri), a CLas vector. Inoculation and disease progression was monitored through quantitative real-time polymerase chain reaction. Inoculated transgenic plants showed significantly reduced CLas titer compared with wild types. A subpopulation of transgenic plants displayed no measurable surviving bacteria after 12 months. Interestingly, individual replicated plants from the same transgenic events strongly segregated into two populations by resistance phenotype: a minority that were indistinguishable from wild-type plants and a majority that were highly resistant. Our results are the first step in developing a novel protection strategy for HLB.

Studies on Transformation of Alfalfa with Chicken β-Defensin Gal-3

Chicken β-defensin Gal-3 was recently identified member of a family of antimicrobial peptides. In this paper, the sequences of the chicken β-defensin Gal-3 gene was replaced with plant preferred codons by Polymerase Chain Reaction, and cloned into the plant expression vector p1390R, then transferred into alfalfa by Agrobacterium tumefacien- mediated method. PCR was performed by using the genomic DNA of transgenic alfalfa as template, which showed that Gal-3 has been transferred into alfalfa. Therefore, the suitable concentration of Hyg for screening transformants was 20 mg/L. The 4 trangenic plants were analyzed by Southern hybridization.