ABSTRACT
Ten purified crystal proteins of Bacillus thuringiensis (Bt) were tested at concentrations ranging from 2.93 to 3000ng/cm(2) for their toxicity to eri silkworm through protein paint bioassays using castor leaves. Based on LC50 values, Cry1Aa (2.6ng/cm(2)) was highly toxic followed by Cry1Ac (29.3ng/cm(2)) and Cry1Ab (68.7ng/cm(2)). The Cry1Ca and Cry1Ea proteins were moderately toxic to eri silkworm larvae and resulted in 23% and 28% mortality, respectively at the highest concentration tested (3000ng/cm(2)). Only reduction in larval weight was observed with Cry2Aa, Cry1Da and Cry9Aa proteins while Cry3Aa and Cry1Ba proteins were found to be nontoxic.
Subject(s)
Bacterial Proteins/toxicity , Bombyx , Endotoxins/toxicity , Hemolysin Proteins/toxicity , Pest Control, Biological/methods , Animals , Bacillus thuringiensis Toxins , InsecticidesABSTRACT
Identification of genes expressed during the Golovinomyces orontii infection process in Helianthus niveus assumes importance for incorporation of resistance to powdery mildew in cultivated sunflower (H. annuus L.) from this donor species. RNA-seq analysis of control (uninfected) and infected samples of H. niveus resulted in identification of 231,754 transcripts. A total of 3726 transcripts were differentially expressed of which 205 were specifically expressed in control and 1961 in infected samples. Functional annotation of the differentially expressed transcripts showed significant upregulation of GRAS type transcription factor (TF) and plant specific GATA-type zinc finger TF in infected samples and the K-box, MADS box TF and WRKY family TF in control tissues. Gene ontology classification showed that genes involved in cell and cell part functioning, catalytic and metabolic processes were significantly and highly expressed. This is the first application of RNA-Seq for identification of key genes and pathways involved in powdery mildew infection process in a Helianthus species conferring resistance to the pathogen.
ABSTRACT
Particle bombardment/biolistic delivery is a very popular method of genetic transformation of diverse targets including cells and intact tissues. Delivery of DNA through particle bombardment is genotype and species independent, nevertheless, an efficient protocol for large-scale generation of transgenic plants through embryogenic tissues with a high (≥80%) shoot regeneration efficiency is a prerequisite. Young embryogenic tissues or multiple shoot buds in early stages of induction are the most suited target tissues for recovery of transgenic plants. We describe the protocol for delivery of foreign genes using particle delivery system (Biorad gene gun, PDS-1000/He) in to the meristematic tissues of embryonic axes derived from mature seeds of castor. With the optimized physical and biological parameters, putative transformants were obtained at a frequency of 1.4% through particle gun bombardment of castor embryo axes. Also, transformation of embryogenic calli of sorghum using particle inflow gun (PIG) is described.