Sequence analysis of RTD at nucleotide and amino acid levels revealed
a high identity (91.8–97.2% and 91.4–100% respectively) between Iranian and other available isolates in the GenBank. However, in regards to ORF1, a high genetic diversity among Iranian and other known PAV isolates at both amino acid (2–16.9%) and nucleotide (4.1–16.5%) levels were detected. Based on phylogenetic analysis of ORF1, two major groups of BYDV-PAV isolates Ibrutinib chemical structure were distinguished. The Iranian isolates were divided between the two clusters. Our results suggest that the occurrence of two genetically distinct groups of PAV isolates in central and southern Iran, from which according to the ICTV criteria for species demarcation in the family Luteoviridae, four isolates from central parts of the country, qualify for designation as new species. “
“RNA-dependent RNA polymerase (RDR-1) is known to be induced by salicylic acid and is involved in basal resistance in plants against pathogen infection. Transgenic lines of tobacco plant (Nicotiana tabacum cv. Samsun NN) variably silenced for RDR-1 gene were assayed for peroxidase (POX) activity following
a systemic infection with Potato virus Y strain O (PVYo). Guaiacol-POX specific activity increased more than twofold in un-inoculated upper leaves of susceptible tobacco lines silenced for RDR-1, 30 days after inoculation with PVYo relative to the wild type. The number and intensity of POX isozymes in intercellular fluid of leaves showing systemic symptoms varied among the transgenic lines. Transgenic selleck chemicals line R-5-1 susceptible to PVYo infection with much lower accumulation of RDR-1 transcript showed two new POX activity bands compared to R-14-1 line that is moderately suppressed this website for RDR-1. Using semi-quantitative RT-PCR, RDR-1, MYB1 (transcription factor) and PVYo RNA accumulation levels were assessed. Transgenic lines with a greater degree of susceptibility to the virus infection
exhibited lower levels of transcript accumulation for both RDR-1 and MYB1 genes. These results suggest that down-regulation of RDR-1 transcript can lead to an alteration in expression pattern of defence-related genes such as POX and MYB1 and enhanced accumulation of PVYo in tobacco plants. “
“Bacterial blight (BB) is one of the major diseases that affect rice productivity. In previous studies, BB resistance was transferred to cultivated rice Oryza sativa from wild rice Oryza meyeriana using asymmetric somatic hybridization. One of the resistant hybrid progenies (Y73) has also been shown to possess novel resistance gene(s) different from any of those previously associated with BB resistance. We have mapped quantitative trait loci (QTLs) for BB resistance in a recombinant inbred line (RIL) population derived from a cross between Y73 and a BB-susceptible cv. IR24.