Infectious bronchitis (IB) is one of the major diseases in poultry flocks all over the world caused by infectious bronchitis virus (IBV). In the study, the complete genome sequence of strain A2 was sequenced and analyzed, which was a predominant IBV strain in China. The results indicated that there were mutations, insertions, and deletions distributed in the whole genome. The A2 virus had the highest identity to S14 and BJ in terms of full genome, whereas had a further distance to Massachusetts strains. Phylogenetic analysis showed that A2 isolate clustered together with most Chinese strains. The results of this study suggest that strain A2 may play an important role in IBV's evolution and A2-like IBVs are predominant strains in China.

Trichomes are specialized epidermal cells that are commonly present on leaves, stems, and sepals of plants. They are suggested to provide a first line of defense against invading pests and pathogens. By differential display reverse transcription (DDRT)-polymerase chain reaction (PCR) and reverse Northern analysis, an Arabidopsis thaliana gene, AtTSG1, has been identified from epidermal cells of leaves, and found to be specifically expressed in the epidermis. Following BLAST analysis, it is found that this gene encodes a putative translational activator protein, At1G64790, with similarity to HsGCN1. A 1.3-kb promoter sequence of the AtTSG1 gene has been cloned. This promoter is shown to direct the specific expression of the reporter uidA gene, β-glucuronidase (GUS), in trichomes of leaves and stems of Arabidopsis plants. Promoter deletion analysis has revealed that the region from ×300 bp to ×1 bp is sufficient to direct trichomespecific expression, and that a novel cis-acting element to direct trichome-specific expression is involved in the region from ×250 bp to ×200 bp. The AtTSG1 promoter sequence from ×100 to ×1 bp likely contains an initiator (Inr) sequence as a core promoter element to mediate the same function as that of a TATA element. As this AtTSG1 promoter is associated with trichomes, it may provide an efficient bioengineering element for enhancing pest and pathogen resistance in transgenic plants.