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Himetobi P virus (HiPV) is an ssRNA in the family Dicistroviridae that infects rice pests belonging to Hemiptera. To determine its host range, a nested PCR method was designed to detect HiPV in some of the main rice pests (Hemiptera) in eastern China. The incidence of infection in the grain aphid Sitobion avenae Fabricius (Hemiptera: Aphididae) was low (3%), while high incidences of infection occurred in the planthoppers Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) (100%) and Nilaparvata lugens (Hemiptera: Delphacidae) (51%) and in the leafhoppers Cicadella viridis (Hemiptera: Cicadellidae) (90%) and Nephotettix cincticeps (Hemiptera: Cicadellidae) (57%). Phylogenetic analysis by maximum likelihood tree and median-joining networks implied the HiPVs from the same hosts were genetically close. Neutral equilibrium evolution for the polymorphism data was tested by the Tajima's D test and by Fu and Li's D and F tests. Test values were negative, which indicates a selection on the HiPV haplotypes. We sequenced the complete genome sequence of HiPV to look for evidence of recombination. We identified a recombination event in which two genomes recombined in the region of ORF2. The two open reading frames of the HiPV had been selected with low Ka/Ks ratios compared with two previous genome sequences., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Thirteen nodule-specific or nodule-enhanced genes have been revealed by suppressive subtractive hybridization (SSH) with two mRNA populations of infected and uninfected control roots of Astragalus sinicus. Eleven of them encode small polypeptides showing homology to cysteine cluster proteins (CCPs) that contain a putative signal peptide and conserved cysteine residues. Among these CCP-like genes, AsG257 codes for a homologue of the defensin 2 family and AsD255 contains a scorpion toxin-like domain at the C-terminus. Sequence analysis of a genomic AsD255 fragment which was isolated revealed that one intron separates the first exon encoding the signal peptide from the second exon encoding the cysteine cluster domain of this nodulin. Another two genes, AsE246 and AsIB259, encode two different products similar to lipid transfer proteins (LTPs). Virtual northern blot and reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that the other genes except AsIB259 and AsC2411 were expressed exclusively in inoculated roots and that their expression was 2-4 d later than that of the leghaemoglobin (Lb) gene during nodule development. Transcription of AsIB259 was also detected in uninfected control roots but with a significant decline in expression and a temporal expression similar to Lb. AsC2411 had a basal expression in control roots identified by RT-PCR. Sequence alignment showed that the putative proteins AsE246 and AsIB259 show lower homology with LTPs from legumes than with those from other plants.