Diverse Regulations of Viral and Host Genes in Tomato Germplasms Responding to Tomato Yellow Leaf Curl Virus Inoculation

Tomato yellow leaf curl virus(TYLCV)is the dominating pathogen of tomato yellow leaf curl disease that caused severe loss to tomato production in China.In this study,we found that a TYLCV-resistant tomato line drastically reduced the accumulation of viral complementary-sense strand mRNAs but just moderately inhibited that of viral DNA and virion-sense strand mRNAs.However,two other resistant lines did not have such virus inhibition pattern.Analysis of differential expressed genes showed that the potential host defense-relevant processes varied in different resistant tomatoes,as compared to the susceptible line,suggesting a diversity of tomato TYLCV-resistance mechanisms.

Expression Analysis of Restorer Alleles-Induced Genes in Pepper

Fertility restoration of cytoplasmic male-sterility in pepper （Capsicum annuum L.） is useful for commercial production of hybrid seeds. However, the mechanism of fertility restoration has not been determined. We previously constructed a cDNA library and identified some genes related to fertility restoration in pepper using suppression subtractive hybridization technology. In this study, the expression patterns of 20 genes were investigated using semi-quantitative RT-PCR. Three genes expressed only in restorer lines, but not in sterility lines. Four genes expressed only in anther, but not in other organs. Among these 7 genes, the clone TG31 was observed to specifically express in anther of restorer lines. The work described here provides a comprehensive overview on the expression pattern of the genes that are induced by restorer alleles in pepper. It will also contribute to the current understanding of molecular networks for the regulation of fertility restoration.

Investigation on the Association of Soil Microbial Populations with Ecological and Environmental Factors in the Pearl River Estuary

An investigation on the soil microbe populations from an agricultural inning area at the Pearl River estuary in Guangdong province, China was conducted via high through-put sequencing. The results revealed abundant diversity in the soil bacterial and fungal populations. In total, 197103 sequence tags were obtained from soil samples, most of which represented bacterial genera Actinomycetes, Bacillus and Marinobacter, while a majority of 118378 tags obtained were derived from fungal genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, Penicillium, and Emericella. Furthermore, nine physiological indexes (pH, available phosphorous, basic-group nitrogen, available potassium, catalase, sucrose, urease, phosphatase, and organic matters) were measured in three soil samples, and the association between these physiological indexes and microbe population composition was examined. The results revealed obvious inter-sample differences associated with ten dominating microbial groups: genera Clostridium, Devosia, Bradyrhizobium, Bdellovibrio, Phenylobacterium, and Penicillium were mainly impacted by pH (with a positive correlation), genera Sphingomonas and Acinetobacter mainly by available phosphorous (positive correlation), and genera Gemmatimonas and Pseudomonas by both pH and available phosphorous (negative correlation). Our study suggested that regulation of microbial species/populations might help improve soil environment to facilitate the growth of crops’ above-ground parts, and this provides practical information for inning agriculture.