Genome-Wide Analysis of Genes Involved in the GA Signal Transduction Pathway in 'duli' Pear (Pyrus betulifolia Bunge).

Gibberellic acid (GA) is an important phytohormone that regulates every aspect of plant growth and development. While elements involved in GA signaling have been identified and, hence, their functions have been well studied in model plants, such as Arabidopsis and rice, very little is known in pear. We, therefore, analyzed the genes related to GA signaling from the recently sequenced genome of the wildtype 'duli' pear (Pyrus betulifolia Bunge), a widely used rootstock for grafting in pear cultivation in China due to its vigorous growth and resistance to abiotic and biotic stress. In total, 15 genes were identified, including five GA receptors PbGID1s (GA-INSENSTIVE DWARF 1), six GA negative regulators, PbDELLAs, and four GA positive regulators, PbSLYs. Exogenous application of GA could promote the expression of PbGID1s but inhibit that of PbDELLAs and PbSLYs in tissue culture 'duli' pear seedlings. The expression profiles of these genes in field-grown trees under normal growth conditions, as well as in tissue-cultured seedlings treated with auxin (IAA), GA, paclobutrazol (PAC), abscisic acid (ABA), and sodium chloride (NaCl), were also studied, providing further evidence of the involvement of these genes in GA signaling in 'duli' pear plants. The preliminary results obtained in this report lay a good foundation for future research into GA signaling pathways in pear. Importantly, the identification and preliminary functional verification of these genes could guide molecular breeding in order to obtain the highly desired dwarf pear rootstocks for high-density plantation to aid easy orchard management and high yielding of pear fruits.

Genome-Wide Identification of Genes Encoding for Rho-Related Proteins in 'Duli' Pear (Pyrus betulifolia Bunge) and Their Expression Analysis in Response to Abiotic Stress.

Twelve Rho-related proteins (ROPs), namely PbROPs, were identified from the genome of the recently sequenced 'Duli' pear (Pyrus betulifolia Bunge), a wild-type pear variety routinely used for rootstocks in grafting in China. The length and molecular weight of these proteins are between 175 and 215 amino acids and 19.46 and 23.45 kDa, respectively. The 12 PbROPs are distributed on 8 of the 17 chromosomes, where chromosome 15 has the highest number of 3 PbROPs. Analysis of the deduced protein sequences showed that they are relatively conserved and all have the G domain, insertion sequence, and HVR motif. The expression profiles were monitored by quantitative RT-PCR, which showed that these 12 PbROP genes were ubiquitously expressed, indicating their involvement in growth and development throughout the life cycle of 'Duli' pear. However, they were altered upon treatments with abscisic acid (ABA, mimicking abiotic stress), polyethylene glycol (PEG, mimicking drought), and sodium chloride (NaCl, mimicking salt) to tissue-cultured seedlings. Further, transgenic Arabidopsis expressing PbROP1, PbROP2, and PbROP9 exhibited enhanced sensitivity to ABA, demonstrating that these 3 PbROPs may play important roles in the abiotic stress of 'Duli' pear. The combined results showed that the 'Duli' genome encodes 12 typical ROPs and they appeared to play important roles in growth, development, and abiotic stress. These preliminary data may guide future research into the molecular mechanisms of these 12 PbROPs and their utility in molecular breeding for abiotic stress-resistant 'Duli' pear rootstocks.

Effects of Radix aconiti lateralis preparata and Rhizoma zingiberis on energy metabolism and expression of the genes related to metabolism in rats.

OBJECTIVE: To study the influence of Radix aconiti lateralis preparata and Rhizoma zingiberis, two species of Chinese medicinal herbs with hot property, on energy metabolism and gene expression spectrum, and to analyze the possible mechanism of their effects. METHODS: Forty-eight specific pathogen free Wistar rats were randomly divided into a Radix aconiti lateralis preparata group, a Rhizoma zingiberis group, and a control group. They were intragastrically treated with concentrated decoction of Radix aconiti lateralis preparata, Rhizoma zingiberis and normal saline respectively for 20 days. Toe temperature (TT), energy intake (EI), digestible energy (DE), and metabolizable energy (ME) were measured. The content of adenosine triphosphate (ATP) and energy charge (EC) in hepatic tissue were measured with high performance liquid chromatography (HPLC). The activity of ATPase and succinate dehydrogenase (SDH) in the liver were detected with chemical colorimetry. The gene expression in the liver was detected with Illumina's rat Ref-12 gene array. The differential expression genes were selected, annotated and classified based on Gene Ontology (GO). Real-time quantitative reverse-transcriptase PCR (Q-RT-PCR) was used to test the accuracy of results. RESULTS: Compared with the control group, the TT on the 10(th) day after the beginning of administration and ATP in the Radix aconiti lateralis preparata and Rhizoma zingiberis groups increased significantly (P<0.05). EI/body mass (BM), DE/BM, ME/BM, the hepatic EC and the activity of Na(+)-K(+)-ATPase, Ca(2+)-Mg(2+)-ATPase and SDH of liver increased significantly only in the Radix aconiti lateralis preparata group (P<0.05). There were 592 differential expression genes in the Radix aconiti lateralis preparata group and 1 159 in the Rhizoma zingiberis group compared with the control group. Among the differential expression genes, genes related to metabolic processes were the most significant based on GO analysis. There were 337 strips of gene differential expression in common in both Radix aconiti lateralis preparata and Rhizoma zingiberis groups compared with the control group. CONCLUSIONS: Herbs with hot property such as Radix aconiti lateralis preparata and Rhizoma zingiberis could improve the energy metabolism in rats, through influencing the metabolic process of sugar, lipid, and amino acid. It could also promote the production, storage, and utilization of energy by regulating the gene expression related to metabolism, which may be the main molecular mechanism of warming yang and dispelling cold for the treatment of the cold syndrome according to Chinese medicine theory.