Adiponectin, an adipocyte-specific secretory protein, is present in serum as three oligomeric complexes. Apart from its roles as an anti-diabetic and anti-atherogenic hormone, adiponectin has been implicated as an important regulator of cell growth and tissue remodeling. Here we show that some of these functions might be mediated by the specific interactions of adiponectin with several important growth factors. Among six different growth factors examined, adiponectin was found to bind with platelet-derived growth factor BB (PDGF-BB), basic fibroblast growth factor (FGF), and heparinbinding epidermal growth factor-like growth factor (HB EGF) with distinct affinities. The bindings of adiponectin with these growth factors are oligomerization-dependent. PDGF-BB bound to the high molecular weight (HMW) and middle molecular weight (MMW) complexes, but not to the low molecular weight (LMW) complex of adiponectin. Basic FGF preferentially interacted with the HMW form, whereas HB EGF bound to all three forms with comparable affinities. These three growth factors did not compete with each other for their bindings to adiponectin, suggesting the involvement of distinct binding sites. The interactions of adiponectin with PDGF-BB, basic FGF, and HB EGF precluded the bindings to their respective membrane receptors and attenuated the DNA synthesis and cell proliferation induced by these growth factors. Small interfering RNA-mediated down-regulation of adiponectin receptors did not affect the suppressive effects of adiponectin on cell proliferation stimulated by these growth factors. These data collectively suggest that the oligomeric complexes of adiponectin can modulate the biological actions of several growth factors by controlling their bioavailability at a pre-receptor level and that this effect might partly account for the anti-atherogenic, anti-angiogenic, and anti-proliferative functions of adiponectin.Adiponectin (also called AdipoQ, ACRP30, GBP28, and aPM1) is an abundant circulating hormone predominantly expressed from adipose tissue (1-4). The protein belongs to the complement factor C1q-like superfamily and is composed of an NH 2 -terminal collagenous region (with a 22-GXY repeat) and a COOH-terminal globular domain. We have previously demonstrated that several conserved lysine residues within the collagenous domain of adiponectin are hydroxylated and glycosylated by the addition of a glucosyl-␣-1,2-galactosyl group (5, 6). In the circulation, adiponectin forms different oligomeric complexes, including high molecular weight (HMW), 1 middle molecular weight (MMW), and low molecular weight (LMW) species (5, 7-9). Growing evidence suggests that adiponectin is an insulin-sensitizing hormone with direct anti-diabetic, antiatherogenic, and anti-inflammatory activities.The circulating levels of adiponectin are decreased in obese individuals and patients with type 2 diabetes, hypertension, and coronary heart diseases (10 -13). Adiponectin replacement therapy has been shown to decrease hyperglycemia and hypertriglyceridemia,...

The CRISPR/Cas9 system has successfully been used in various organisms for precise targeted gene editing. Although it has been demonstrated that CRISPR/Cas9 system can induce mutation in tomato plants, the stability of heredity in later generations and mutant specificity induced by the CRISPR/Cas9 system in tomato plants have not yet been elucidated in detail. In this study, two genes, SlPDS and SlPIF4, were used for testing targeted mutagenesis in tomato plants through an Agrobacterium tumefaciens-mediated transformation method. A high mutation frequency was observed in all tested targets in the T0 transgenic tomato plants, with an average frequency of 83.56%. Clear albino phenotypes were observed for the psd mutants. High frequencies of homozygous and biallelic mutants were detected even in T0 plants. The majority of the detected mutations were 1- to 3-nucleotide deletions, followed by 1-bp insertions. The target mutations in the T0 lines were stably transmitted to the T1 and T2 generations, without new modifications or revision. Off-target activities associated with SlPDS and SlPIF4 were also evaluated by sequencing the putative off-target sites, and no clear off-target events were detected. Our results demonstrate that the CRISPR/Cas9 system is an efficient tool for generating stable and heritable modifications in tomato plants.

BackgroundThe mitogen-activated protein kinase (MAPK) cascade consists of three types of reversibly phosphorylated kinases, namely, MAPK, MAPK kinase (MAPKK/MEK), and MAPK kinase kinase (MAPKKK/MEKK), playing important roles in plant growth, development, and defense response. The MAPK cascade genes have been investigated in detail in model plants, including Arabidopsis, rice, and tomato, but poorly characterized in cucumber (Cucumis sativus L.), a major popular vegetable in Cucurbitaceae crops, which is highly susceptible to environmental stress and pathogen attack.ResultsA genome-wide analysis revealed the presence of at least 14 MAPKs, 6 MAPKKs, and 59 MAPKKKs in the cucumber genome. Phylogenetic analyses classified all the CsMAPK and CsMAPKK genes into four groups, whereas the CsMAPKKK genes were grouped into the MEKK, RAF, and ZIK subfamilies. The expansion of these three gene families was mainly contributed by segmental duplication events. Furthermore, the ratios of non-synonymous substitution rates (Ka) and synonymous substitution rates (Ks) implied that the duplicated gene pairs had experienced strong purifying selection. Real-time PCR analysis demonstrated that some MAPK, MAPKK and MAPKKK genes are preferentially expressed in specific organs or tissues. Moreover, the expression levels of most of these genes significantly changed under heat, cold, drought, and Pseudoperonospora cubensis treatments. Exposure to abscisic acid and jasmonic acid markedly affected the expression levels of these genes, thereby implying that they may play important roles in the plant hormone network.ConclusionA comprehensive genome-wide analysis of gene structure, chromosomal distribution, and evolutionary relationship of MAPK cascade genes in cucumber are present here. Further expression analysis revealed that these genes were involved in important signaling pathways for biotic and abiotic stress responses in cucumber, as well as the response to plant hormones. Our first systematic description of the MAPK, MAPKK, and MAPKKK families in cucumber will help to elucidate their biological roles in plant.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1621-2) contains supplementary material, which is available to authorized users.