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Plant defense responses at stomata and apoplast are the most important early events during plant-bacteria interactions. The key components for the signaling of stomatal defense and nonhost resistance have not been fully characterized. Here we report the newly identified small GTPase, Nucleolar GTP-binding protein 1 (NOG1), functions for plant immunity against bacterial pathogens. Virus-induced gene silencing of NOG1 compromised nonhost resistance in N. benthamiana and tomato. Comparative genomic analysis showed that two NOG1 copies are present in all known plant species: NOG1-1 and NOG1-2. Gene downregulation and overexpression studies of NOG1-1 and NOG1-2 in Arabidopsis revealed the novel function of these genes in nonhost resistance and stomatal defense against bacterial pathogens, respectively. Specially, NOG1-2 regulates guard cell signaling in response to biotic and abiotic stimuli through jasmonic acid (JA)- and abscisic acid (ABA)-mediated pathways. The results here provide valuable information on the new functional role of small GTPase, NOG1, in guard cell signaling and early plant defense in response to bacterial pathogens.

Association analysis using logistic regression analysis showed that +82466C>T and haplotypes 1(CC) and 2(CT) were associated with the development of asthma (p=0.01-0.04). The frequency of PPARG-ht2 was significantly lower in the patients with asthma compared to the normal controls in codominant and dominant models (p=0.01, p(corr)=0.03 and p=0.02, p(corr)=0.03, respectively). Conversely, the frequency of PPARG-ht1 was significantly higher in the patients with asthma compared to the normal controls in the codominant model [p=0.04, OR: 1.27 (1.01-1.6)]. In addition, the rare allele frequency of +82466C>T was significantly lower in patients with asthma in comparison to normal controls in the codominant model (OR: 0.78, p=0.04). Thus, polymorphism of the PPARG gene may be linked to an increased risk of asthma development.

Plant defense responses at stomata and apoplast are the most important early events during plant–bacteria interactions. The key components of stomatal defense responses have not been fully characterized. A GTPase encoding gene, NOG1-2, which is required for stomatal innate immunity against bacterial pathogens, was recently identified. Functional studies in Arabidopsis revealed that NOG1-2 regulates guard cell signaling in response to biotic and abiotic stimulus through jasmonic acid (JA)- and abscisic acid (ABA)-mediated pathways. Interestingly, in this study, Jasmonate-ZIM-domain protein 9 (JAZ9) was identified to interact with NOG1-2 for the regulation of stomatal closure. Upon interaction, JAZ9 reduces GTPase activity of NOG1-2. We explored the role of NOG1-2 binding with JAZ9 for COI1-mediated JA signaling and hypothesized that its function may be closely linked to MYC2 transcription factor in the regulation of the JA-signaling cascade in stomatal defense against bacterial pathogens. Our study provides valuable information on the function of a small GTPase, NOG1-2, in guard cell signaling and early plant defense in response to bacterial pathogens.

Agrobacterium-mediated plant transformation (AMT) is the basis of modern-day plant biotechnology. One major drawback of this technology is the recalcitrance of many plant species/varieties to Agrobacterium infection, most likely caused by elicitation of plant defense responses. Here, we develop a strategy to increase AMT by engineering Agrobacterium tumefaciens to express a type III secretion system (T3SS) from Pseudomonas syringae and individually deliver the P. syringae effectors AvrPto, AvrPtoB, or HopAO1 to suppress host defense responses. Using the engineered Agrobacterium, we demonstrate increase in AMT of wheat, alfalfa and switchgrass by ~250%–400%. We also show that engineered A. tumefaciens expressing a T3SS can deliver a plant protein, histone H2A-1, to enhance AMT. This strategy is of great significance to both basic research and agricultural biotechnology for transient and stable transformation of recalcitrant plant species/varieties and to deliver proteins into plant cells in a non-transgenic manner.

Ribosomal proteins are an integral part of ribosomes and are involved in their biogenesis and assembly, thus regulating protein synthesis. It is difficult to attribute an individual function of translational activity to a single ribosomal protein. This difficulty is rooted in the highly cooperative nature of the interactions between ribosomal ribonucleic acid (rRNA) and ribosomal proteins. Ribosomal proteins regulate their own synthesis by controlling the expression of their transcripts in association with transcription factors. The ribosome consists of large and small subunits. In eukaryotes, 47 ribosomal protein large (RPL) subunits and 32 ribosomal protein small (RPS) subunits form a ribosome complex with rRNAs (Ben-Shem et al., 2011). Interestingly, extraribosomal functions of many ribosomal proteins have been reported (Wool, 1996; Freed et al., 2010). Several ribosomal protein-encoding genes are shown to be differentially

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Thymosin β10 is a monomeric actin sequestering protein that regulates actin dynamics. Previously, we and others have shown that thymosin β10 acts as an actin-mediated tumor suppressor. In this study, we show that thymosin β10 is not only a cytoskeletal regulator, but that it also acts as a potent inhibitor of angiogenesis and tumor growth by its interaction with Ras. We found that overexpressed thymosin β10 significantly inhibited vascular endothelial growth factor–induced endothelial cell proliferation, migration, invasion, and tube formation in vitro. Vessel sprouting was also inhibited ex vivo. We further show that thymosin β10 directly interacted with Ras. This interaction resulted in inhibition of the Ras downstream mitogen-activated protein kinase/extracellular signal-regulated kinase kinase signaling pathway, leading to decreased vascular endothelial growth factor production. Thymosin β10 injected into a xenograft model of human ovarian cancer in nude mice markedly inhibited tumor growth and reduced tumor vascularity. In contrast, a related thymosin family member, thymosin β4, did not bind to Ras and showed positive effects on angiogenesis. These findings show that the inhibition of Ras signal transduction by thymosin β10 results in antiangiogenic and antitumor effects, suggesting that thymosin β10 may be valuable in anticancer therapy.